From f1788ff78085b6291f029cf37fba833795c393fb Mon Sep 17 00:00:00 2001 From: cedounet <134267244+cedounet@users.noreply.github.com> Date: Fri, 14 Jul 2023 12:53:26 +0100 Subject: [PATCH] Reorg troubleshooting (#150) * Reorganize troubleshooting section - Classified in subcategories hopefully more logically * Reorganise troubleshooting section step 2 Now put crust debugging later. I am not sure this is fundamental, but maybe just showing my lack of experience here... * Improve table of contents - Use short ToC entry when needed - Remove extra space now that we do not have large numbers in section names anymore --- book/book.tex | 1 - book/sourdough.sty | 5 - .../crumb-structures.tex | 0 book/troubleshooting/misc.tex | 991 +++++++++--------- 4 files changed, 500 insertions(+), 497 deletions(-) rename book/troubleshooting/{crumb-structures => }/crumb-structures.tex (100%) diff --git a/book/book.tex b/book/book.tex index f3efa29..1022007 100644 --- a/book/book.tex +++ b/book/book.tex @@ -69,7 +69,6 @@ \input{storing-bread/storing-bread} \chapter{Troubleshooting} -\input{troubleshooting/crumb-structures/crumb-structures} \input{troubleshooting/misc} \printbibliography diff --git a/book/sourdough.sty b/book/sourdough.sty index 2d4d21b..e151a1d 100644 --- a/book/sourdough.sty +++ b/book/sourdough.sty @@ -63,8 +63,3 @@ \DeclareSIUnit\degF{\text{°}F} - -\RedeclareSectionCommand[ - tocindent=0pt, - tocnumwidth=35pt, -]{section} diff --git a/book/troubleshooting/crumb-structures/crumb-structures.tex b/book/troubleshooting/crumb-structures.tex similarity index 100% rename from book/troubleshooting/crumb-structures/crumb-structures.tex rename to book/troubleshooting/crumb-structures.tex diff --git a/book/troubleshooting/misc.tex b/book/troubleshooting/misc.tex index 17e842a..7b2c79e 100644 --- a/book/troubleshooting/misc.tex +++ b/book/troubleshooting/misc.tex @@ -1,72 +1,435 @@ -\section{Baking in the tropics} +\section{Starter} +\subsection{My starter does not double in size} -Depending on the temperature, your fermentation speed adapts. -In a warmer environment, everything is faster. In a colder -environment, everything is slower. +Some bakers call for the sourdough starter to +double in size before using it. +The idea is to use the sourdough starter at +peak performance to ensure a +balanced fermentation in the main dough. -This includes the speed at which your sourdough ferments -the dough but also the speed of enzymatic reactions. The -amylase and protease enzymes work faster, making more -sugars available and degrading the gluten proteins. +The doubling in size metric should be +taken with a grain of salt when judging +your starter. Depending on the flour +you use to feed the starter, different levels +of its rising can be expected. +For instance, if you use rye flour then only +very little gas from the +fermentation can be retained inside the +starter. In consequence, your +sourdough starter will not rise as much. It +could still be in healthy shape. If you use wheat flour with less gluten, +the starter will not rise as +much either. The reason is that you have a weaker +gluten network resulting in +more gas dispersing out of your dough. -At around 22°C (72°F) in my kitchen my bulk fermentation is ready -after around 10~hours. I~use around \qty{20}{\percent} of sourdough -starter based on the flour. In summertime the temperatures -in my kitchen sometimes increase to 25°C (77°F). In that case -I~reduce the sourdough starter to around \qty{10}{\percent}. +That being said, it is recommended that you develop +your volume increase +metric. Your starter will increase in size and then +ultimately lose structure +and collapse. Observe the point before it collapses. +This is the point when +you should use your starter. This could be a + \qty{50}{\percent} volume increase, 100 +percent or \qty{200}{\percent}. It is always better to use +the starter a little bit +too early rather than too late. If you use the +starter later, reduce the +quantity that you use. If the recipe calls for a 20 +percent starter quantity, +use only 10 +percent starter in that case. Your starter will +regrow in your main dough. -If I~didn't do that, my fermentation would be done after -around 4--7~hours. The problem is that the dough is quite -unstable when fermenting at this high speed. This means -that you easily run into issues of over-fermentation. -Finding the perfect sweet spot between fermenting enough -and not too much becomes much harder. Normally you might -have a time window of 1 hour. But at the rapid speed it -might be reduced to a time window of 20~minutes. Now at -30°C (86°F), everything moves much faster. Your bulk -fermentation might be complete in 2--4~hours when using -\qtyrange{10}{20}{\percent} starter. Proofing your dough in the fridge -becomes almost impossible. As your dough cools down in the -fridge the fermentation also slows down. However cooling the -dough down from 30°C to 4--6°C in your fridge takes much -longer. Your dough is much more active compared to a dough -that starts at a temperature of 20--25°C. You might -end up overproofing your dough if you leave it overnight -in the fridge. +On top of relying on the size increase, start +taking note of your starter's +smell. Over time you will be able to judge its +fermentation state based on the +smell. The stronger the smell becomes, the further +your dough has fermented. +This is a sign that you should use less starter +when making the actual dough. -That's why I~recommend that you reduce the amount of starter -that you use in the tropics to around \qtyrange{1}{5}{\percent} -based on the flour. This will slow down the fermentation -process significantly and provides you a bigger window -of time. Try to aim for an overall bulk fermentation of at -least 8--10~hours. Reduce the amount of starter to get there. +Please refer to +subsection~\ref{section:readying-starter}~``\nameref{section:readying-starter}'' +for more information on the topic. -When making dough, try to use the same water temperature -as your ambient temperature. Assuming that the temperature -will climb to 30°C, try to start your dough -with 30°C water. This means that you can carefully rely on -a small fermentation sample (aliquot jar) that visualizes your fermentation -progress. To read more about this technique refer -to Section~\ref{section:bulk-fermentation}. -The sample only works reliably if your dough temperature -is equal to your ambient temperature. Else the sample heats -up or cools down faster. So tread carefully when using -the sample in this case. It's always better to stop -the fermentation a little too early rather than too late. -Stretch and folds during the bulk fermentation -will help you to develop a better feel for -the dough. An expensive but possibly useful tool -could be a pH meter that allows you to perfectly -measure how much acidity has been created by the -lactic and acetic acid bacteria. In this case measure -the pH repeatedly and figure out a value that works -for your sourdough. In my case I~tend to end bulk -fermentation at a pH of around 4.1. Please don't just -follow my pH value; it's very individual. Keep measuring -with different doughs to find out a value that works for you. -\section{My bread stays flat} +\subsection{What's the best starter feeding ratio?} + +The best starter feeding ratio is commonly either 1:5:5 or 1:10:10. +In the case of 1:5:5 that's 1 part old starter, +5 parts flour and 5 parts water. If you are using a stiff starter, +use half the amount of water. So that's 1:5:2.5. Depending on when +you last fed your starter 1:10:10 might make more sense. If the starter +is old and hasn't been fed recently the 1:10:10 ratio is a better choice. +By reducing the starter inoculation ratio, you provide the microorganisms +with a cleaner environment. This way they can reproduce and regrow +into a more desirable balance to begin your dough fermentation. + +Generally, think of your sourdough starter as a dough. Use the same +ratios you use for your bread dough for your starter. Your starter +should be trained in the same environment that you later use +for your dough. This way your starter is perfectly suited to +ferment the dough into which it is later inoculated. + +The only exception to the 1:5:5 and 1:10:10 rule is the initial +starter set-up stage. For the first days during the starter-making +process there aren't enough microbes yet. So using a 1:1:1 ratio +can speed up the process. +\subsection{What's the benefit of using a stiff sourdough starter?} + +A regular sourdough starter has equal parts of +flour and water (\qty{100}{\percent} hydration). A stiffer +sourdough starter features a hydration level of 50 to \qty{60}{\percent}. + +The stiff sourdough starter boosts the yeast part +of your starter more. This way your gluten degrades +slower and you can ferment for a longer period. This +is especially handy when baking with lower gluten flours. + +You can read more about the topic of stiff sourdough +starters in subsection~\ref{section:stiff-starter}. + +\subsection{What's the benefit of using a liquid sourdough starter?} + +The liquid starter will boost anaerobic bacterial +fermentation in your starter. This way your starter +tends to produce more lactic acid rather than acetic +acid. Lactic acid is perceived as milder and more +yogurty. Acetic acid can sometimes taste quite +pungent. Acetic acid can be perfect when making +dark rye bread but not so much when making a fluffy +ciabatta-style loaf. + +When converting your starter to a liquid starter you are +permanently altering the microbiome of your starter. +You cannot go back once you have eliminated acetic +acid-producing bacteria. So it is recommended to keep +a backup of your original starter. + +A downside to the liquid starter is the overall +enhanced bacterial activity. This means the baked bread +will have more acidity (but milder). The dough will degrade +faster during fermentation. For this reason, you +will need to use strong high-gluten flour when using +this type of starter. + +You can read more about the liquid starter +in subsection~\ref{section:liquid-starter} + +\subsection{My new starter doesn't rise at all} + +Make sure that you use unchlorinated water. +In many areas of the world, tap water has +chlorine added to kill microorganisms. If that's +the case in your region, bottled spring water will +help. +You can also use a water filter with activated charcoal +which will remove the chlorine. +Alternatively, if you draw tap water into a pitcher or other +container and let it sit, loosely covered, the chlorine +should dissipate within 12--24~hours, and you have +the added advantage of automatically having +room-temperature water. + +Make sure to use whole grain flour (whole wheat, whole rye, etc.). +These flours have more natural wild yeast and +bacterial contamination. Making a starter +from just white flour sometimes doesn't work. +Try to use organic unbleached flour to make +the starter. Industrial flour can sometimes +be treated with fungicides. + +\subsection{I~made a starter, it rose on day 3 and now not anymore} + +This is normal. As your starter is maturing, different +microorganisms are activated. Especially during +the first days of the process, bad microbes +like mold can be activated. These cause your +starter to rise a lot. With each subsequent +starter-feeding, you select the microbes that are best +at fermenting flour. For this reason, it is +recommended to discard the leftover unused starter +from the first days of the process. Later on, unneeded +starter amounts should never be thrown away. You can make +great discard bread out of it. + +So just keep going and don't give up. The first big +rise is an indicator that you are doing everything +right. Based on my experience, it takes around 7 +days to grow a starter. As you feed your starter +more and more, it will become even better at fermenting +flour. The first bread might not go exactly as you +planned, but you will get there eventually. Each +feeding makes your starter stronger and stronger. + +\subsection{Liquid on top of my starter} + +Sometimes a liquid, in many cases black liquid, gathers on top +of your sourdough starter. The liquid might have a pungent +smell to it. Many people confuse this with mold. I~have seen +bakers recommending to discard the starter because of this liquid. +The liquid is commonly known as \emph{hooch}. After a while +of no activity the heavier flour separates from the water. The flour +will sit at the bottom of your jar and the liquid will stay on top. +The liquid turns darker because some particles of the flour weigh +less than the water and float on top. Furthermore dead microorganisms +float in this liquid. This liquid is not a bad thing; it's actively +protecting your sourdough starter from aerobic mold entering through +the top. + +\begin{figure}[!htb] +\begin{center} + \includegraphics[width=0.5\textwidth]{hooch} + \caption{Hooch building on top of a sourdough starter~\cite{liquid+on+starter}.}% + \label{fig:hooch} +\end{center} +\end{figure} + +Simply stir your sourdough starter to homogenize the hooch back +into your starter. The hooch will disappear. Then use a little bit of +your sourdough starter to set up the starter for your next bread. +Once hooch appears, your starter has likely fermented for a long +period of time. It might be very sour. This state of starter +is excellent to make discard crackers or a discard bread. Don't throw +anything away. Your hooch is a sign that you have a long fermented +dough in front of you. Compare it to a 2 year ripened Parmigiano cheese. +The dough in front of you is full of delicious flavor. + +\subsection{Fixing a moldy sourdough starter} + +First of all, making a moldy sourdough starter is very difficult. +It's an indicator that something might be completely off in your starter. +Normally the symbiosis of yeast and bacteria does not allow external +pathogens such as mold to enter your sourdough starter. +The low pH created by the bacteria is a very hostile environment +that no other pathogens like. Generally everything below a pH +of 4.2 can be considered food safe~\cite{food+safe+ph}. This +is the concept of pickled foods. And your sourdough bread +is essentially pickled bread. + +I~have seen this happening especially when the sourdough +starter is relatively young. Each flour naturally contains +mold spores. When beginning a sourdough starter, all +the microorganisms start to compete by metabolizing the +flour. Mold can sometimes win the race and outcompete +the natural wild yeast and bacteria. In that case simply +try cultivating your sourdough starter again. If mold reappears +again, it might be a very moldy batch of flour. Try a different +flour to begin your sourdough starter with. + +Mature sourdough starters should not go moldy unless the conditions +of the starter change. I~have seen mold appearing when the starter is stored +in the fridge and the surface dried out. It also sometimes forms on the +edges of your starter's container, typically in areas where no active +starter microorganisms can reach. Simply try to extract an +area of your starter that has no mold. Feed it again with flour and +water. After a few feedings, your starter should be back to normal. +Take only a tiny bit of starter: \qtyrange{1}{2}{\gram} are enough. They already +contain millions of microorganisms. + +Mold favors aerobic conditions. This means that air is required in order +for the mold fungus to grow. Another technique that has worked for me +was to convert my sourdough starter into a liquid starter. This successfully +shifted my starter from acetic acid production to lactic acid production. +Acetic acid, similarly to mold, requires oxygen to be produced. After +submerging the flour with water, over time the lactic acid bacteria +outcompeted the acetic acid bacteria. This is a similar concept to pickled +foods. By doing this you are essentially killing all live mold fungi. You +might only have some spores left. With each feeding the spores will become +fewer and fewer. Furthermore, it seems that lactic acid bacteria produce +metabolites that inhibit mold growth~\cite{mold+lactic+acid+bacteria}. + +\begin{figure}[!htb] + \includegraphics[width=\textwidth]{fungi-lactic-acid-interactions} + \caption{The interaction of lactic acid bacteria and mold fungi. + In~\cite{mold+lactic+acid+bacteria}, \citeauthor{mold+lactic+acid+bacteria} +et al.\ show how bacteria are producing metabolites that inhibit fungus +growth.}% + \label{fig:fungi-lactic-acid-interactions} +\end{figure} + +To pickle your starter, simply take a bit of your existing starter (\qty{5}{\gram} for +instance). Then feed the mixture with \qty{20}{\gram} of flour and \qty{100}{\gram} of water. You have +created a starter with a hydration of around \qty{500}{\percent}. Shake the mixture vigorously. +After a few hours you should start seeing most of the flour near the bottom +of your container. After a while most of the oxygen from the bottom mixture +is depleted and anaerobic lactic acid bacteria will start to thrive. Take a +note of the smell your sourdough starter. If it was previously acetic +it will now change to be a lot more dairy. Extract a bit of your mixture the +next day by shaking everything first. Take \qty{5}{\gram} of the previous mixture, feed +again with another \qty{20}{\gram} of flour and another \qty{100}{\gram} of water. After 2--3 +additional feedings your starter should have adapted. When switching back +to a hydration of \qty{100}{\percent} the mold should have been eliminated. Please note that +more tests should be conducted on this topic. It would be nice to really +carefully analyze the microorganisms before the pickling and after. + +\subsection{My sourdough starter is too sour} + +If your sourdough starter is too sour it will cause problems during +the fermentation. Your fermentation will have more +bacterial activity than yeast activity. This means +you will likely create a more tangy loaf which isn't +as fluffy as it could be. The goal is to reach the right +balance: Fluffy consistency from the yeast and a great, +not-too-strong tang from the bacteria. This depends +of course on what you are looking for in terms of taste +in your bread. When making rye bread, I~prefer to be more +on the tangy side for instance. When the described balance +is off, the first thing to check is your sourdough starter. + +Note the smell of your starter. Does it smell very sour? +Taste a bit of your starter too. How sour does it taste? +Over time, every starter becomes more and more sour the longer +you wait. But sometimes your starter becomes sour too fast. +In this case apply daily feedings to your starter. Reduce +the amount of old starter that you use to feed. A ratio +of 1:5:5 or 1:10:10 can do wonders. In this case you would +take 1 part of starter (\qty{10}{\gram}) and feed it with \qty{50}{\gram} of flour +and \qty{50}{\gram} of water. This way the microorganisms start +the fermentation in a greenfield environment. This is +similar to the \qty{10}{\percent} starter or \qty{20}{\percent} starter +ratio that you use to make a dough. These days I~almost +never use a 1:1:1 ratio. This only makes sense when you +are initially creating your starter. You want a sour +environment so that your microorganisms outcompete +potential pathogens. The acidic environment is toxic +to most pathogens that you do not want in your starter. + +Another approach that can help is to convert your +sourdough starter into a stiff starter as +described in subsection~\ref{subsection:stiff-starter}. + +\subsection{Why does my starter smell like vinegar or acetone?} + +Your sourdough starter has likely produced a lot of acetic acid. +Acetic acid is essential when creating vinegar. Once no additional +food is left some of your starter's bacteria will consume ethanol +and convert it into acetic acid. Acetic acid has a very pungent smell. +When tasting acetic acid, the flavor of your bread is often perceived +as quite strong. + +\begin{figure}[!htb] +\begin{center} + \input{figures/fig-ethanol-oxidation.tex} + \caption{Oxygen is required to create acetic acid~\cite{acetic+acid+production}.}% + \label{fig:ethanol-oxidation} +\end{center} +\end{figure} + +This is nothing bad. But if you would like to change +the flavor of your final bread, consider converting +your sourdough starter into a liquid starter. This will +help to prioritize lactic acid-producing bacteria. +Your flavor will change to dairy compared to vinegary. +You can't go back though. After the conversion your starter +will never go back to acetic acid production because you have +changed the tides towards primarily lactic acid fermentation. +I~like to have a separate rye starter. In my experiments +rye starters tend to feature many acetic acid bacteria. +This starter is excellent when you want to make a very hearty, +strong-tasting bread. A pure rye bread tastes excellent when +made with such a starter. The flavor when taking a bite +is incredible. It nicely plays with soups as well. Just take +a bit of this bread and dip it in your soup. + +\section{Dough} +\subsection{Should I~autolyse my dough?} + +In \qty{95}{\percent} of all cases, an autolysis +makes no sense. Instead I~recommend +that you conduct a fermentolysis. You +can read more about the autolysis process in +Section~\ref{section:autolysis} and +more about the topic of fermentolysis +in Section~\ref{section:fermentolysis}. + +The fermentolysis combines all the benefits +of the autolysis while eliminating disadvantages +such as having to knead the dough multiple times. + +The autolysis only makes sense when you might +bake a fast-fermenting yeast-based dough with a +high yeast inoculation rate. But even in that +case you could just lower the amount of yeast +to fermentolyse rather than autolyse. + +\subsection{My dough sample (aliquot) doesn't rise. What's wrong?} + +If you see that your dough rises in size but your aliquot doesn't, chances +are that both are fermenting at different speeds. This can often +happen when the temperature in your kitchen changes. The aliquot +is more susceptible to temperature changes than the main dough. +Because the sample is smaller in size, it will heat up or cool down +faster. + +For this reason, you must use room-temperature water when +making your dough. By having the same temperature in both the sample +and your dough, you make sure that both ferment at the same rate. + +If the temperature in your room changes significantly during the day, your +best option is to use a see-through container. Mark the container to properly +measure your dough's size increase. + +Another option could be to use a more expensive pH meter to measure your +dough's acidity buildup. You can read more about different ways of managing +bulk fermentation in Section~\ref{section:bulk-fermentation}. + +\subsection{What's a good level of water (hydration) to make a dough?} + +Especially when starting to make bread, use lower amounts of water. This will +greatly simplify the whole process. I~recommend using a level of around 60 +percent hydration. So for every \qty{100}{\gram} of flour use around \qty{60}{\gram} of water. +This ballpark figure will work for most flours. With this hydration, you can +make bread, buns, pizzas, and even baguettes out of the same dough. + +With the lower hydration, dough handling becomes easier and you have more yeast +fermentation, resulting in lower over-fermentation risk. + +\subsection{My dough completely tears after a long fermentation} + +Sometimes when touching your dough after a long fermentation +it completely tears apart. This could be for two reasons. It might +be that the bacteria completely consumed the gluten of your flour. +On the other hand, over time your gluten network automatically +degrades. This is the protease enzyme converting the gluten +network into smaller amino acids the seedling can use as +building blocks for its growth. This process starts to happen +the moment you mix flour and water. The longer your dough sits, +the more gluten is broken down. As the gluten holds the +wheat dough together, your dough will ultimately tear. + +\begin{figure}[!htb] + \includegraphics[width=1.0\textwidth]{tearing-dough} + \caption{My dough tearing after 24~hours of no activity.}% + \label{fig:tearing-dough} +\end{figure} + +In the picture~\ref{fig:tearing-dough} I~experimented with +using a starter that has not been fed for 30 days at room temperature. +I~tried to make a dough directly out of the unfed starter. +Typically after a long period +without feedings your microbes start to sporulate and go +into hibernation mode. This way they can survive for a long +period of time without extra feedings. Adding additional food +will activate them again. In this case the dough did not ferment +fast enough before the protease broke down the gluten. By activating +your microbes they will start to reproduce and increase in quantity +for as long as there is food available. But this process +in my case was not fast enough. After around 24~hours, the whole +dough just started to completely tear apart. The whole process was further +accelerated by my using whole wheat flour. Whole wheat +contains more enzymes than white flour. + +To fix this, try to make sure that your sourdough starter is lively +and active. Simply apply a couple more feedings before +making your dough. This way your dough becomes ready to shape +before it has completely broken down. + +\section{Bread} +\subsection{My bread stays flat} A flat bread is in most cases related to your gluten network breaking down fully. This is not bad; this @@ -99,9 +462,9 @@ the yeast part of your starter. This allows you to have less bacterial fermentation, resulting in a stronger gluten network toward the end of the fermentation~\cite{stiff+starter}. Please -also refer to the Section~\ref{sec:overfermented-dough} where +also refer to the subsection~\ref{sec:overfermented-dough} where I~explained more about overfermented doughs. You can also -refer to Section~\ref{section:stiff-starter} with more details on +refer to subsection~\ref{section:stiff-starter} with more details on making a stiff sourdough starter. Furthermore, a stronger flour containing more gluten @@ -118,7 +481,7 @@ suddenly become very sticky after a few hours? That's a another good indicator. Please also use your nose to note the smell of the dough. It shouldn't be too pungent. -\section{I~want more tang in my bread} +\subsection{I~want more tang in my bread} To achieve more tang in your sourdough bread, you have to ferment your dough for a longer period of time. @@ -189,7 +552,7 @@ reported that the bread was overly sour and not pleasant to eat at all. When this happens to you, consider toasting the bread. Toasting will boil off additional acidity.}. -\section{My bread is too sour} +\subsection{My bread is too sour} Some people like the bread less sour as well. This is personal preference. To achieve a less sour bread @@ -220,82 +583,14 @@ I~tested a regular starter, a liquid starter and a stiff starter. The stiff starter by far created the most \ch{CO2} compared to the other starters. As a consequence, the stiff starter balloon was inflated the most~\cite{stiff+starter}. You can read more -about the topic of stiff starters in Section~\ref{section:stiff-starter}. +about the topic of stiff starters in subsection~\ref{section:stiff-starter}. Another unconventional approach could be to add baking powder to your dough. The baking powder neutralizes the lactic acid and will make a much milder dough~\cite{baking+powder+reduce-acidity}. -\section{Fixing a moldy sourdough starter} - -First of all, making a moldy sourdough starter is very difficult. -It's an indicator that something might be completely off in your starter. -Normally the symbiosis of yeast and bacteria does not allow external -pathogens such as mold to enter your sourdough starter. -The low pH created by the bacteria is a very hostile environment -that no other pathogens like. Generally everything below a pH -of 4.2 can be considered food safe~\cite{food+safe+ph}. This -is the concept of pickled foods. And your sourdough bread -is essentially pickled bread. - -I~have seen this happening especially when the sourdough -starter is relatively young. Each flour naturally contains -mold spores. When beginning a sourdough starter, all -the microorganisms start to compete by metabolizing the -flour. Mold can sometimes win the race and outcompete -the natural wild yeast and bacteria. In that case simply -try cultivating your sourdough starter again. If mold reappears -again, it might be a very moldy batch of flour. Try a different -flour to begin your sourdough starter with. - -Mature sourdough starters should not go moldy unless the conditions -of the starter change. I~have seen mold appearing when the starter is stored -in the fridge and the surface dried out. It also sometimes forms on the -edges of your starter's container, typically in areas where no active -starter microorganisms can reach. Simply try to extract an -area of your starter that has no mold. Feed it again with flour and -water. After a few feedings, your starter should be back to normal. -Take only a tiny bit of starter: \qtyrange{1}{2}{\gram} are enough. They already -contain millions of microorganisms. - -Mold favors aerobic conditions. This means that air is required in order -for the mold fungus to grow. Another technique that has worked for me -was to convert my sourdough starter into a liquid starter. This successfully -shifted my starter from acetic acid production to lactic acid production. -Acetic acid, similarly to mold, requires oxygen to be produced. After -submerging the flour with water, over time the lactic acid bacteria -outcompeted the acetic acid bacteria. This is a similar concept to pickled -foods. By doing this you are essentially killing all live mold fungi. You -might only have some spores left. With each feeding the spores will become -fewer and fewer. Furthermore, it seems that lactic acid bacteria produce -metabolites that inhibit mold growth~\cite{mold+lactic+acid+bacteria}. - -\begin{figure}[!htb] - \includegraphics[width=\textwidth]{fungi-lactic-acid-interactions} - \caption{The interaction of lactic acid bacteria and mold fungi. - In~\cite{mold+lactic+acid+bacteria}, \citeauthor{mold+lactic+acid+bacteria} -et al.\ show how bacteria are producing metabolites that inhibit fungus -growth.}% - \label{fig:fungi-lactic-acid-interactions} -\end{figure} - -To pickle your starter, simply take a bit of your existing starter (\qty{5}{\gram} for -instance). Then feed the mixture with \qty{20}{\gram} of flour and \qty{100}{\gram} of water. You have -created a starter with a hydration of around \qty{500}{\percent}. Shake the mixture vigorously. -After a few hours you should start seeing most of the flour near the bottom -of your container. After a while most of the oxygen from the bottom mixture -is depleted and anaerobic lactic acid bacteria will start to thrive. Take a -note of the smell your sourdough starter. If it was previously acetic -it will now change to be a lot more dairy. Extract a bit of your mixture the -next day by shaking everything first. Take \qty{5}{\gram} of the previous mixture, feed -again with another \qty{20}{\gram} of flour and another \qty{100}{\gram} of water. After 2--3 -additional feedings your starter should have adapted. When switching back -to a hydration of \qty{100}{\percent} the mold should have been eliminated. Please note that -more tests should be conducted on this topic. It would be nice to really -carefully analyze the microorganisms before the pickling and after. - -\section{My bread flattens out when removing it from the banneton} +\subsection{My bread flattens out when removing it from the banneton} After removing your dough from the banneton, your dough will always flatten out a bit. That's because over time your gluten network @@ -311,7 +606,7 @@ dough fully collapses and stays flat during the bake. The A related symptom is that your dough sticks to the banneton. When I~starting baking I~combated this with rice flour. It worked for me but it might be a false find. Please refer to -Section~\ref{sec:overfermented-dough} for more details on why +subsection~\ref{sec:overfermented-dough} for more details on why rice flour is not a good idea to manage sticky doughs. These days I~gently rub my @@ -326,7 +621,7 @@ If you own a pH meter, take a note of your dough's pH before baking. This will allow you to better judge your dough throughout the fermentation process. -\section{My bread flattens out during shaping} +\subsection{My bread flattens out during shaping} Similarly to a dough flattening out after removing it from the banneton, a flattened dough after shaping is also a possible sign of over-fermentation. @@ -341,73 +636,7 @@ to rescue your dough. You can also cut a piece of the dough and use it as the starter for your next dough. Your sourdough dough is essentially just a gigantic starter. -\section{Liquid on top of my starter} - -Sometimes a liquid, in many cases black liquid, gathers on top -of your sourdough starter. The liquid might have a pungent -smell to it. Many people confuse this with mold. I~have seen -bakers recommending to discard the starter because of this liquid. -The liquid is commonly known as \emph{hooch}. After a while -of no activity the heavier flour separates from the water. The flour -will sit at the bottom of your jar and the liquid will stay on top. -The liquid turns darker because some particles of the flour weigh -less than the water and float on top. Furthermore dead microorganisms -float in this liquid. This liquid is not a bad thing; it's actively -protecting your sourdough starter from aerobic mold entering through -the top. - -\begin{figure}[!htb] -\begin{center} - \includegraphics[width=0.5\textwidth]{hooch} - \caption{Hooch building on top of a sourdough starter~\cite{liquid+on+starter}.}% - \label{fig:hooch} -\end{center} -\end{figure} - -Simply stir your sourdough starter to homogenize the hooch back -into your starter. The hooch will disappear. Then use a little bit of -your sourdough starter to set up the starter for your next bread. -Once hooch appears, your starter has likely fermented for a long -period of time. It might be very sour. This state of starter -is excellent to make discard crackers or a discard bread. Don't throw -anything away. Your hooch is a sign that you have a long fermented -dough in front of you. Compare it to a 2 year ripened Parmigiano cheese. -The dough in front of you is full of delicious flavor. - -\section{Why does my starter smell like vinegar or acetone?} - -Your sourdough starter has likely produced a lot of acetic acid. -Acetic acid is essential when creating vinegar. Once no additional -food is left some of your starter's bacteria will consume ethanol -and convert it into acetic acid. Acetic acid has a very pungent smell. -When tasting acetic acid, the flavor of your bread is often perceived -as quite strong. - -\begin{figure}[!htb] -\begin{center} - \input{figures/fig-ethanol-oxidation.tex} - \caption{Oxygen is required to create acetic acid~\cite{acetic+acid+production}.}% - \label{fig:ethanol-oxidation} -\end{center} -\end{figure} - -This is nothing bad. But if you would like to change -the flavor of your final bread, consider converting -your sourdough starter into a liquid starter. This will -help to prioritize lactic acid-producing bacteria. -Your flavor will change to dairy compared to vinegary. -You can't go back though. After the conversion your starter -will never go back to acetic acid production because you have -changed the tides towards primarily lactic acid fermentation. -I~like to have a separate rye starter. In my experiments -rye starters tend to feature many acetic acid bacteria. -This starter is excellent when you want to make a very hearty, -strong-tasting bread. A pure rye bread tastes excellent when -made with such a starter. The flavor when taking a bite -is incredible. It nicely plays with soups as well. Just take -a bit of this bread and dip it in your soup. - -\section{My crust becomes chewy} +\subsection{My crust becomes chewy} Depending on which style of bread you are making a thick crackly crust is sometimes desired. The crust @@ -434,264 +663,87 @@ I~always toast each slice. This way some of the crispness returns. If you know of a great way, please reach out and I~will update this book with your findings. -\section{My dough completely tears after a long fermentation} +\input{troubleshooting/crumb-structures} -Sometimes when touching your dough after a long fermentation -it completely tears apart. This could be for two reasons. It might -be that the bacteria completely consumed the gluten of your flour. -On the other hand, over time your gluten network automatically -degrades. This is the protease enzyme converting the gluten -network into smaller amino acids the seedling can use as -building blocks for its growth. This process starts to happen -the moment you mix flour and water. The longer your dough sits, -the more gluten is broken down. As the gluten holds the -wheat dough together, your dough will ultimately tear. +\section{Misc} +\subsection{Baking in the tropics} -\begin{figure}[!htb] - \includegraphics[width=1.0\textwidth]{tearing-dough} - \caption{My dough tearing after 24~hours of no activity.}% - \label{fig:tearing-dough} -\end{figure} +Depending on the temperature, your fermentation speed adapts. +In a warmer environment, everything is faster. In a colder +environment, everything is slower. -In the picture~\ref{fig:tearing-dough} I~experimented with -using a starter that has not been fed for 30 days at room temperature. -I~tried to make a dough directly out of the unfed starter. -Typically after a long period -without feedings your microbes start to sporulate and go -into hibernation mode. This way they can survive for a long -period of time without extra feedings. Adding additional food -will activate them again. In this case the dough did not ferment -fast enough before the protease broke down the gluten. By activating -your microbes they will start to reproduce and increase in quantity -for as long as there is food available. But this process -in my case was not fast enough. After around 24~hours, the whole -dough just started to completely tear apart. The whole process was further -accelerated by my using whole wheat flour. Whole wheat -contains more enzymes than white flour. +This includes the speed at which your sourdough ferments +the dough but also the speed of enzymatic reactions. The +amylase and protease enzymes work faster, making more +sugars available and degrading the gluten proteins. -To fix this, try to make sure that your sourdough starter is lively -and active. Simply apply a couple more feedings before -making your dough. This way your dough becomes ready to shape -before it has completely broken down. +At around 22°C (72°F) in my kitchen my bulk fermentation is ready +after around 10~hours. I~use around \qty{20}{\percent} of sourdough +starter based on the flour. In summertime the temperatures +in my kitchen sometimes increase to 25°C (77°F). In that case +I~reduce the sourdough starter to around \qty{10}{\percent}. -\section{My sourdough starter is too sour} +If I~didn't do that, my fermentation would be done after +around 4--7~hours. The problem is that the dough is quite +unstable when fermenting at this high speed. This means +that you easily run into issues of over-fermentation. +Finding the perfect sweet spot between fermenting enough +and not too much becomes much harder. Normally you might +have a time window of 1 hour. But at the rapid speed it +might be reduced to a time window of 20~minutes. Now at +30°C (86°F), everything moves much faster. Your bulk +fermentation might be complete in 2--4~hours when using +\qtyrange{10}{20}{\percent} starter. Proofing your dough in the fridge +becomes almost impossible. As your dough cools down in the +fridge the fermentation also slows down. However cooling the +dough down from 30°C to 4--6°C in your fridge takes much +longer. Your dough is much more active compared to a dough +that starts at a temperature of 20--25°C. You might +end up overproofing your dough if you leave it overnight +in the fridge. -If your sourdough starter is too sour it will cause problems during -the fermentation. Your fermentation will have more -bacterial activity than yeast activity. This means -you will likely create a more tangy loaf which isn't -as fluffy as it could be. The goal is to reach the right -balance: Fluffy consistency from the yeast and a great, -not-too-strong tang from the bacteria. This depends -of course on what you are looking for in terms of taste -in your bread. When making rye bread, I~prefer to be more -on the tangy side for instance. When the described balance -is off, the first thing to check is your sourdough starter. +That's why I~recommend that you reduce the amount of starter +that you use in the tropics to around \qtyrange{1}{5}{\percent} +based on the flour. This will slow down the fermentation +process significantly and provides you a bigger window +of time. Try to aim for an overall bulk fermentation of at +least 8--10~hours. Reduce the amount of starter to get there. -Note the smell of your starter. Does it smell very sour? -Taste a bit of your starter too. How sour does it taste? -Over time, every starter becomes more and more sour the longer -you wait. But sometimes your starter becomes sour too fast. -In this case apply daily feedings to your starter. Reduce -the amount of old starter that you use to feed. A ratio -of 1:5:5 or 1:10:10 can do wonders. In this case you would -take 1 part of starter (\qty{10}{\gram}) and feed it with \qty{50}{\gram} of flour -and \qty{50}{\gram} of water. This way the microorganisms start -the fermentation in a greenfield environment. This is -similar to the \qty{10}{\percent} starter or \qty{20}{\percent} starter -ratio that you use to make a dough. These days I~almost -never use a 1:1:1 ratio. This only makes sense when you -are initially creating your starter. You want a sour -environment so that your microorganisms outcompete -potential pathogens. The acidic environment is toxic -to most pathogens that you do not want in your starter. +When making dough, try to use the same water temperature +as your ambient temperature. Assuming that the temperature +will climb to 30°C, try to start your dough +with 30°C water. This means that you can carefully rely on +a small fermentation sample (aliquot jar) that visualizes your fermentation +progress. To read more about this technique refer +to Section~\ref{section:bulk-fermentation}. -Another approach that can help is to convert your -sourdough starter into a stiff starter as -described in Section~\ref{section:stiff-starter}. +The sample only works reliably if your dough temperature +is equal to your ambient temperature. Else the sample heats +up or cools down faster. So tread carefully when using +the sample in this case. It's always better to stop +the fermentation a little too early rather than too late. +Stretch and folds during the bulk fermentation +will help you to develop a better feel for +the dough. An expensive but possibly useful tool +could be a pH meter that allows you to perfectly +measure how much acidity has been created by the +lactic and acetic acid bacteria. In this case measure +the pH repeatedly and figure out a value that works +for your sourdough. In my case I~tend to end bulk +fermentation at a pH of around 4.1. Please don't just +follow my pH value; it's very individual. Keep measuring +with different doughs to find out a value that works for you. -\section{My starter does not double in size} - -Some bakers call for the sourdough starter to -double in size before using it. -The idea is to use the sourdough starter at -peak performance to ensure a -balanced fermentation in the main dough. - -The doubling in size metric should be -taken with a grain of salt when judging -your starter. Depending on the flour -you use to feed the starter, different levels -of its rising can be expected. -For instance, if you use rye flour then only -very little gas from the -fermentation can be retained inside the -starter. In consequence, your -sourdough starter will not rise as much. It -could still be in healthy shape. If you use wheat flour with less gluten, -the starter will not rise as -much either. The reason is that you have a weaker -gluten network resulting in -more gas dispersing out of your dough. - -That being said, it is recommended that you develop -your volume increase -metric. Your starter will increase in size and then -ultimately lose structure -and collapse. Observe the point before it collapses. -This is the point when -you should use your starter. This could be a - \qty{50}{\percent} volume increase, 100 -percent or \qty{200}{\percent}. It is always better to use -the starter a little bit -too early rather than too late. If you use the -starter later, reduce the -quantity that you use. If the recipe calls for a 20 -percent starter quantity, -use only 10 -percent starter in that case. Your starter will -regrow in your main dough. - -On top of relying on the size increase, start -taking note of your starter's -smell. Over time you will be able to judge its -fermentation state based on the -smell. The stronger the smell becomes, the further -your dough has fermented. -This is a sign that you should use less starter -when making the actual dough. - -Please refer to -Section~\ref{section:readying-starter}~``\nameref{section:readying-starter}'' -for more information on the topic. - -\section{Should I~autolyse my dough?} - -In \qty{95}{\percent} of all cases, an autolysis -makes no sense. Instead I~recommend -that you conduct a fermentolysis. You -can read more about the autolysis process in -Section~\ref{section:autolysis} and -more about the topic of fermentolysis -in Section~\ref{section:fermentolysis}. - -The fermentolysis combines all the benefits -of the autolysis while eliminating disadvantages -such as having to knead the dough multiple times. - -The autolysis only makes sense when you might -bake a fast-fermenting yeast-based dough with a -high yeast inoculation rate. But even in that -case you could just lower the amount of yeast -to fermentolyse rather than autolyse. - -\section{What's the benefit of using a stiff sourdough starter?} - -A regular sourdough starter has equal parts of -flour and water (\qty{100}{\percent} hydration). A stiffer -sourdough starter features a hydration level of 50 to \qty{60}{\percent}. - -The stiff sourdough starter boosts the yeast part -of your starter more. This way your gluten degrades -slower and you can ferment for a longer period. This -is especially handy when baking with lower gluten flours. - -You can read more about the topic of stiff sourdough -starters in Section~\ref{section:stiff-starter}. - -\section{What's the benefit of using a liquid sourdough starter?} - -The liquid starter will boost anaerobic bacterial -fermentation in your starter. This way your starter -tends to produce more lactic acid rather than acetic -acid. Lactic acid is perceived as milder and more -yogurty. Acetic acid can sometimes taste quite -pungent. Acetic acid can be perfect when making -dark rye bread but not so much when making a fluffy -ciabatta-style loaf. - -When converting your starter to a liquid starter you are -permanently altering the microbiome of your starter. -You cannot go back once you have eliminated acetic -acid-producing bacteria. So it is recommended to keep -a backup of your original starter. - -A downside to the liquid starter is the overall -enhanced bacterial activity. This means the baked bread -will have more acidity (but milder). The dough will degrade -faster during fermentation. For this reason, you -will need to use strong high-gluten flour when using -this type of starter. - -You can read more about the liquid starter -in Section~\ref{section:liquid-starter} - -\section{My new starter doesn't rise at all} - -Make sure that you use unchlorinated water. -In many areas of the world, tap water has -chlorine added to kill microorganisms. If that's -the case in your region, bottled spring water will -help. -You can also use a water filter with activated charcoal -which will remove the chlorine. -Alternatively, if you draw tap water into a pitcher or other -container and let it sit, loosely covered, the chlorine -should dissipate within 12--24~hours, and you have -the added advantage of automatically having -room-temperature water. - -Make sure to use whole grain flour (whole wheat, whole rye, etc.). -These flours have more natural wild yeast and -bacterial contamination. Making a starter -from just white flour sometimes doesn't work. -Try to use organic unbleached flour to make -the starter. Industrial flour can sometimes -be treated with fungicides. - -\section{I~made a starter, it rose on day 3 and now not anymore} - -This is normal. As your starter is maturing, different -microorganisms are activated. Especially during -the first days of the process, bad microbes -like mold can be activated. These cause your -starter to rise a lot. With each subsequent -starter-feeding, you select the microbes that are best -at fermenting flour. For this reason, it is -recommended to discard the leftover unused starter -from the first days of the process. Later on, unneeded -starter amounts should never be thrown away. You can make -great discard bread out of it. - -So just keep going and don't give up. The first big -rise is an indicator that you are doing everything -right. Based on my experience, it takes around 7 -days to grow a starter. As you feed your starter -more and more, it will become even better at fermenting -flour. The first bread might not go exactly as you -planned, but you will get there eventually. Each -feeding makes your starter stronger and stronger. - -\section{My flour has low gluten content --- what should I~do?} +\subsection{My flour has low gluten content --- what should I~do?} You can always mix in a little bit of vital wheat gluten. Vital wheat gluten is concentrated extracted gluten from wheat flour. -I~recommend that you add around \qty{5}{\gram} of wheat gluten for every \qty{100}{\gram} of -flour that you are using. +I~recommend that you add around \qty{5}{\gram} of wheat gluten for every +\qty{100}{\gram} of flour that you are using. -\section{What's a good level of water (hydration) to make a dough?} - -Especially when starting to make bread, use lower amounts of water. This will -greatly simplify the whole process. I~recommend using a level of around 60 -percent hydration. So for every \qty{100}{\gram} of flour use around \qty{60}{\gram} of water. -This ballpark figure will work for most flours. With this hydration, you can -make bread, buns, pizzas, and even baguettes out of the same dough. - -With the lower hydration, dough handling becomes easier and you have more yeast -fermentation, resulting in lower over-fermentation risk. - -\section{What's the best stage to incorporate inclusions (seeds) into the dough?} +\subsection[Incorporating seeds into the dough]{What's the best stage to +incorporate inclusions (seeds) into the dough?} You can include seeds directly at the start when mixing the dough. If you use whole seeds such as wheat or rye kernels, soak them in water overnight and @@ -706,46 +758,3 @@ remains. Adjust your shaping technique a little bit and spread your sugar mixture over a flattened-out dough. You can then roll the dough together, incorporating layers of sugar. -\section{My dough sample (aliquot) doesn't rise. What's wrong?} - -If you see that your dough rises in size but your aliquot doesn't, chances -are that both are fermenting at different speeds. This can often -happen when the temperature in your kitchen changes. The aliquot -is more susceptible to temperature changes than the main dough. -Because the sample is smaller in size, it will heat up or cool down -faster. - -For this reason, you must use room-temperature water when -making your dough. By having the same temperature in both the sample -and your dough, you make sure that both ferment at the same rate. - -If the temperature in your room changes significantly during the day, your -best option is to use a see-through container. Mark the container to properly -measure your dough's size increase. - -Another option could be to use a more expensive pH meter to measure your -dough's acidity buildup. You can read more about different ways of managing -bulk fermentation in Section~\ref{section:bulk-fermentation}. - -\section{What's the best starter feeding ratio?} - -The best starter feeding ratio is commonly either 1:5:5 or 1:10:10. -In the case of 1:5:5 that's 1 part old starter, -5 parts flour and 5 parts water. If you are using a stiff starter, -use half the amount of water. So that's 1:5:2.5. Depending on when -you last fed your starter 1:10:10 might make more sense. If the starter -is old and hasn't been fed recently the 1:10:10 ratio is a better choice. -By reducing the starter inoculation ratio, you provide the microorganisms -with a cleaner environment. This way they can reproduce and regrow -into a more desirable balance to begin your dough fermentation. - -Generally, think of your sourdough starter as a dough. Use the same -ratios you use for your bread dough for your starter. Your starter -should be trained in the same environment that you later use -for your dough. This way your starter is perfectly suited to -ferment the dough into which it is later inoculated. - -The only exception to the 1:5:5 and 1:10:10 rule is the initial -starter set-up stage. For the first days during the starter-making -process there aren't enough microbes yet. So using a 1:1:1 ratio -can speed up the process.