Low Temp Limit for Wild Yeast?
Hamelman says on p 355:
According to Professor Raymond Calvel, "To maintain the viability of the culture, it is necessary to ensure that the temperature of the refrigeration chamber says between 8 and 10 degrees C (46.4 and 50 degrees) whenever the chef is retarded for periods of 48 hours or more. At lower temperatures, part of the flora of the culture may be destroyed....Master Montreal baker James MacGuire adds, "Below 8 degrees C, it is usual for wild yeasts in the culture to be destoryed, while the acetic acid bacteria will continue to thrive.
I keep my refrigerator COLD...the thermometer I have in a warmer part of the fridge says 2 degrees C, maybe 36 degrees F. I'm wondering if this is killing the wild yeast in my sourdough. After I put the loafs into the fridge to proof over night, they never seem to rise again. My commercial yeast products seem to do ok. My mother starter also seems to live, although it doesn't seem as vigorous as it was a few weeks ago.
I questioned that part of Hamelman's book as well. Most fridges are much colder than the minimum cold temps he recommends for storage of the starter and for overnight cold retardation. For safe and efficient food storage your fridge should be just above freezing. Otherwise, you'll notice milk and meat spoilage very rapidly.
I've been overnight retarding outside this winter which is working nicely since most nights we've been down to about 40 degrees but only for a short while. If you look at our temperature it takes awhile to get down to 40 from the 55 degrees or so when we go to bed.
Haven't figured out what I'll do when it warms up, maybe try my wine cooler or something as it has an area where a wine box will fit that we never use.