Fermentation Temperature Questions

[jmiller]

2 questions.

1. I have an IPA that I just brewed. Pitched the yeast (liquid White Labs British Ale Yeast). I made a starter that had krausen but never got crazy like I expected. It sat for 3 days. I brewed the IPA, cooled to 70 degrees and pitched the starter in the carboy. It took 48 hours for bubbles in the airlock. This is really odd. It bubbles once every 10-15 seconds which is way slower then anything else I have brewed. I checked the temp an apparently my basement is 56 degrees. Normally it has been 65 with 70 during the really hot months. I have never checked or brewed over the winter before and I failed to think much about it. How will this affect the beer?

2. I want to start brewing Lagers. I have a chest freezer I use as a kegerator with room for a carboy. I keep it at 40 - 44 degrees depending on the swing of the thermostat. Most Lager yeasts look like the optimum fermentation temp is in the low to mid 50's. Will it ferment at 40 and if so what difference does the temp make.

Thanks!

-Jim

[ray m]

I have no experience with lagers so I can't answer Q2. However, regarding your first question:

Don't expect fermentation to have the "swarming bees"/two inches of krausen effect in a starter. Remember, you really aren't giving the yeast a ton of food in a starter anyway---just something to whet their appetite. It is very unusual for yeast prepared in a starter to lag 48 hours. That's a awful long time. This effect may have something to do with your yeast being prepared 3 days ahead of time, and the pretty cold environment in your basement. I would move the fermenter, if possible, to another area of your house that is at least in the mid to high 60's. Also, try only making your starters a day ahead of time, so when you pitch that into your beer, your fermentation will kick off a lot faster because the yeast in the starter will still be doing its thing at pitching time.

[brewmonkey]

I would caution against fermenting in that range if the (lager) yeast does not work in that range. Just like an ale yeast would at low temps a lager yeast will have problems.

If you do get some fermentation at the low temp I would expect an increased lag time as well as fermentation and if the yeast is a known sulfur producer you might also expect to see that increase but it will condition out.