Blue Cheese and Protease Attack
A friend experienced what appeared to be a protease attack earlier this week while making a Blue Cheese, Walnut, and Fig sourdough using the Tartine approach. The loaves began normally - up to forming and then sat with little change. Rather interestingly this was done in parallel with a batch a Tartine aux Cereales using the same sourdough starter and dough recipe. The loaves without blue cheese performed admirably. My friend told described the problem to me and wondered what about the blue cheese might have led to the problem.
Suspecting protease failure, I Googled blue cheese and found that much if not most blue cheese has protease added during its manufacture. As a result the Blue Cheese loaves would have a higher level of protease than the regular dough. Cool winter kitchen temperatures mean longer fermentation and proofing times but as I understand it enzyme activity is much less temperature sensitive than the yeast. This apparently allowed the protease to destroy the gluten before the yeast could finish and the bread be bakes.
I wanted to document this because the TFL site has recorded many successful efforts to use blue cheese in sourdough. In looking at other recipes using blue cheese it is interesting that most that I can find that use blue cheese IN the bread use ADY or IDY rather than sourdough. Others form the bread. slash it, and insert the blue cheese in the slash. Others put it on top. Peter Reinhart is one of the few who suggest putting the blue cheese IN the loaf and he says to do it in the last two minutes of kneading. Apparently that minimizes the spread of the cheese protease in the dough.
It appears that mixing the blue cheese in early or having a long proofing time (low temps or low yeast activity) with blue cheese breads is a potential source of problems.