I pitched the yeast at 40°F (4.5°C). Was it way too cold and should I re-pitch?

  • 1
    Can you give more details - what kind of yeast was it? Did it come with the kit, any instructions regarding temperature?
    – mdma
    Commented Nov 20, 2013 at 8:27

2 Answers 2


I assume you mean 40°F, then yes way too cold. it won't harm the existing yeast organisms, but even for lager yeast that is too cold for primary fermentation.

so basically we do things at certain temps for a reason... we try to pitch yeast at a temperature that gives them the advantage over other contaminant organisms.

warm your wort to the primary temperature and fermentation should start after a short delay.

  • 1
    I would note after warming it should be mixed again as the yeast should all go into hibernation from being that cold if is ale yeast.
    – Kortuk
    Commented Nov 20, 2013 at 15:20

I assume you mean Fahrenheit and are brewing an ale, not lager. Yes- that is way too cold. Most ales are best pitched around 75°F (24°C), although I've yet to have a problem with temperatures up to 100°F (37°C).

For best results use a wort chiller to chill the wort as rapidly as possible. The longer the cooling time, the greater the chance of contamination. Additionally, a yeast starter is always a good idea.

  • 75 is pretty high, even for an ale. You'll make a cleaner beer fermenting at a temperature closer to the bottom of the yeast's recommended range. Commented Dec 21, 2013 at 16:26
  • White Lab's California Ale yeast, which is MoreBeer's #1 selling yeast , says on the label to pitch at 70-75. Same for their Irish and London Yeast. Commented Dec 21, 2013 at 16:53
  • If you pitch at 75, once fermentation starts the temperature will rise due to the heat produced by yeast metabolism, taking it outside the recommended range. Pitching at a low temperature, and maintaing a low temperature throughout the fermentation produces a beer with fewer esters and fusel alcohols, i.e. a cleaner tasting beer. Commented Dec 21, 2013 at 18:23

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