diff --git a/book/wheat-sourdough/aliquot-before-after.png b/book/wheat-sourdough/aliquot-before-after.png new file mode 100644 index 0000000..eb481f5 Binary files /dev/null and b/book/wheat-sourdough/aliquot-before-after.png differ diff --git a/book/wheat-sourdough/bulk-finished-dough.jpg b/book/wheat-sourdough/bulk-finished-dough.jpg new file mode 100644 index 0000000..b1139b7 Binary files /dev/null and b/book/wheat-sourdough/bulk-finished-dough.jpg differ diff --git a/book/wheat-sourdough/wheat-sourdough.tex b/book/wheat-sourdough/wheat-sourdough.tex index 37e2167..043d3e1 100644 --- a/book/wheat-sourdough/wheat-sourdough.tex +++ b/book/wheat-sourdough/wheat-sourdough.tex @@ -66,7 +66,7 @@ that tastes much better than any store bought bread. \path [line] (proof) -- (bake); \end{tikzpicture} \caption{The typical process of making a wheat based sourdough bread} - \label{fig:wheat-sourdough-process} + \label{j:wheat-sourdough-process} \end{figure} The whole process of making great sourdough bread starts with @@ -650,6 +650,7 @@ traps the gases during the fermentation process. \cite{how+does+gluten+work}. deteriorates over time as enzymes break down the flour. The effect is accelerated for sourdough due to the bacteria's gluten proteolysis. } + \label{fig:wheat-yeast-sourdough-degradation} \end{figure} % See https://www.figma.com/file/wTUVe6Nm2INOvT82mJhQur/Dough-strength-visualisation?node-id=0%3A1&t=fjdPvXYuJpsdQfWN-1 for % the source of this visualization @@ -718,9 +719,279 @@ However, if the dough is mixed too much, the compounds that contribute to the bread's flavor, aroma, and color may be destroyed, negatively affecting the quality of the bread.\cite{oxidization+dough} +\section{Bulk fermentation} + +After mixing the starter into your dough the next stage of +the process known as bulk fermentation begins. The term +bulk is used because in bakeries multiple loaves are fermented +together in bulk. If you are a home baker you might bulk +ferment a single loaf. The bulk fermentation ends when you +divide and preshape, or directly shape your final loaves or loaf. + +The hardest part when making sourdough bread is controlling +the fermentation process. Bulking long enough but not too +long is the deciding factor for making great bread at home. +Even with poor shaping and baking techniques, you'll be able +to make excellent bread, solely by mastering the bulk +fermentation process. + +With a too-short bulk, your crumb will be +perceived as gummy. Your crumb will feature large pockets of +air commonly referred to as "craters". A too-long fermentation +results in the dough breaking down too much. The resulting +dough will stick to your banneton and spread while baking +into a pancake-like structure. + +The key is to find the sweet spot between not too little +and not too much bulk fermentation. I'd always recommend pushing +the dough more toward a longer fermentation. The +flavor of the resulting bread is better compared to a pale +underfermented dough. + +\begin{table}[!htb] + \small + \begin{tabular}{|l|l|l|l|} + \hline + \textbf{} & \textbf{\begin{tabular}[c]{@{}l@{}}Too short\\ fermentation\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}Too long\\ fermentation\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}Perfect\\ fermentation\end{tabular}} \\ \hline + \textbf{\begin{tabular}[c]{@{}l@{}}Crumb\\ texture\end{tabular}} & \begin{tabular}[c]{@{}l@{}}Unbaked gummy areas\\ towards the bottom of\\ the bread\end{tabular} & \begin{tabular}[c]{@{}l@{}}Crumb can be\\ perceived as\\ gummy, as most\\ gluten broken\\ down\end{tabular} & \begin{tabular}[c]{@{}l@{}}Crumb evenly baked.\\ Crumb can be perceived\\ as moist, but not\\ gummy\end{tabular} \\ \hline + \textbf{Alveoli} & \begin{tabular}[c]{@{}l@{}}Overly large alveoli\\ in the crumb "craters"\end{tabular} & \begin{tabular}[c]{@{}l@{}}Many tiny alveoli\\ equally distributed\end{tabular} & \begin{tabular}[c]{@{}l@{}}Alveoli evenly\\ distributed, no\\ "craters"\end{tabular} \\ \hline + \textbf{Taste} & Pale neutral taste & \begin{tabular}[c]{@{}l@{}}Strong acidic flavor\\ profile. Acidity\\ overweighs when\\ tasting\end{tabular} & \begin{tabular}[c]{@{}l@{}}Balanced flavor profile,\\ not too mild but also\\ not too sour. Depending\\ on starter vinegary\\ or lactic notes\end{tabular} \\ \hline + \textbf{Texture} & Overall poor Texture & \begin{tabular}[c]{@{}l@{}}Good consistency,\\ crumb is not as fluffy\\ as it could be\end{tabular} & \begin{tabular}[c]{@{}l@{}}Great combination of \\ textures\end{tabular} \\ \hline + \textbf{\begin{tabular}[c]{@{}l@{}}Oven\\ spring\end{tabular}} & \begin{tabular}[c]{@{}l@{}}Vertical oven spring,\\ mostly due to water\\ evaporating and\\ inflating the dough\end{tabular} & \begin{tabular}[c]{@{}l@{}}Very flat pancake like \\ structure after baking\end{tabular} & \begin{tabular}[c]{@{}l@{}}Great vertical oven\\ spring. Dough grows\\ more upwards rather\\ than sideways\end{tabular} \\ \hline + \end{tabular} + \caption{The different stages of sourdough fermentation and the effects on crumb, alveoli, texture, and overall taste.} +\end{table} + +The worst thing you can do when fermenting sourdough +is to rely on a recipe's timing suggestions. In 99 percent +of the cases, the timing will not work for you. The writer +of the recipe probably has different flour and a different +sourdough starter with different levels of activity. Furthermore, +the temperature of the fermentation environment might be +different. Just small changes in one parameter result +in a completely different timing schedule. One or two hours +difference results in the dough not fermenting long enough, or +turning it into a gigantic sticky fermented pancake. This +is one of the reasons why the current baking industry prefers +to make solely yeast-based doughs. By removing the bacteria +from the fermentation, the whole process becomes a lot more +predictable. The room for error (as shown in figure \ref{fig:wheat-yeast-sourdough-degradation}) +is much larger. The doughs are perfect to be made in a +machine. + +Experienced bakers will tell you to go by the look and feel of +the dough. While this works if you have made hundreds of loaves, +this is not an option for an inexperienced baker. As +you make more and more dough you will be able to judge +the dough's state by touching it. + +My go-to method for beginners is to use an \textbf{Aliquot jar}. +The aliquot is a sample that you extract from your dough. The +sample is extracted after creating the initial dough strength. +You monitor the aliquot's size increase to judge the +level of fermentation of your main dough. The aliquot +jar is extracted after creating dough strength. As your +dough ferments, so does the content of your aliquot jar. The moment your +sample reached a certain size your main dough is ready +to be shaped and proofed. The size increase you should +aim for depends on the flour you have at hand. A flour +with a higher gluten content can be fermented for a +longer period. Generally, around 80 percent +of your wheat flour's protein is gluten. Check your flour's +packaging to see the protein percentage. The actual size increase +value is highly subjective depending on your flour composition. +I recommend beginning with a size increase of 25 percent and testing +up to 100 percent with subsequent bakes. Then identify a value +that you are happy with. + +\begin{table}[!htb] + \begin{tabular}{|r|r|} + \hline + \multicolumn{1}{|l|}{\textbf{Flour protein content}} & \multicolumn{1}{l|}{\textbf{Relative aliquot size increase}} \\ \hline + 8-10\% & 25\% \\ \hline + 10-12\% & 50\% \\ \hline + 12-15\% & 100\% \\ \hline + \textgreater 15\% & \textgreater 100\% \\ \hline + \end{tabular} + \caption{Reference values for how much size increase to aim for with an aliquot jar depending on the dough's protein content} +\end{table} + +The beauty of the aliquot is that no matter the surrounding +temperature, you will always know when your dough is ready. +While the dough might be ready in 8 hours in summer, it could +easily be 12 hours in winter. You will always ferment your +dough exactly on point. + + +\begin{figure}[!htb] + \includegraphics[width=\textwidth]{aliquot-before-after} + \caption{An aliquot jar to monitor the dough's fermentation progress. + It took 10 hours for the dough to reach a 50 percent size increase.} +\end{figure} + +While the aliquot jar has enabled me to consistently bake +great loaves there are limitations to consider. It's crucial +to use a cylindrical-shaped container to properly judge +the dough's size increase. Furthermore, it is essential +to use room-temperature water when making your dough. If the +water is hotter, your aliquot due to its smaller size +will cool down faster. The aliquot will ferment slower +than your dough. Similarly, when you use too cold water, +your sample will heat up faster than the large dough mass. +In that case, your aliquot is ahead of your main dough. You +would probably stop the fermentation too early. Make sure +to keep the dough and aliquot close together. Some people even +place the aliquot in the same container. This makes sure that +both are in the same environment temperature. The aliquot +is also less reliable if your ambient temperature changes +a lot during the day. In that case, your aliquot will adapt +faster than your main dough. The readings will always be slightly +off. If you are making a large chunk of dough with more +than 10kg of flour the jar is also less reliable. The biochemical +reactions happening inside your dough will heat it. +The fermentation itself is exothermic which means +that it produces heat. + +Another but more expensive option is to use a pH meter +to monitor your dough's fermentation state. As the lactic +and acetic acid bacteria ferment, more acidity is piled +up inside your dough. The acidity value (pH) can be +measured using such a meter. The more acidity the lower the pH +value of your dough. The pH scale is logarithmic meaning +that each digit change will have a 10x increase in acidity. +A sourdough dough might begin fermenting at a pH of 6, +then shortly before baking has a pH of around 4. This means +that the dough itself is 10x times 10x (= 100x) sourer +than at the beginning. By using the meter you can always +judge the state of your dough's acidification and then act +accordingly. + +To use the pH meter successfully you need to find pH values +that work for your dough. Depending on your starter, +water, and flour composition the pH values to look out +for are different. A stronger flour with more gluten +can be fermented for a longer period. To find out +the pH values for your bread I recommend taking +several measurements while making your dough. + +\begin{enumerate} + \item Measure the pH value of your sourdough starter before using it + \item Check the pH after mixing all the ingredients + \item Check the pH before dividing and pre-shaping + \item Check the pH before shaping + \item Check the pH of your dough before and after proofing + \item Check the pH of your bread after baking +\end{enumerate} + +If the bread you made turned out successful with your values +you can use them as a reference for your next batch. If the +bread didn't turn out the way you like, either shorten +the fermentation or extend it a little bit. + +\begin{table}[!htb] + \begin{tabular}{|l|r|} + \hline + \textbf{Step} & \multicolumn{1}{l|}{\textbf{pH Value}} \\ \hline + Starter ready & 4.20 \\ \hline + Mixing & 6.00 \\ \hline + Dividing/preshaping & 4.10 \\ \hline + Shaping & 4.05 \\ \hline + Before proofing & 4.03 \\ \hline + After proofing & 3.80 \\ \hline + After baking & 3.90 \\ \hline + \end{tabular} + \caption{Example pH values for the different breakpoints of my own sourdough process} + \label{table:sample-ph-values} +\end{table} + +The beauty of this method is its reliability. Once you found +out your good working values, you can reproduce +the same level of fermentation with each subsequent dough. +This is especially handy for large-scale bakeries that want +to achieve consistency in each bread. + +While this method is very reliable there are also certain +limitations to consider. + +First of all the pH values that work for me likely won't work for +you. Depending on your own starter's composition of lactic +and acetic acid bacteria your pH values will be different. +You can use the values shown in table \ref{table:sample-ph-values} +as rough ballpark figures. Regardless you need to find values +that work for your setup. + +Another limitation is the price. You will need to purchase +a high-tech pH meter. Ideally, a meter featuring a spearhead. +This way you can directly poke the meter deep into the dough. +At the same time, automated temperature adjustments are a +feature to look out for. Depending on the temperature +the pH value varies. There are tables you can use to +do the adjustment calculations. More expensive meters +have this feature built-in. The pH meter loses accuracy +over time. For this reason, you need to frequently +calibrate this. The process is cumbersome and takes time. +Lastly, you need to carefully rinse the pH meter before +using it in your dough. The liquid surrounding the +head of your pH meter is not food-safe and thus should +not be eaten. I rinse the meter for at least one minute +before using it to measure my dough's fermentation stage. + +The last method to judge the state of bulk fermentation +is to read the signs of your dough. The more bread you are +made the more accustomed you will become to this process. +Look out for the dough's size increase. This can sometimes +be a challenge when your dough is inside a container. +You can help yourself by marking your container. Some bakers +even use a transparent rectangular bulk container. You +can use a pen to mark the initial starting point. From there +on you can nicely observe the size increase. Similar to the +mentioned aliquot jar look out for a size increase that works +for your sourdough composition. + +\begin{figure}[!htb] + \includegraphics[width=\textwidth]{bulk-finished-dough} + \caption{A dough in a good state to finish bulk fermentation. Notice + the tiny bubbles on the dough's surface. They are a sign that the dough + is inflated well enough.} +\end{figure} + +Look out for bubbles on the surface of your dough. They +are a good sign that your dough is inflated with gas. The +further you push the bulk fermentation the more bubbles +will appear. If you overdo this stage the dough becomes leaky and +the bubbles will disappear again. + +Take note of the dough's smell. It should match the same +smell of a ripe starter shortly before collapsing. As mentioned +before, your dough is nothing but a gigantic starter. You +can also proceed and taste your dough. It will taste like +pickled food. Depending on the acidity you can judge how +far the dough is in the fermentation process. The final bread +will taste less sour. That's because a lot of acid evaporates +during baking.\footnote{More on this topic later. +Just by baking longer and/or shorter, you can control +the tang of your final baked bread. The longer +you bake the less sour the final loaf. The shorter +the more acidity is still inside the bread. The resulting +loaf will be sourer.} + +When touching the dough it should feel tacky +on your hands. The dough should also be less sticky +compared to earlier stages. If the dough is overly +sticky you have pushed the fermentation too far. + +If you pushed the bulk fermentation too far you won't be able +to bake a free-standing loaf with the dough anymore. But don't +worry. You can move your dough into a loaf pan, or use parts +of the dough as the starter for your next dough. When using +a loaf pan make sure it's properly greased. You might have +to use a spatula to transfer your dough. Allow the dough +to proof for at least 30 minutes in the loaf pan before +baking it. This makes sure that large cavities induced +by the transfer are evened out. You could push the proofing +stage to 24 hours or even 72 hours. The resulting +bread would feature an excellent very tangy taste. -\section{Controlling fermentation} -This chapter is still pending and will be added soon. \section{Stretch and folds} This chapter is still pending and will be added soon.