Too Cold for a Lager?

I have no temperature control, but my garage is well insulated and holds a pretty constant 40-42 degrees all winter long. I made a lager the other day, pitched the yeast into 50 degree wort. 72 hours later it is going, but not strong at all. No krausen, but it there surely is fermentation going on.

I pitched a large 5 liter starter into 10 gallons of 1.045 OG wort. Yeast is wyeast munich lager.

I am wondering if the following protocol will be OK.

Let it ferment cold, very cold until %75 attenuation, this will take weeks at these temps.. Then warm up to 65 (inside my house) for 5 days or so to finish up and reduce diacytel. I am just hoping that my yeast aren't super stressed by the cold. They are working slowly and that is good news.

I would try to heat it to 50 deg. Your starter isn't really large enough for a 10g batch, if it was ale yeast yes, but you need double that for lager IMHO.

onthekeg said:

I would try to heat it to 50 deg. Your starter isn't really large enough for a 10g batch, if it was ale yeast yes, but you need double that for lager IMHO.

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According to mr malty I needed 3.87 liters of starter for this lager.

I got 6.74 liters. Did you switch it to lager? On edit, if you had your starter on a stirplate, you would be okay.

onthekeg said:

I got 6.74 liters. Did you switch it to lager? On edit, if you had your starter on a stirplate, you would be okay.

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O2 start with intermettin shaking.

I see. That shows a 5l so you did it right. I would still try to warm it up a little, but if it keeps chugging along you should be okay bringing it in when it quits for the D rest. I don't think you will need to do a d rest though as you are fermenting cool enough.

onthekeg said:

I see. That shows a 5l so you did it right. I would still try to warm it up a little, but if it keeps chugging along you should be okay bringing it in when it quits for the D rest. I don't think you will need to do a d rest though as you are fermenting cool enough.

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I suppose I could just let her ride cold for 4-5 weeks and see what happens. Thank you so much for your input.

Hey Good Luck! I would guess if you get down around 50% attenuation, you could bring it in if it stalls out and let it go at the warmer temp without an issue.

onthekeg said:

Hey Good Luck! I would guess if you get down around 50% attenuation, you could bring it in if it stalls out and let it go at the warmer temp without an issue.

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This is also a great plan. I will start taking measurements

The lag time was much longer than for an ale or even most lagers. It took 3 days to show any sign of life, and now 6 days later fermentation is really rolling. The wort never went over 45 degrees. It appears as if lager strains can ferment in the low fourties if pitched properly and given time to work.

i wonder what the effects of the ultra cool fermentation is going to be? I am hoping for clean and crisp!

I would leave it alone... if the beer is fermenting, it isn't too cold! Lager yeast+cold ferment= clean beer/good lager. This should be an excellent beer.

45ish is my SOP ferm temp for lagers and have actually gone as low as 35 once, stepping down slowly over a week or so, and still had active ferment. The beer was amazing... it took a long time to ferment at that temp, but that was kind of the point.

I have a lager going at the moment at 42°f. Had a great starter and started the fermentation in my house, at 68°f, then dropped it down in a fridge over a few days. Still lots of activity going on. I have the beer in a fridge that I have at its lowest setting atm. I wish the beer was fermenting a bit warmer, but my garage temp fluctuates about 8-10°f throughout the day and night. My brother has a temp control unit he is going to let me borrow tomorrow. I'm going to try and kick the temp up a bit here starting next week. But I'm wondering how things will be if I just left it as is at the 42°f temp.