diff --git a/book/wheat-sourdough/wheat-sourdough.tex b/book/wheat-sourdough/wheat-sourdough.tex
index e44a3ee..41129c2 100644
--- a/book/wheat-sourdough/wheat-sourdough.tex
+++ b/book/wheat-sourdough/wheat-sourdough.tex
@@ -385,8 +385,9 @@ difficulty.
 
 \section{How much starter?}
 
-Most bakers use around \qty{20}{\percent} sourdough starter based on the dough mass.
-I~recommend going much lower, to around 5 to \qty{10}{\percent}.
+Most bakers use around \qty{20}{\percent} sourdough starter based on the
+flour weight.  I~recommend going much lower,
+to around 5 to \qty{10}{\percent}.
 
 By adjusting the amount of pre-ferment you can influence the time your dough
 requires in the bulk fermentation stage. The more starter you use, the faster