Scalding Milk for Yeast Bread Recipes
We have all seen old yeast bread recipes that use milk with the instruction to “scald the milk” and cool it before adding the milk to the recipe. This is not for the purpose of killing germs.
Milk is already pasteurized by heating in various ways to kill bacteria.
There is an enzyme in the milk called “glutamine” that attacks wheat gluten. It weakens the wheat gluten causing the bread dough not to rise as high as it could and also makes a slacker dough.
The way to prevent this, if you are using milk, buttermilk, sour milk, etc in a bread recipe, is to scald the milk.
Pasteurized milk hasn’t been heated high enough or long enough to deactivate the glutamine enzyme. We have to heat the milk a little more, but not to boiling. That would ruin it.
Heat the milk to 180-F and then allow it to cool to below 90-F before adding it to a yeast bread recipe.
This will deactivate the glutamine enzyme and allow your bread to rise higher and have a firmer dough structure.
Non-fat dry milk also contains the glutamine enzyme and it can also cause your bread to not rise as high and have a slacker dough.
You can buy a special Baker’s non-fat dry milk that has been heated during manufacture to inactivate the glutamine enzyme.
The effects of the glutamine enzyme on bread are small, but there is enough of an effect that bakeries use the special baker’s non-fat dry milk to prevent this.