I am anxious to start a batch of lambic, but have some reservations timing wise about the temperature in my basement currently. My basement goes from around 45 in winter (now) to 60-65 at the end of summer. If I keep the fermenter at ale temps for the first 10 days or so and then (slowly) lower the temp to ambient, am I going to stall/stunt the wild cultures too much? Would I be better off waiting until the ambient temp is around 60 to let the cultures have a better start before they start to cool off in the winter? Thanks,
I'd try to keep the beer warm for at least two or three weeks to ensure good primary fermentation. If you can do that, I say just go for it. The wild/bacteria portions of the culture will express themselves eventually. Many are slow moving to begin with, and the initial lower temps will not stop them, just slow them down a bit. The beer won't taste right for many months (or years) anyhow, leaving plenty of time for all the beasties to do their things once it warms up.
Plus, it's what the Belgians do. From Jeff Sparrow's Wild Brews (which you should have if you are doing lambics, and don't already):
"A seasonal beer, lambic is brewed and exposed to wild yeast and bacteria while in the coolship and allowed a 'primary fermentation' during the cooler months. The onset of summer brings an increase in the population of lactic acid-producing bacteria. The fall brings with it a secondary alcoholic fermentation by highly attenuative yeasts".