Last week I decided to brew a German Pils using WLP830, just as a cold snap hit our area. Everythign went well with my brew, except that my fermenter is in the garage and it’s so cold my fridge can’t keep the wort above 50. Right now it’s at 48 degrees inside my fridge. The yeast is going, although the lag time was a little long. I’m not sure if I need to do anything to raise the temperature a little. Is 48 degrees too cold to make good beer? I thiink White Labs says the minimum temp for that yeast is 50.
Most yeasts are able to tolerate colder temperatures reasonably well. 48 degrees is only a couple of degrees below the specs. I would think it should be ok just that it will take longer to ferment. It would probably be preferable to bring the temp up by a few degrees, if possible.
Happy Brewing,
Brandon
I went back to my Brewing Classic Styles book by Jamil Zainasheff and John Palmer who (to summarize) suggest cooling your wort to 44F, racking your beer off the cold break (optional, see other posts on this forum), pitching/oygenating and slowly warming the wort to 50F over 36-48 hours. It’s then suggested that the wort is held at 50F for about a week and then put into a secondary to lager as close to 32F for at least 6 weeks.
While this isn’t the most common approach to pitching lager yeast I’ve tried it a couple of times with success. In the end I don’t think you’ll have any issues. Just remember to be patient with a lager beer, but in the end it’s worth it!
As long as the yeast is going then I think you’re fine. It might take a little longer but as long as it’s holding at 48F you should be good to go. I ferment my lagers right at 50F although I haven’t used that strain. I don’t think 2 degrees will make that much of a difference. If it stalls before it’s completely done you can bring it inside for a D-Rest. This is a good experiment 
If the “ambient” temp in your fridge is 48F, your wort/beer could be ~54F. Fermentation generates heat so 6-8F above what you see on your temp gauge, unless you’re looking at a Fermometer or a thermowell temp.
You can always take a thermometer or probe and cover it with insulation like styrofoam and tape it to the side of the fermenator. It should read with in a degree or two of the wort inside.
I like that yeast and always ferment it under 50F. Just remember to pitch enough yeast . Lagers take almost twice as much yeast as ales.
Thanks for the advice…whenever I learn something new about yeast, I’m always amazed how adaptive and flexible those little creatures are!
Build yourself a fermentation chamber. It can be as elaborate as you want or as simple as you can afford. You need a cabinet that is tall enough that you will be able to put a carboy with an air lock on top of it. It would be nice to be able to fit several carboys inside. A cheep kitchen sink cabinet purchased at home depot will work well, or build your own. Put what ever type of counter top you want on it, ie formica or plywood. Pick up a small electric ceramic heater at home depot. Purchase a Ranco Digital Temperature Controller - Wired. The Ranco along with the ceramic heater, will help you control the temperature inside the cabinet when it is too cold in the garage, so that you will be able to maintain the proper temperature range for your lagers and ales. You can also use the Ranco to control a refrigerator or freezer to have a fermentation chamber during the summer. I also use a Ranco to control the temperature for my Keezer. For storing and serving from my cornie kegs.
http://morebeerpro.com/search/102972/beerwinecoffee/coffeewinebeer/Controllers
Ranco Digital Temperature Controller - Wired
FE610
Now you can precisely control the temperature of your fermentation, or a pump…
Read More
Price: $99.95