When to pull harvested yeast from fridge?

[cyto]

I am brewing a batch on Monday, today is Saturday. I have been brewing for 25 years but will be using harvested yeast for the first time. I am going to directly pitch the harvested yeast.

Question:
How far ahead of "pitching time" do you take your harvested yeast out of the fridge?

Thanks!

 

[Robert65]

I take mine from the fridge just as many seconds before pitching as it takes me to walk it to the fermenter. While you've no doubt heard that you don't want to pitch warmer yeast into colder wort to avoid "knocking it out," there's no harm in pitching colder yeast into warmer wort. It will wake it right up. Been doing this for a couple of with great results.

 

[BrewInspector]

My general procedure has been to pull out the jar of yeast when I start the brew day allowing it to warm naturally. You should see some activity as the temp rises.

I have recently begun to add some of the first or second runnings from the mash to the jar resulting in more activity.

My goal would be to have the yeast temp as near to the wort temp as possible without any sudden temp boosts in the process.

 

[kh54s10]

I too would say pull it when you start brewing, or maybe part way through, so that it is pretty close to the cooled wort temperature.

I'm not so sure that pouring cold into warm is any less of a shock to the yeast than pouring warm yeast into cold wort.

 

[Vale71]

They're both (warm into cold vs. cold into warm) just as bad, the only difference is that in warm wort the yeast will recover faster. At higher temps everything runs faster and vice versa, so anything will look worse at lower temps than at higher temps. Pastorianus is also slower than cerevisiae even at equally high temperatures, making ale yeast more forgiving of any mishandling.

 

[Robert65]

I only have empirical evidence as to that. I know I can repitch out to dozens of generations and have identical performance with rapid starts and vigorous fermentation. There's no apparent harm. Perhaps it doesn't make a lot of difference how you handle this. There should certainly be no harm in bringing yeast up to wort temperature, but I wouldn't sweat it if for some reason you can't. I suspect the issue of "shock" has been overblown, as I have also learned that I can "crash cool" over a couple of days for lagering, rather than a very gradual step-down in temperature, without sending the yeast into dormancy or experiencing off flavors attributed to shock. I am a lager brewer, but perhaps even within pastorianus some strains are more resilient and my experience atypical.

 

[kh54s10]

I only have empirical evidence as to that. I know I can repitch out to dozens of generations and have identical performance with rapid starts and vigorous fermentation. There's no apparent harm. Perhaps it doesn't make a lot of difference how you handle this. There should certainly be no harm in bringing yeast up to wort temperature, but I wouldn't sweat it if for some reason you can't. I suspect the issue of "shock" has been overblown, as I have also learned that I can "crash cool" over a couple of days for lagering, rather than a very gradual step-down in temperature, without sending the yeast into dormancy or experiencing off flavors attributed to shock. I am a lager brewer, but perhaps even within pastorianus some strains are more resilient and my experience atypical.

Temperature differences shouldn't do too much unless extreme, but I still say close is best.

Crashing and lagering are really 2 different things that pretty much achieve the same primary purpose - to clear the beer. But it doesn't matter it the yeast are sent into dormancy or not. They have already finished fermenting the beer. Some may say there would be a difference between a 2 day cold crash and months of lagering. I don't have the experience to say.

 

[Robert65]

My point there was that I've found that I can simply crash from fermentation temperature to lagering temperature and my lager yeast will happily continue to ferment out at 1°C, if necessary. Yeasties are far tougher and more determined little buggers than they're sometimes given credit for. But particular response to specific temperature programs may still be strain dependent even in lager yeasts and probably quite different in ale yeasts.

 

[cyto]

Thanks everyone. I have a degree in cell biology and chemistry, so I know that thermal shock is real. The question is at what temps and how much.

Real experience is the best guide.

I took it out of the fridge a bit after starting the mash.

 

[9Kegs]

It all depends on the ambient temperature. You will figure it out with doing it a few times and then wonder why you waited so long. I have reused yeast up to 10 generations with no problems. It is convenient and a huge money saver.

 

[Cavpilot2000]

I will typically put the yeast in whatever environment/temp I intend to ferment in (basement floor, fermentaion fridge, etc) at the beginning of brew day to allow it to more gradually rise and adjust to fermentation temp (and no higher). Is it necessary? maybe, maybe not, but there is zero risk and no more hassle than taking the yeast out at any other time, so why not try to make the yeast happy?

The worst thing you could do is big fluctuations, like you're making a lager, but you take the yeast out of the fridge (temp in the 30's) and set it on the counter to warm up (temp in the 70's, say), and then pitch it into chilled wort to ferment (upper 40's). All that up and down could be detrimental.

Pull it from the fridge and put it at fermentation temp, whether that's at the beginning of the day or right before pitching (allowing it to rise in the wort). That way there is only one temp change (almost always warming up to ferm temp).