diff --git a/README.md b/README.md index b84978b..93985f5 100644 --- a/README.md +++ b/README.md @@ -34,7 +34,7 @@ The book is a work in progress. This represents the current status: * ✅ Microorganisms * ✅ Making a starter * ✅ Sourdough starter types -* ❌ Flour types +* ✅ Flour types * ❌ Bread types * ❌ Wheat sourdough * ❌ Non wheat sourdough diff --git a/book/book.tex b/book/book.tex index db3f30e..5f5c6bf 100644 --- a/book/book.tex +++ b/book/book.tex @@ -71,10 +71,7 @@ \input{sourdough-starter/sourdough-starter-types} \chapter{Flour types} -\section{Wheat like} -\section{Non gluten binding} -\section{Gluten free} -\section{Blending flours} +\input{flour-types/flour-types} \chapter{Bread types} \section{Wheat bread basics} diff --git a/book/flour-types/flour-types.tex b/book/flour-types/flour-types.tex new file mode 100644 index 0000000..00ecf70 --- /dev/null +++ b/book/flour-types/flour-types.tex @@ -0,0 +1,128 @@ +In this chapter we will have a closer look at different flour types +and their respective categorization. We will also look a common +ways to distinguish different flours of the same type. This way you can more confidently +shop the right flour that you need. + +The most basic flour type is a whole flour. In this case the whole seed has +been ground to smaller pieces. Sometimes depending on what you want to bake +the hearty taste of the bran might not be desired. In this case you can use +whiter flours. With sieves mills remove larger parts of the hull of the seed. +The seed already contains a pre built germ from the plant waiting to be +activated. The whitest flour you can get is mostly just the starch part of the seed. +Depending on which layers are still present names are used to describe the +type of flour. + +\begin{table}[htp!] +\centering +\resizebox{\textwidth}{!}{% +\begin{tabular}{|l|l|r|r|r|} +\hline +\textbf{Type USA} & \textbf{Type UK} & \multicolumn{1}{l|}{\textbf{Type Germany}} & \multicolumn{1}{l|}{\textbf{Type France}} & \multicolumn{1}{l|}{\textbf{Type Italy}} \\ \hline +Cake & Soft flour & T405 & T45 & 00 \\ \hline +All purpose & Plain flour & T550 & T55 & 0 \\ \hline + & & T812 & T80 & 1 \\ \hline + & & T1050 & T110 & 2 \\ \hline +Whole & Whole & Vollkorn & T150 & Integrale \\ \hline +\end{tabular}% +} +\caption{\label{tab:flour-types-comparison}A comparison of the different flour types} +\end{table} + +In Germany the ash content is used to describe the flours. The lab will burn +100 grams of flour in the oven. Then afterwards the remaining ash is extracted +and measured. Depending on the quantity the flour is categorized. If the flour +is of type 405 then 405 milligrams of ash have remained after burning the +flour. The more hull parts the flour has the more minerals remain. So the the +higher the number the closer the flour is to whole flour. The numbers are +slightly different between each grain type. Generally though the higher the +value, the heartier the taste is going to be. + +\begin{figure}[!htb] + \includegraphics[width=\textwidth]{wheat-kernel-overview} + \caption{An overview of a wheat kernel together with its content} + \label{fig:wheat-kernel-overview} +\end{figure} + +Several recipes call for wheat bread flour. Bread flour can refer to different types +of flour. It could be a T405 or a T550 in Germany. This is very often +wrongfully classified. The term \textit{strong or bread} flour in this case +refers to the properties of the flour. A bread flour is considered to have a +higher number of protein and thus gluten. This flour is excellent when you +want to make a sourdough bread as your dough allows for a longer leavening +period. As described earlier the gluten is consumed by your microorganisms. +The more gluten you have the longer your dough keeps its integrity. If you wanted +to make a cake you might want to use a flour with less gluten. The gluten binding +properties might not be desirable. The final cake could have a chewy texture. + +In conclusion not every T405, T45 or T00 flour is the same. Depending on the properties +of plant they have different properties. For that reason some countries like +Germany have introduced additional scales to evaluate the quality of the +wheat. The category \textbf{A} refers to good quality wheat that can be blended +with poorer qualities to improve the flour. The category \textbf{B} refers to +average wheat that can be used to create different baked goods. Category \textbf{C} +is used for wheat that has poor baking qualities. This could happen for instance +if the wheat already started to sprout and thus lost some of its desirable +baking properties. This type of wheat is typically used as animal feed or +as fermentable biomass for generators. Category \textbf{E} refers to \textit{Elite} wheat. It's +the highest quality of wheat. This kind of wheat can be harvested when the +wheat has grown under optimal conditions. You can compare this to a winery +that uses only the best grapes to make a reserve wine. Unfortunately this is normally never printed +on the packaging of the flour that you buy. You can look out for the protein +value as a possible indicator. However large mills blend together flours to +maintain quality throughout the years. Blended flour is also not listed on +the packaging. It might be that bakeries extract gluten from some flour and +then mix it in order to create better baking flours. + +In italy the so called +\textbf{W-value} has been introduced to show better how the flour will behave. +A dough is made and then the resistance of this dough to kneading is measured. +The more gluten a flour has the more elastic the dough is and the more it will +resist to kneading. A higher W flour will have a higher gluten content and allow for a longer +fermentation period. But at the same time it is also harder for the microbes to +inflate the dough as there is more balloon material. To make an excellent fermented +product out of a high W flour you will need to have a long fermentation period. +The long fermentation period also means that your microbes will enrich +your dough with more flavor. + +\begin{table}[] + \centering + \resizebox{\textwidth}{!}{% + \begin{tabular}{|l|r|l|r|} + \hline + \textbf{W-Value} & \multicolumn{1}{l|}{\textbf{Hydration in \%}} & \textbf{Uses} & \multicolumn{1}{l|}{\textbf{Fermentation times}} \\ \hline + 0-150 & 50 & Cookies & Very short \\ \hline + 150-250 & 50-60 & Cakes, Bread, Pizza & Short-Medium \\ \hline + 250-350 & 60-70 & Bread, Pizza & Long \\ \hline + 350+ & 70-90 & Bread, Pizza & Very long \\ \hline + \end{tabular}% + } + \caption{\label{tab:w-value}An overview of different levels of W values and the respective hydrations and fermentation times} +\end{table} + + +Generally when aiming to +bake free standing sourdough bread aim for a higher protein content. If the +gluten value is relatively low your bread will collapse faster. Baking bread +is still possible, but it might be easier to use tools such as a loaf pan, or +to make pan bread. + +An additional rarely considered characteristic of good flour is the level of damaging of the +starch molecules. This is a common problem when you are trying to mill your own wheat flours at +home. Chances are that your home mill is not able to achieve the same results +a larger mill can. The damaging of the starches is essential to improve the +properties of the dough. You will have a better gelatinization and water +absorption with properly damaged starch \cite{starch+damage+flour}. As more +starch is damaged the surface area increases. This improves how water connects with the flour. +This also provides a larger surface that your microbes can use to attack the molecules +and start the fermentation process. + +I am still +yet to find a good way of milling my own flour at home. Even after trying to +mill the flour 10 times with short breaks I was not able to achieve the same +properties as with commercially milled flour. The doughs I would make felt +good, maybe a bit coarse. Then during baking however the doughs would start to +degas quickly and turn into very flat breads. I have had great success though when +utilizing home milled flour together with a loaf pan or as a pan bread. If you +have found great ways to work with home milled flour please reach out. The potential +of using home milled flours is huge. It would enable even distant communities +to grow their own wheat and be able to produce amazing freshly baked bread. diff --git a/book/images/external/wheat-kernel-overview.png b/book/images/external/wheat-kernel-overview.png new file mode 100644 index 0000000..4a865bd Binary files /dev/null and b/book/images/external/wheat-kernel-overview.png differ diff --git a/book/references.bib b/book/references.bib index 3ce6f98..ae27a34 100644 --- a/book/references.bib +++ b/book/references.bib @@ -266,3 +266,11 @@ journal = {Applied Microbiology and Biotechnology}, volume = {82,4673-4681} } + +@article{starch+damage+flour, + title = {A review of milling damaged starch: Generation, measurement, functionality and its effect on starch-based food systems}, + author = {Qingfa Wang et al.}, + year = {2020}, + journal = {Food chemistry}, + volume = {15,31} +}