Small typo fix

book/sourdough-starter/sourdough-starter-types.tex

@@ -222,7 +222,8 @@ around 50 to 60 percent. So for 100 grams of flour you are using around 50 to
   process takes around 3 days. The longer you maintain your starter at the
   suggested hydration level the more adapted your microorganisms become. The
   stiff starter boosts the yeast activity of your sourdough starter.
-  The guide uses 50 percent hydration level. If the dough is too stiff consider increasing this to 60 percent.}
+  The guide uses a 50 percent hydration level for the starter. If the dough is too stiff
+  consider increasing this to 60 percent.}
   \label{fig:stiff-starter-conversion}
 \end{figure}