chilling wort to 35c, then pitch yeast starter?

[seehuusen]

Hey guys,

Curious what you think about the above?
My water isn't much lower in temp than high 20's and to get the wort to that temp, I'd have to let it chill for hours I'm sure...
I am in the process of making an ice bath recirculation type thing...

Cheers
Martin

 

[mxd]

I wouldn't, but hey that's just me.

I would do nochill then put the cube in the fridge to get it to temp

 

[seehuusen]

I should probably clarify, I used to no chill, but have switched to chilling.
I've got a fermentation fridge, that has taken the wort and pitched yeast from 32c to 22c in about 6 hours...

I guess I could've waited, but is there a good reason to?

And if there's no major drama, is there an upper allowable limit? I guess that may very well be yeast dependent...

 

[Lecterfan]

Yes - there is a good reason to pitch at appropriate temps. I don't know the fancy terms so I'll let you have it in laymans terms. Most - not all - yeasts will produce ******* terrible flavours when brewed over 23-24c give or take. Now, given that the vast majority of yeast-derived flavours occur in the first 12-36 hours of fermentation (coming from the Yeast book and anecdotal experiments...many yeasts pitched healthy and in correct numbers will achieve up to %80 of their attenuation within the first 24-36 hours), pitching yeast at 35c is a fantastic way to make headache inducing fusel-ridden sticky metho. Don't do it.

Or, better yet, try it for yourself and ignore my comments if you like the result.

 

[Mr. No-Tip]

What he said. The lag phase is ultra crucial for flavour development. Pitching at 30 will mean the damage is done when you hit 20. Chill it down in the fridge then pitch.

Or better yet do a double batch and try the two ways side by side. Then you'll know for sure in your own mind.

 

[Phoney]

I've pitched at high 20's, maybe even 30 at a pinch. Then put the fermenter in my chest freezer (fermentation chamber) and chilled it down to 20C within two hours or so. The beers turned out fine, I would probably have had to do a side by side to spot the difference. I'll bet it depends on the style and the yeast as well. A double IPA will mask off flavours to a much bigger extent than others.

Wyeast have said that, paraphrasing: 'Initial pitch can be as high as than 24C' so those temps are definitely pushing it and risking making not great beer. Do whatever you can to avoid it.

 

[Matplat]

Depending on whether you are doing full batch boils...

I pre chill 16ish litres of water in my fermenting fridge, so that when I've got my wort down to 27ish and add it all together in the FV I end up with the right temp to pitch immediately.

 

[Ducatiboy stu]

Dont forget that the higher the temp, the quicker yeast will ferment. By pitching cool we are actually putting the yeast to sleep slightly. Yeast can handle 40*c no problem....but will ferment out in double quick time and make you beer taste far from what it should

 

[Judanero]

:icon_offtopic: When starters are chilled and then decanted prior to pitching into the wort, would there be any increased infection risk by chilling the cube down to say 2c so the starter/yeast is the same temp as the cube and they both rise in temperature together until the yeast becomes active?

Knowing O2 will be more soluble at the lower temp is my main train of thought but unsure if it would increase the risk due to the increased time for yeast to kick off.

 

[QldKev]

What he said. The lag phase is ultra crucial for flavour development. Pitching at 30 will mean the damage is done when you hit 20. Chill it down in the fridge then pitch.

Or better yet do a double batch and try the two ways side by side. Then you'll know for sure in your own mind.

Are you sure about flavors in the lag phase? It's in the log phase. I pitch all my beers warmer to minimise the lag phase. As long as you are at the target temp before the log phase hits you are ok. Pitch warm to minimise the lag phase and minimise chances of other nasties taking hold

 

[superstock]

I pre chill 16ish litres of water in my fermenting fridge, so that when I've got my wort down to 27ish and add it all together in the FV I end up with the right temp to pitch immediately.

^^^^^^^^ I do the same in my lagering/storage fridge @ 5'

 

[seehuusen]

Interesting answers, there seems to be as many opinions as I can think of reasons for and against... Please keep your thoughts coming

I got Krausen going on now, it started forming at just below 20C, 8 hours after pitching.
That, according to How To Brew by John Palmer would suggest I've hit the main fermentation period, would that be considered the log phase?

I'm interested in hearing more about when flavours are developed. I know the later period after the krausen subdues is when the yeast starts to clean up things like diacetyl etc.
In my particular case I'm using a, perhaps slightly over pitched Nottingham Yeast, in a 1.067 SG wort, but I'm guessing the flavours for all yeasts are developed at the same stage? Would that be the case for bottom fermenting yeasts as well?

Cheers
Martin

 

[QldKev]

https://www.wyeastlab.com/he-yeast-fundamentals.cfm

Pitch warm to minimise the lag, but ferment slightly cool if you want minimal esters.

 

[seehuusen]

That was a good read! Thanks Kev

So, by inadvertently overpitching I may not get as much flavour in terms of esters.
Would it be fair to say that 32C is perhaps a bit on the too high side, but circumstances considered I might get away with it?

In the future I should perhaps put the wort in the fermenter and leave that in the fridge until it is at least in the mid-20s?

 

[Mr. No-Tip]

Are you sure about flavors in the lag phase? It's in the log phase. I pitch all my beers warmer to minimise the lag phase. As long as you are at the target temp before the log phase hits you are ok. Pitch warm to minimise the lag phase and minimise chances of other nasties taking hold

Fair point on log rather than lag. "Growth" phase.

Thing is, we don't control or even precisely know when the phases swap. Pitching at 30+ will encourage a quicker ferment overall and quite possibly get yeast multiplying before we get to the temp we should be at, giving esters and fusels and bears - oh my!

 

[mje1980]

:icon_offtopic: When starters are chilled and then decanted prior to pitching into the wort, would there be any increased infection risk by chilling the cube down to say 2c so the starter/yeast is the same temp as the cube and they both rise in temperature together until the yeast becomes active?

Knowing O2 will be more soluble at the lower temp is my main train of thought but unsure if it would increase the risk due to the increased time for yeast to kick off.

I do lagers like this, just not as cold. I'll make a big starter at room temp to grow the yeast. Then when it's done I'll put the starter and th cube in the ferm fridge at 6c. Overnight it'll cool down, then I'll pitch the yeast and then set the fridge to 8-10c. Cleanest most crisp lagers I've ever made are the result.

Ales I try to pitch at 16, then let come up after a day or so.

 

[Dave70]

Just make Saison using 3724 and you'll be good to go.
You can virtually add it at flameout.

 

[QldKev]

That was a good read! Thanks Kev

So, by inadvertently overpitching I may not get as much flavour in terms of esters.
Would it be fair to say that 32C is perhaps a bit on the too high side, but circumstances considered I might get away with it?

In the future I should perhaps put the wort in the fermenter and leave that in the fridge until it is at least in the mid-20s?

Log phase is "several hours" but how many that is we don't know (between 3 and 15). I personally do pitch my no chill cubes at room temp, and up here during summer that may be 30-32c. If you pitch warm, ensure your fridge is powerful enough to know down the temperature pretty fast, and make sure you have a fan in there to assist the airflow. I definitely would not pitch warm without a decent fridge.

Here's another great read, not specifically brewers yeast, but still great reading.
qldkev.net/junk/CPMB.Ch.13.Yeast.pdf

 

[verysupple]

Are you sure about flavors in the lag phase? It's in the log phase.

Yes and no. I'm going to quote a chunk of text from Part Four: Fermentation from the Yeast book here because the authors say it so much better than my first attempt at writing it out. I hope that's not against the rules or anything.

In reference to high temperatures during the lag phase:

While it may not create off-flavors directly, it can increase some precursors, like alpha acetolactate, which is the precursor for diacetyl. If you are going to pitch the yeast warm, be prepared to warm the beer back up to the same temperature or higher near the end of fermentation. This will help the yeast utilize some of these fermentation compounds and will result in a cleaner beer. Other than these precursors, yeast produce minimal flavor compounds during the lag phase. The yeast produce minimal ethanol at this stage, so ester formation is not a concern. Yeast do not create esters until they first make an appreciable amount of alcohols. However, the rapidity of growth during this time will affect flavors later in fermentation. Some brewers begin the lag phase for ales at 72 to 75° F (22 to 24° C), and complete the fermentation at 68° F (20° C). This can be done with success for lagers, too, by starting the lag phase at 72 to 75° F (22 to 24° C) and lowering the fermentation temperature to 50 to 55° F (10 to 13° C).

So my take is that the temperature (among other things, notably nutrient levels) during the lag phase determines the amount of various precursors to flavour compounds. Then during the log phase the yeast produces most of the flavour compounds, of which the amount of each has been determined by the amount of precursors produced in the lag phase. So while the flavours are made during the log phase, the temperature during the lag phase is still very important. Pitching slightly warmer than the desired fermentation temp. can work well, but within reason. I think if it remains up around 30 - 35 C for very long - say, more than a few hours - then that's probably not ideal.

So while the flavours are made during the log phase, the lag phase is still very important.

 

[danestead]

Other than off flavours from pitching warm, if you are chilling rapidly more than a couple of degrees after pitching the yeast, arent you going to stress the yeast out fromthe rapid change in temperature and possibly flocculate into dormancy until they hava acclimatised again?