Cold Pitching Yeast

[pint of lager]

The true answer to so many brewing questions is, "it depends." And often we do not have a good idea as to what guidelines "it depends" on. Often information bleeds down to the homebrewer from commercial brewing, where they have much greater control over ferment temperatures, and can measure and control variables that we as homebrewers do not have access to.

Consider the humble "pitch a truckload of slurry" approach. This may work ok for the slower lagers, but for ales, it can be a recipe for runaway ferments, which may lead to high and excessive ferment temperature.

Clayton Cone's articles are great, and well worth any yeast user/abuser to read. He has about once a year appeared on HBD and answered brewers' questions over a week of digests. Make sure everyone has put Nonicman's link in their favourites, or print out the questions and answers.

Beerisgood is interested in chilling lager yeast starters. I regularly do this. This is my brewday procedure, 45 litre batch size for lagers:

Prior to brewday, I will build up from petri dish to 3-4 litre starter, with small zinc additions and nutrients using og 1.040 starter from cheap supermarket kits.

On brewday, the starter which is actively fermenting is chilled to drop the yeast. Halfway through the sparge I run off about 3-4 litres of wort, boil for 30-45 minutes, chill in the sink, pour the old starter solution off the yeast slurry, pour in the fresh wort, aerate well with a ss stone and continue aerating on and off (excess foam stops me aerating continuously) untill ready to pitch the starter to the fermenter.

Half the wort is run off from the boiler through the CFC, allowed to stand for 10 minutes, then racked off the coldbreak into the fermneter. Starter is pitched and the wort aerated on and off for about 6 hours. The rest of the wort is chilled and collected in a spare fermenter, allowed to chill to air temp, around 5 deg, and next morning, racked into the fermenter with no more oxygenation.

This gives my lagers a good start to ferment. The wort is chilled to fermenting temperature prior to pitching the yeast. Next morning, there is plenty of foam on the surface prior to adding the rest of the wort.

 

[neonmeate]

The rest of the wort is chilled and collected in a spare fermenter, allowed to chill to air temp, around 5 deg,

[post="53022"][/post]​

you must really live in "lagerland" if your air temp is 5C!


sounds like a well organised procedure. i should do that stepping up and aerating with some of the first runnings.

 

[pint of lager]

Depends on the time of year, winter time, the air temp in the evening is always around 3-5 degrees when I do my lagers. During the night in winter it drops to well below zero most of the winter.

The brewday procedure has evolved over the last few years with lots of different variations. This is what I have settled on last winter, and it does work well for my setup..

The other good thing about the way the brewday goes, is that all of the hotbreak and 90% of the cold break is removed from the fermenter prior to pitching the yeast.

Some coldbreak is seen as a good thing in the fermenter. About 10% is what I aim for, based on long time reading of craftbrewer, HBD and the UK digest.

 

[jayse]

I am particularly interested in using this method for starting a lager at lager fermentation temp's and not doing the whole warm start, slow cool, ferment procedure.

[post="53015"][/post]​

Which ever way you go about doing it this is thing you should have in mind of achieving. Not ever having to pitch higher than the fermention temp.
Which ever way you do it your starter should be fine as long as you build up enough yeast. Its better to leave the wort to cool down to ferment temps, while you do this you can take some of it and build your starter up a bit more.

The wort is chilled to fermenting temperature prior to pitching the yeast.

[post="53022"][/post]​

Lager posted some great process tips there and besides needing a new keyboard after typing all that out has some great techniques.
The bit i quoted was a little piece to reinforce that you should whatever way you go about doing it pitch at or below the intended fermention temp.

you must really live in "lagerland" if your air temp is 5C!

[post="53032"][/post]​

I see a new sign on the gate being made right now "Welcome to Lagerland"


Jayse

 

[Kai]

Isn't the temperature shocking always refererred to in the context of going colder (if not explicitly).

Anyway - just because we can't understand something, doesn't mean it won't work. Crikey - yeast was discovered long after beer was being brewed.

[post="52978"][/post]​

True, sosman. I wasn't discounting the idea, just saying I wanted further justification for it. There are plenty of theories bandied about in the homebrewing community, and I'm not inclined to take any of them as true without some supporting basis. I think now we've got that in part with the stuff about trehalose.

As for temperature shock, my impression was (without the inromation about trehalose) that it can go either way, it's just pitching warm to cold is more of an issue because that's more likely to happen in a brewing environment.

 

[Trent]

Hey guys
This may sound like a silly question (maybe alot of mine do ;-)), but after reading what Jayse said about it being better to pitch below ferment temp rather than above, I just wanna know something. I am now brewing in glass carboys, so when I get the wort about as cold as my immersion chiller will take it (around 26C), I drain from the kettle into a plastic bucket, aerate like buggery with a well sanitised electric whisk and stick in my racking cane after about 5L is in there, and rack to my carboy. After about 10L is in my carboy, I chuck the yeast slurry into the plastic bucket, and keep on aerating, thinking I need to take advantage of the aeration while it is there. the ferment fridge brings it down to 18C over the next 12 hours, and then it goes off like a frog in a sock. My last few brews have come out the top of the airlock. My question is, will the aeration be lost if I do all this, put in the fridge to chill to 18, then dump my yeast in when it reaches desired temp? I wanna give my brews all the chance they can have to be top notch. maybe its not even worth worrying about, but it sounds like it could be.
Any info would be appreciated
Trent

 

[jayse]

snipped>
My question is, will the aeration be lost if I do all this, put in the fridge to chill to 18, then dump my yeast in when it reaches desired temp?

[post="53115"][/post]​

Hi trent,
I would aerate the rest of the wort when its at fermention temp, simply not because the air may be lost but because i wouldn't want fresh aerated wort sitting there unless you were to pitch straight away. Reason being the chances of a infection taking hold would increase so for this reason i suggest waiting till its ready to pitch before aerating the rest. As far as 'will it still be aerated?' iam not exactly sure, I would say yes but the chances of a infection making use of the air would be too great.

I leave wort sitting waiting to be pitched all the time but never ever aerated wort.

Hope that helps
Jayse

 

[Hoops]

snipped>
My question is, will the aeration be lost if I do all this, put in the fridge to chill to 18, then dump my yeast in when it reaches desired temp?

[post="53115"][/post]​

Hi trent,
I would aerate the rest of the wort when its at fermention temp, simply not because the air may be lost but because i wouldn't want fresh aerated wort sitting there unless you were to pitch straight away. Reason being the chances of a infection taking hold would increase so for this reason i suggest waiting till its ready to pitch before aerating the rest. As far as 'will it still be aerated?' iam not exactly sure, I would say yes but the chances of a infection making use of the air would be too great.

I leave wort sitting waiting to be pitched all the time but never ever aerated wort. I only aerate the wort no more than an hour before pitching the starter, normally less.

Hoops
Hope that helps
Jayse

[post="53124"][/post]​

Ditto. Imagine if you had a wild yeast in there :excl: it would have perfect conditions to go crazy

 

[Gulf Brewery]

As for temperature shock, my impression was (without the inromation about trehalose) that it can go either way, it's just pitching warm to cold is more of an issue because that's more likely to happen in a brewing environment.

[post="53053"][/post]​

Just found this on the White Labs site (direct quote from )http://www.whitelabs.com/homebrew.html

"Directions for Use- Store in refrigerator until use, do not freeze. Remove 2 hours prior to addition and let warm to room temperature (~70F). This makes re-suspension in the vial easier, and prevents a temperature shock when added to wort. "
Cheers
Pedro

 

[warrenlw63]

Was feeling curious. Yesterday I made 40 litres of Porter and had a slurry from a prevoius batch sitting in the fridge at 4c.

Cooled the wort to 18c via the usual methods. Took the slurry out, poured the old beer off the top and added 1 litre of wort from the kettle. Basically I cold pitched.

Wort only had about 20 mins contact time in the jar with the slurry. Pitched it to the beer after shaking the contents in the jar to evenly distribute.

Results took about 12 hours to reach full krausen.

Last batch was done via the normal stepped up starter. Took about 8 hours to reach full krausen.

Obviously cold pitching works you just have longer lag times.

Warren -

 

[pint of lager]

Depends on how old the slurry was and how much you pitched.

I wish I had a link to post, but don't. From reading, yeast dies off quickly after fermentation finishes. If the slurry is more than a week old, there is a lot of dead yeast.

Mmm, 40 litres of porter.

 

[Boots]

Depends on how old the slurry was and how much you pitched.

I wish I had a link to post, but don't. From reading, yeast dies off quickly after fermentation finishes. If the slurry is more than a week old, there is a lot of dead yeast.

Mmm, 40 litres of porter.

[post="54079"][/post]​

It was in one of the links earlier in the thread. Yeast stored optimally is:

Less than one week at 4 Degrees or less.

Anything longer / worse than that, the yeast aren't considered to be in top shape, so you need to pitch more.

I brewed last night, and cold pitched about a third of the slurry from my last brew. It had been in the fridge for exactly a week at less than 4 deg. Pitched it at 6:30 this morning with the Wort at 18 deg. No action yet at 1pm. Will let you know when it kicks in.

 

[warrenlw63]

Depends on how old the slurry was and how much you pitched.

I wish I had a link to post, but don't. From reading, yeast dies off quickly after fermentation finishes. If the slurry is more than a week old, there is a lot of dead yeast.

Mmm, 40 litres of porter.

[post="54079"][/post]​

Slurry was only 2 days old. I swirled the renmants of my last batch from a glass carboy, flamed the mouth of the carboy and poured it into a 1.5 litre mason jar. Then I just refrigerated it and let it settle.

There was about 5ml of what I'd describe as near enough to pure yeast slurry on the bottom of the mason jar. I just added about a 1 litre of wort from the kettle to the slurry. Shook and let it sit for about 10 mins or so.

POL, sounds like you like Porter ?? :super:

Here's what I whipped up via Jayse's instructions that my Porter needed robusting up, so I modified the grainbill accordingly.

5kg Marris Otter 53.2%
2kg JW Dark Munich 21.3%
700g TF Crystal 120-140EBC 7.4%
700g TF Choc 7.4%
700g TF Amber 7.4%
300g TF Brown 3.2%

45g Target ~10% AAU @60 mins.
20g Amarillo ~7.5 AAU @ 20 mins.
20g Target ~10% AAU @ 5 mins.

Yeast slurry of Wyeast 1056.

Warren -

 

[sosman]

I wonder if I could get my copy signed by Dr Cone ...

 

[Kai]

As for temperature shock, my impression was (without the inromation about trehalose) that it can go either way, it's just pitching warm to cold is more of an issue because that's more likely to happen in a brewing environment.

[post="53053"][/post]​

Just found this on the White Labs site (direct quote from )http://www.whitelabs.com/homebrew.html

"Directions for Use- Store in refrigerator until use, do not freeze. Remove 2 hours prior to addition and let warm to room temperature (~70F). This makes re-suspension in the vial easier, and prevents a temperature shock when added to wort. "
Cheers
Pedro

[post="53227"][/post]​

I guess I wasn't thinking of starters that come right out the fridge, though that does support my point.

 

[Darren]

Hey,
Guys, yeast culture/health should be kept in perspective. At the HB level there are so many variables that change from batch to batch. To say "x" yeast strain started slower after cold pitching when compared to warm pitching the same strain in a slightly different batch is bulls***t.
Just relax. Yeast are tough little buggers. Pitch cold/pitch warm they will carry out their duty in life, ferment sugar and turn it to alcohol and C02.
Any bad/good results you think you got from either warm or cold pitching are pure speculation and I suspect will not stand up to repeated examination..
MO is to pitch as big as you can at the bottom of the recommended fermentation temps and you will have no problems.
To throw another red herring in! I have made more than 100 All-grain batches and have NEVER airated my wort. I pitch then shake the fermenter. Thats it. Never had a stuck ferment either.
Rant off

 

[Boots]

Well, after cold pitching, my batch took 18 - 24 hours to krausen .... but man ... has it got a head on it.

I'm tempted to agree with Darren to a fair degree. My long lag time could be a result of a fair few variables .. and the massive krausen .. well .. this is the first time I've actually pitched slurry, so I imagine I've pitched a lot more yeast than ever before ....

It's a definite possibility that there will be an effect on the end product

 

[warrenlw63]

Same story here Booots,

Got krausen creeping it's way out the airlock. Had to shove a couple of blowoff tubes in. This started about 30 hours after pitching. OTOH This always happens to me with darker worts like Stout or Porter.

I'm in the same camp as Darren. My aeration basically consists of the wort dropping from the outlet hose to the bottom of the fermenter. No more complicated than that.

Warren -

 

[deebee]

I had to have a go at this.

I poured about six litres of boiled cooled water into a freshly racked primary fermenter pasted with 1728 Scottish Ale yeast slurry. I swirled it around to lift the yeast into suspension and whirlpool the hops and break matter into the centre, and after a couple of minutes opened the tap and let the yeast in suspension fall into a fresh fermenter, leaving the muck behind. I got about 4-5 litres of this yeast water and chilled it down to 10C.

Meanwhile, I made a 1.055 wort and chilled it down to about 16C, opened the tap and dropped it into the fermenter with the yeast water. It went into the frig with the thermo on 15C. I didnt get the quick start to fermentation as referred to in the link above as there was only the faintest sign of a krausen when I went to bed 4-5 hours later.

But in the morning it had sprayed the inside of the frig with blowoff from the airlock, it was that vigorous. By the end of the day, the beer had pooled in the top of the fermenter lid and in the bottom of the frig. I had to get the alcohol spray and clean the lot. I have not taken another SG reading but by the look of things, most activity was over in about 48 hours even with the frig set at 15C.

The blowoff was not unaccounted for because
there was a lot of yeast
the wort was well aerated from dropping out of the tap
there was only about 10-15cm of headspace in the fermenter
this yeast does ferment down to 13C.

So like a few have reported in this thread, I found a slightly longer lag time with this technique, but nevertheless very healthy fermentation despite low temperatures.

 

[Snow]

Ok I tried it last night. 1.048 AG Amber Ale, aerated with pump for 30 mins. Slurry from 3L of Whitelabs London Ale fully fermented out and refrigerated for a week. Pitched at 16C and left in the fermenting fridge at 16C overnight. 9 hours later there was some airlock activity, but no huge krausen or anything. Will update after checking tonight.

- Snow