Replace centering by an environment

More LaTeX idomatic

book/bread-types/bread-types.tex

@@ -123,11 +123,12 @@ baking vessels in your oven. To make a freestanding loaf more steps
 and tools are required.
 
 \begin{figure}[!htb]
+\begin{center}
   \includegraphics[width=1.0\textwidth]{free-standing-loaf.jpg}
-  \centering
   \caption{A freestanding sourdough bread. Note the incision known as an
       \emph{ear} and the oven spring clearly
   distinguish this type of bread from flatbread and loaf pan bread.}
+\end{center}
 \end{figure}
 
 Normally you mix your dough. When using wheat you make sure
@@ -196,12 +197,13 @@ warmer it is, the sooner it will be ready. If it is very cold where you live, co
 using warm water.
 
 \begin{figure}[htb!]
+\begin{center}
   \includegraphics[width=1.0\textwidth]{flat-bread-wheat}
-  \centering
   \caption{A flatbread made with purely wheat flour. The dough is drier
   at around 60 percent hydration. The drier dough is a little harder
   to mix. As wheat contains more gluten, the dough puffs up during
   the baking process.}
+\end{center}
 \end{figure}
 
 This way you should have around 11 g of sourdough ready in the evening. You will have
@@ -223,10 +225,11 @@ when getting started. You can observe the dough more easily and see when
 it is ready.
 
 \begin{figure}[htb!]
+\begin{center}
   \includegraphics[width=1.0\textwidth]{ethiopian-woman-checking-bread}
-  \centering
   \caption{An Ethiopian woman baking an \emph{injera} made using teff flour.
   The image has been provided by Charliefleurene via Wikipedia.}
+\end{center}
 \end{figure}
 
 If you used the flatbread option with less water, look at the size increase
@@ -256,11 +259,12 @@ state of my doughs.
 
 
 \begin{figure}[htb!]
+\begin{center}
   \includegraphics[width=1.0\textwidth]{injera-pancake-texture.jpg}
-  \centering
   \caption{A sourdough pancake made with teff flour. The pockets come from
   evaporated water and \ch{CO2} created by the microbes.
   The image has been provided by Lukasz Nowak via Wikipedia.}
+\end{center}
 \end{figure}
 
 If you are feeling lazy or don't have time, you could also use older sourdough starter
@@ -291,12 +295,13 @@ making a flatbread, make the dough around 1 cm thick. When using the pancake
 option, opt for around 0.1--0.5 cm depending on what you like.
 
 \begin{figure}[htb!]
+\begin{center}
   \includegraphics[width=1.0\textwidth]{einkorn-crumb.jpg}
-  \centering
   \caption{The crumb of a flatbread made with einkorn as flour. Einkorn
   is very low in gluten and thus does not trap as much \ch{CO2} as a wheat based
   dough. To make the dough fluffier use more water or consider adding
   more wheat to the mix of your dough.}
+\end{center}
 \end{figure}
 
 After 2--4 minutes flip over the pancake or flatbread. Bake it for the same