Temp/flavor Relationships

[Koikaze]

Hey guys,

I was reading a few threads and i began to wonder what difference in flavor the temp makes. I know that too hot produces esters and a cidery taste (from a horrible experence) but what kind of taste difference does a beer fermemted too cold produce?

And for conditioning? what difference does the temp make to the flavors during this phase?

 

[Adamt]

Easiest analogy to answer this question is... at lower temperatures the yeast is more relaxed and does what it does best, convert maltose/other sugars into alcohol and carbon dioxide. As the temperature increases the reactions producing esters, acetaldehyde, etc become more possible. If the temperature is too cold the yeast won't do anything.

As far as conditioning goes there isn't a huge amount of yeast activity here but flocculation/sedimentation of the yeast will be favoured by lower temperatures.

 

[maltedhopalong]

IMO the colder the better. There are two exceptions:

1. If the particular style you're after calls for lots of esters, too cold might make these characteristics too subtle but generally the yeast and fermentables profile that you use will be tailored to provide the right amount of fruitiness/floralness/whatever.
2. If you brew too cold, the yeast may go to sleep and you may run into problems getting it to ferment.

Edit: Check this thread out tho: http://www.aussiehomebrewer.com/forum/inde...showtopic=20732
Not sure what to make of it, can't understand how a yeast strain could be trained to produce LESS esters when it's at a higher temperature. Higher temperatures = higher energy, that extra energy is what allows more different chemical reactions which allows the yeast to metabolise more different sugars which creates more different chemicals (acetaldehyde, esters, etc.).

Then again, it's still worth a read, take in more knowledge and make your own decision.

 

[DJR]

Colder with some strains can also mean sulfur and diacetyl (buttery flavour) production. The sulfur can occur because of yeast stress, but some strains just do it anyway. Can be quite pongy the first time it happens, but it will dissipate with age. Diacetyl is due to yeast metabolism, but it can be cleaned up by raising the temperature after the cold ferment to allow the yeast to metabolise the diacetyl.

 

[petesbrew]

Just poked my head in the garage to put back another empty longneck and saw my garage temp was 13degrees.

HELLOOOOOO WINTER!

Got a lager yeast in the barfridge I'm hanging to pitch!

(Although i'm pretty sure the temps are gonna fluctuate till winter really hits)

 

[the_purple_dragon]

Just poked my head in the garage to put back another empty longneck and saw my garage temp was 13degrees.

HELLOOOOOO WINTER!

Got a lager yeast in the barfridge I'm hanging to pitch!

(Although i'm pretty sure the temps are gonna fluctuate till winter really hits)

I've had an esky with rotating ice block going in my garage (Brisbane) for the last couple of days and had the temp steady at about 22 - 24 deg, being the ambient have been between 18 - 31 deg. And last nite we had a cold snap so the esky dropped to 16 deg. I'm hoping the drop wont affect my brew....

 

[rimrunner]

the flavours and esters produced by yeasts vary depending on the yeast as well.

i'm sure you didn't really want to know that though.