Diastatic Malt & Overproofing
In my last two bakes, I've incorporated a very small amount of diastatic malt flour into my mix. I'm mixing a pretty standard country sourdough mix:
KA patent bread flour, 20% freshly milled whole grain, 80% hydration.
I picked up a bit of 6 row malted barley from a local brewery specialty / supply store and processed it using a Mockmill. I was recommended the 6 row over 2 row, as it contains more protein and would provide more enzymic activity.
I added as little as .002% to my mix (which in the case of 5k of dough, was about 5 grams).
The dough bulk fermented wonderfully in about 5 hours at 75 deg fahrenheit, and had great strength during shaping. However, after getting pulled from the fridge after 12 hours at 36 deg fahrenheit, it appeared to be very over proofed. My fridge is kept at 36-38 degrees, with about 80% humidity.
I'm curious if the issue is related to the malted barley flour, or the temp/time/humidity of my fridge. Has anyone experienced issues with malt flour like this before?