Answer: 48 hours is the longest it should take to start fermenting.
As winter encloses us here in Melbourne, fermentation doesn’t come quite so easily. The cold temperatures will slow down everything your little yeasties do, including waking up and smelling the malt (so to speak). In the warmer months, we’ve had beers start bubbling vigorously within 4 hours, but it’s more normal for it to begin within a day. Now that it’s under 20C regularly, yeast will take a little extra time.
What can you do to make sure they start out quickly? A few things:
- Make sure that after you’ve cooled your beer, it’s close to skin temperature. If it’s frickin’ freezing, it might be worthwhile to put it somewhere warm and cover with a blanket.
- Give your fermenter an extra 30 seconds (or more) of shaking. This makes a big difference. Oxygen is vital for your yeast to snap out of their hibernation.
- Keep your fermenter somewhere warm. I recommend the bedroom or living room, whichever is more consistently warm.
- You could always snuggle with your beer to keep it warm too, however the risk of a spill makes this a risky tactic.
Happy BrewSmithing, and if you have a tips, queries or good ideas, post them up here.