Summer brewing means warmer tap water, which means that my immersion chiller can only cool the wort to about 75 degrees. I typically cool the wort to 68 degrees before pitching. I have a fermentation chiller that will cool the wort by about one degree per hour.

Would it be better to pitch at the higher temperature, then cool the wort and yeast over the next 8 hours or so, or would it be better to cool the wort to 68 degrees with no yeast, then add the yeast about 8 hours later?

  • Thanks for all the great answers! My main concern was whether or not another bug could take hold in the 8-12 hours that it might take for the wort to cool. I accepted brewchez's answer because it was fairly comprehensive and practical. i.e. I can sleep all night instead of monitoring temperatures in order to pitch at the right time. I wish I could accept two answers, because Denny Conn highlights my main concern with pitching warm: flavor profile. By the way, I will be using this advice this evening, so thanks for the prompt responses! Jul 8, 2011 at 12:35

5 Answers 5


On several occasions I have cooled with my IC the best I could say to 75F in the summer. Then I put the wort in my fermentation fridge until ti gets to 68F or 65F, for example. I usually don't wait for it to happen I just let it go overnight. Then I pitch the next morning. It could be 8-12 hours later. As long as your sanitation is spot on there won't be a problem waiting to pitch if you are still actively trying to cool the wort. Pitching at fermentation temps, or slightly below your desired fermentation temp, is becoming the standard best practice I believe. And it works for me.

Also as the yeast are trying to become active, a drop in temperature tells them that the environment is changing in a way where they might want to become dormant. Some strains are more sensitive to that drop than others. Another reason why its best to pitch at fermentation temp or slightly below it.


The first 72 hours after pitching the yeast are the most critical in terms of flavor development. If the wort is too warm during that period, you can develop off flavors. It is much better to cool the wort before pitching (using your usual excellent sanitation procedures) than to pitch and then cool it down. I have my own sorry experience to back that up!


As long as you are down to ideal fermentation temp within 24hrs, you should be ok. I usually pitch at 78 then move it to a temp controlled freezer, and I have never had any problems.

  • 2
    Usually by 24hrs, the lag phase (yeast multiplying) has completed and you are into active fermentation at that point. So if you aren't at the ideal temp, lots of things can happen: 1. Unwanted esters/ or other off-flavors (banana, sour apple, even bubblegum) can be released 2. The yeast maybe too-stressed, and die, and cause fermentation to end early. #2 is not as likely as #1 since yeast can survive temps into the 100s. I personally have seen beer being fermented commercially at 90s to encourage spicy esters with a saison yeast.
    – baldgeek
    Jul 6, 2011 at 23:38
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    @baldgeek With this in mind, I would want to wait for the wort to cool before pitching. My concern is that during this time some other nasty bug will take hold, since it doesn't have to compete with the yeast. Obviously, good sanitation minimizes this risk, but as homebrewers we aren't sterilizing anything, so there will be some microorganisms other than our yeast in the beer. Jul 7, 2011 at 11:32
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    Downvoted because it's much better for the beer to cool before pitching. Otherwise you can develop off flavors before the beer is down to temp. If your sanitation is as good as ti should be, there's no problem in waiting 24 hours.
    – Denny Conn
    Jul 7, 2011 at 15:47
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    Agree with Denny. Pitching warm by 10-15 degrees and hoping it drops down to temp in time for fermentation kickoff its not ideal.
    – GHP
    Jul 7, 2011 at 15:50
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    You are developing flavors during the lag phase too. You are over concerned about a bug taking hold. Sanitize properly and it will be fine.
    – brewchez
    Jul 7, 2011 at 20:17

My immersion chiller doesn't get me much below 72 in the summer, so I chill it down to whatever temperature I want to get to by immersing the kettle in an ice bath to help things along while the chiller does its part (I have a large "cube" cooler that the kettle fits into very well).

Also, for many yeast strains there are good reasons to get down well below 68 to start fermentation. I recently brewed a Kölsch where the optimal temperature range is around 58-60, and it's important to pitch close to that range if you mean to keep things there for a couple of weeks.

I guess what I'm saying is it depends on the yeast you're using. With strains like US-05 I've never had a problem pitching in the 72-74 range and lowering fermentation to below 68 within a day or so.


Problems with chilling? Then don't chill!

No Chill Brewing for the win!

Seriously. I get great results No Chilling, including with 100% Pilsner Beers. No DMS or off flavors. Those crazy Aussie bastards changed my brew practices permanently.

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