Why step up fermation temps?

[kingoslo]

Hello,

I have noticed that many recipes suggest to start fermenting at low temps, then gradually increase as fermentation progresses.

What is the reason for this?

Thanks,
Marius

 

[Tonedef131]

It helps the yeast fully attenuate and clean up the mess they made.

 

[kingoslo]

It helps [the yeast] clean up the mess they made.

Yes, the attenuation makes sense, but what does the above mean?


Thank you

Marius

 

[Tonedef131]

Yeast put out a lot of byproducts during fermentation, many of which are undesirable in the final product. So by warming them up near the end of ferment they get more active, this causes them to reabsorb more of these undesirables.

 

[kingoslo]

Thank you!

Marius

 

[david_42]

A chemical called diacetyl (artificial butter-flavor) is the most common 'cleanup', lagers in particular.