Add baker's math chapter

This adds the start of the making a starter chapter by introducing
the concept of baker's math

book/book.tex

@@ -7,6 +7,7 @@
 \usepackage{booktabs}
 \usepackage{filecontents}
 \usepackage{longtable}
+\usepackage{float}
 \usepackage[T1]{fontenc}
 \usepackage{tocloft}
 \usepackage[backend=biber]{biblatex}
@@ -63,12 +64,7 @@
 \input{basics/how-sourdough-works}
 
 \chapter{Making a sourdough starter}
-\section{Baker's math}
+\input{sourdough-starter/sourdough-starter}
-\section{The process of making a starter}
-\section{How flour is fermented}
-\section{Determining starter readiness}
-\section{Maintenance}
-\section{Longterm starter storage}
 
 \chapter{Sourdough starter types}
 \section{The regular starter}

book/sourdough-starter/sourdough-starter.tex

@@ -0,0 +1,99 @@
+In this chapter you will learn how to make your
+own sourdough starter. Before doing so you will
+quickly learn about baker's math. Don't worry,
+it's a very simple way how to write recipe in
+a cleaner more scalable way. Once you get the hang
+of it you will want to write every recipe this way.
+You will learn to understand the signs to determine
+your starter's readiness.  Furthermore you will
+also learn how to store your starter for
+long-term storage.
+
+\section{Baker's math}
+
+In a large bakery a determining factor is how
+much flour you have at hand. Based on the amount
+of flour you have you can calculate how many
+breads or buns you can make. To make it easy
+for bakers the quantity of each ingredient
+is calculated as a percentage based on how much flour you have.
+Let me demonstrate this with a small example from
+a pizzeria.  In the morning you check and you realize you
+have around 1 kilogram of flour.
+Your default recipe calls for around 600 grams of water.
+That would be a typical pizza dough, not too dry but
+also not too wet. Then you would be using around 20 grams
+of salt and around 100 grams of sourdough starter.
+\footnote{This is my go to pizza dough recipe. In Napoli
+modern pizzerias would use fresh or dry yeast. However
+traditionally pizza has always been made with sourdough.}
+The next day you suddenly have 1.4 kilograms of flour
+at hand and can thus make more pizza dough. What do you do?
+Do you multiply all the ingredients by 1.4? Yes you could,
+but there is an easier way. This is where baker's math
+comes in handy. Let's look at the default recipe with baker's
+math and then adjust it for the 1.4 kilogram flour quantity.
+
+\begin{table}[H]
+\centering
+\resizebox{\textwidth}{!}{%
+\begin{tabular}{|l|r|r|}
+\hline
+\textbf{Ingredient}    & \multicolumn{1}{l|}{\textbf{Explanation}} & \multicolumn{1}{l|}{\textbf{Explanation}}  \\ \hline
+1000g flour            & 100\%                                     & 1000g of 1000g = 100\%                     \\ \hline
+600g water             & 60\%                                      & 600g of 1000g = 60\%                       \\ \hline
+100g sourdough starter & 10\%                                      & 100g of 1000g = 10\%                       \\ \hline
+20g salt               & 2\%                                       & 20g of 1000g = 2\%                         \\ \hline
+\end{tabular}%
+}
+\end{table}
+
+Note how each of the ingredients is calculated as a percentage
+based on the flour. The 100 percent is the baseline as the absolute
+amount of flour that you have at hand. In this case that's 1000 grams
+(1 kilogram).
+
+Now let's go back to our example and just the flour as we have
+more flour available the next day. As mentioned the next day
+we have 1.4 kilograms at hand (1400 grams).
+
+\begin{table}[H]
+\centering
+\resizebox{\textwidth}{!}{%
+\begin{tabular}{|l|r|r|}
+\hline
+\textbf{Ingredient} & \multicolumn{1}{l|}{\textbf{Baker's math}} & \multicolumn{1}{l|}{\textbf{Calculated value}} \\ \hline
+Flour               & 100\%                                      & 1400*1 = 1400g                                 \\ \hline
+Water               & 60\%                                       & 1400*0.6 = 840g                                \\ \hline
+Sourdough starter   & 10\%                                       & 1400*0.1 = 140g                                \\ \hline
+Salt                & 2\%                                        & 1400*0.02 = 28g                                \\ \hline
+\end{tabular}%
+}
+\end{table}
+
+For each ingredient we calculate the percentage 
+based on the flour available (1400 grams.) So for the water
+we calculate 60 percent based on 1400. Open up your
+calculator and type in 1400 * 0.6 and you have
+the absolute value in grams that you should be using.
+In that case that is 840 grams. Proceed and do the same
+thing for all the other ingredients and you know
+your recipe. 
+
+Let's say you would want to use 50 kilograms of flour 
+the next day. What would you do? You would simply proceed
+and calculate the percentages one more time. I like this
+way of writing recipes a lot. Imagine you wanted to make
+some pasta. You would like to know how much sauce you should
+be making. Now rather than making a recipe just for you, the
+hungry family arrives. You are tasked with making pasta
+for 20 people. How would you calculate the amount of sauce
+you need? You go to the internet and check a recipe and then
+are completely lost when trying to scale it up.
+
+
+\section{The process of making a starter}
+\section{How flour is fermented}
+\section{Determining starter readiness}
+\section{Maintenance}
+\section{Longterm starter storage}