When is the most critical time to control fermentation temperature?

Question

I know there is a similar question out there, but I am trying to ask for my own particular set u.

If memory serves, I believe that is is in the first 48-72 hours of pitching yeast. This is when they are most active in producing phenols, fusels, esters, etc., and if you want to minimize those, make sure to keep a 'leash' on the yeast by regulating the fermentation temp. I do this with a temperature controller probe insulated with styrofoam, duct-taped to the outside of the fermenter.

I ask the question because I only have room for two vessels in my fermentation chamber/lagering fridge. Currently, I have a California Common in there, and the yeast was pitched Saturday night @ 9pm (pitching + 84 hours at the moment) at 64 degrees.

I have a bit of an aggressive brewing schedule coming up. I am planning on brewing a hoppy american wheat tonight, THEN I am brewing an Oktberfest with my wife on Sunday. Bottom line, I need to have the Oktoberfest set to 50 degrees on Sunday, meaning that the ferm fridge will likely have a lower ambient temp.

My current plan is to brew the wheat tonight (estimated OG of 1.051), pitch a stepped-up US-05 starter (as I need a quick and vigorous fermentation, this wheat is going to be kegged in 12 days) at 66 degrees, then on Sunday (pitching + 4 days), remove the wheat, leave it in the basement (ambient temp of ~74 degrees) to finish up.

The only issue with this plan is that I would need to remove the California Common tonight, as if I tape the probe to the wheat, the freezer will likely get down really low to try to stabilize the fermenter temp AND I would need to do the same with the wheat to make room for the O-fest.

Clear as mud? I'm just trying to minimize unwanted esters, phenols, fusels, etc., and was hoping that I could let these fermentations go after a few days. Alternatively, I could rig up the swamp chiller.

Answer 1

I would say the most critical time to control fermentation temperature, is when most of the fermentation is taking place. US-05 is already a fairly forgiving strain (ferment temp wise). And if you are using a starter, I would bet that you will only be a few points away from FG by the time Sunday hits, given an OG of 1.051.

I think your current brew and ferment plan/schedule you have laid out is a good one.

Answer 2

Not sure if this will help you, but when I run into similar problems with space in my fermentation chiller (a SOFC) I removed the beer at the last possible minute and place it directly into a tote or basin filled with cold water and usually some frozen pop bottles. The water will help to stabilize and slow the temperature changes, even if it is warming up. Adding ice to the water will help you keep the temperature lower, although achieving lagering temps with this method for any period of time is generally impossible. Rubber-made totes that will fit a carboy are dirt cheap. $5-10.