I only lagered one time about 5 years ago. At the time, the beer turned out well even though I skipped the diacetyl rest process. As I recall, it took a long time for the primary fermentation to end - two weeks or more. I am using a freezer with a Johnson Controls gauge - it’s keeping it between 50 and 58 degrees Fahrenheit even though it’s supposed to be within 3 degrees. It’s been a week now and everything seems to be okay. SG was 1072 at start and is now 1056. Fermentation seems to be slowing a bit, but it still has a krausen. From my calculation SG should end up between 1021 and 1024 according to the attenuation of Cry Havoc (see White Labs site). Do I go to a diacetyl rest when the krausen falls? Or do I need to measure SG again? What is meant by the krausen falling? Will I be able to see the top of the liquid at that point? I know too many questions, but I’m a bit of a perfectionist. A quirk of my German heritage.
You only need a D-rest if you detect diacetyl. So you have to taste it. If you want to do a D-rest just in case without sampling, then do it when you get 75% of the way to FG. Somewhere around 1.033 in your case. A big lager like that could take 4 weeks or more to ferment.
When the krausen falls, you will be able to see the liquid. But lack of krausen, especially in a lager, doesn’t mean you are completely finished fermenting. Also, attenuation is based on the recipe, not what the yeast says it does. You could mash at high temp, or add a bunch of lactose and only get 20% attenuation or you could add 4lbs of sugar and get 90%.
How do you have your probe hooked up? Is it sampling the air or do you have it secured to the carboy? I put the probe on the carboy and wrap it with an ace bandage to insulate it. I have the analog controller and I have to set it 5 degrees lower than what I want fermentation temp to be.
[quote=“mvsawyer”]
How do you have your probe hooked up? Is it sampling the air or do you have it secured to the carboy? I put the probe on the carboy and wrap it with an ace bandage to insulate it. I have the analog controller and I have to set it 5 degrees lower than what I want fermentation temp to be.[/quote]
Mine is wedged between the brewhauler and the glass, the temp stays pretty constant. I suppose it could be insulated more though…but I don’t bother.
Good Advice.
