Chapter Hooch + Acetone

Add chapter about a liquid gathering and an acetone smell
from your sourdough.

book/references.bib

@@ -58,7 +58,7 @@
   note         = {Accessed: 2022-04-29}
 }
 
-@article{food-safe-ph,
+@article{food+safe+ph,
   title        = {Acidified Foods: Food Safety Considerations for Food Processors},
   author       = {Felix H. Barron and Angela M. Fraser},
   howpublished = {\url{https://www.intechopen.com/chapters/41654}},
@@ -75,3 +75,17 @@
   year      = {2022}
 }
 
+@article{liquid+on+starter,
+  title        = {Acidified Foods: Food Safety Considerations for Food Processors},
+  author       = {Sourdoughhome},
+  howpublished = {\url{https://www.sourdoughhome.com/what-is-hooch/}},
+  year         = {2020},
+  note         = {Accessed: 2022-04-29}
+}
+
+@article{acetic+acid+production,
+  title        = {Acetic Acid (or Ethanoic acid). The main constituent of vinegar.},
+  author       = {chm.bris.ac.uk},
+  howpublished = {\url{http://www.chm.bris.ac.uk/motm/acetic-acid/acetic-acidjs.htm}},
+  note         = {Accessed: 2022-04-29}
+}

book/troubleshooting/crumb-structures/crumb-structures.tex

@@ -67,6 +67,7 @@ style of crumb. As someone who appreciates jam, no jam will fall through a slice
 of this bread compared to an open crumb.
 
 \subsection{Overfermented}
+\label{sec:overfermented-dough}
 
 \begin{figure}
   \includegraphics[width=\textwidth]{fermented-too-long}

book/troubleshooting/misc.tex

@@ -63,7 +63,6 @@ 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}
-\label{sec:flat-bread-crumb}
 
 A flat bread is in most cases related to your gluten
 network breaking down fully. This is not bad, this
@@ -96,7 +95,7 @@ the yeast part of your starter. This allows you
 to have less bacterial fermentation, resulting
 in a stronger gluten network towards the end
 of the fermentation \cite{stiff+starter}. Please
-also refer to the section ~\ref{sec:flat-bread-crumb} where
+also refer to the section ~\ref{sec:overfermented-dough} where
 I explained more about overfermented doughs.
 
 \begin{figure}[!htb]
@@ -228,7 +227,7 @@ 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
+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.
 
@@ -287,7 +286,111 @@ to a hydration of 100 percent the mold should have been eliminated. Please note
 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 after shaping}
+\section{My bread flattens out 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
+relaxes and can no longer hold the shape. However, during the course
+of baking your dough is going to increase in size and inflate again.
+
+If your dough however flattens out completely it's a sign that
+you have fermented your dough for too long. Please refer to ~\ref{sec:overfermented-dough}
+where I explain about overfermented doughs. Your bacteria
+has consumed most of your gluten network. That's why your
+dough fully collapses and stays flat during the bake. The
+CO2 and evaporating water will diffuse out of the dough.
+A related symptom is that your dough sticks to the banneton.
+When starting baking I combatted this with rice flour.
+It works but might be a false friend. I gently rub my
+dough with a bit of non-rice flour before placing it in
+the banneton. Now then the dough starts to stick to the banneton
+while I remove it I resort to a drastic measure. I immediately
+grease a loaf pan and directly place the dough inside. The loaf
+pan provides a barrier and the dough can't flatten out as much.
+The dough won't be as fluffy but super delicious if you love tangy bread.
+
+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 removing it from the banneton}
+
+Similarly to a dough flattening out after removing it from the banneton,
+a flattened dough after shaping is also a possible sign of overfermentation.
+
+When you try to shape the dough, can you easily tear pieces from the dough?
+If yes, you have definitely overfermented your dough. If not it might just
+be a sign that you have not created enough dough strength for your dough.
+A ciabatta for instance is a dough that tends to flatten out a bit after shaping.
+
+If your dough is not possible to be shaped at all use a greased loaf pan
+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}
-\section{Why does my starter smell like acetone}
+
+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 {\it 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]
+  \centering
+  \includegraphics[width=0.5\textwidth]{hooch}
+  \caption{Hooch building on top of a sourdough starter. \cite{liquid+on+starter}}
+  \label{fig:hooch}
+\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 setup 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]
+  \centering
+  \includegraphics[width=1.0\textwidth]{ethanol-oxidation}
+  \caption{Oxygen is required to create acetic acid \cite{acetic+acid+production}.}
+  \label{fig:ethanol-oxidation}
+\end{figure}
+
+This is nothing bad. But in case 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}