NEIPA and the fermentation temp under pressure

[Plastercast]

Hi all

Second time I have done a brew day and I'm doing a NEIPA. I hit my OG so all good at the end of the brew day. My supposed fermentation temp is 20 deg c but it's been at a steady 28 degrees and as a result the fermentation has been rapid and its gone from 1.058 to 1.029 in 24 hours! As its a NEIPA I'm low pressure fermenting (about 2.5/4 PSI) so I can transfer it into a corney keg which has been pre-flushed with CO2 at the end of the fermentation phase.

Can anyone advise how the high temp, rapid fermentation and low pressure fermentation might effect the taste? The fermentation says 10 days but I think I am going to be done after 5. Is there an issue with racking after 5 days if I hit the 1.008 target OG early?

Next purchase is a fermentation fridge!

Thanks

 

[RoomWithABrew]

Does depend on your yeast really. Kveik would be perhaps cold at 28 and can be fruity which is a feature.
Given your aimed temp of 20 C I'm suspecting a more conventional yeast.
Could up the pressure to 15 psi and that might reduce the ester load, but most are made in the early part of ferment.
Try a wet towel on the fermenter and some bottles of cool water / ice in bottled strapped to side of fermenter.

 

[Agentgonzo]

Try a wet towel on the fermenter

Wet towel/t-shirt paired with a fan (even a small one) do wonders to drop the temperature

 

[MashBag]

Absolutely.
If you have a sealed ice pack, pop it in.

 

[Sadfield]

It is probably fine. The 4 PSI of pressure will likely have more effect on suppressing esters than adding a wet towel.

Pressure increases CO2 in solution.
Lower temperature increases CO2 in solution.
CO2 in solution reduces esters.
They are both ways of reaching the same endpoint. If you're beer comes out carbonated at 4 PSI, then it will have more CO2 in solution than a beer fermented at 20°C with no pressure.

 

[hoppyscotty]

too high fermentation temps can result in off flavours being generated that give fusel alcohol. I have suffered from this and afterward got an old fridge to control temps going forward and it was the single biggest step change improvement in the beers I've produced. You'll have to wait and see if in your case you've been lucky or not.

 

[RoomWithABrew]

CO2 equilibrium is a function of Temperature and pressure.
4 PSI at 28 C has vols of CO2 in solution of 0.74.

This is actually almost the same as the beer at 20 C and atmospheric.

So perhaps no more CO2 in solution than the ferment if at 20C.

However the higher pressure is the factor that suppresses the yeast activity / misbehaviour.

Put some yeast at the bottom of a 300 barrel fermenter and it's being squeezed hard, but not necessarily in a high CO2 environment, especially early in a ferment.
Cool the ferment as best you can, give it time, cross your fingers that you don't have a fusel alcohol bomb and let us know.

 

[Sadfield]

This is actually almost the same as the beer at 20 C and atmospheric.

Exactly, the OP has fermented in a way comparable with a normal atmospheric fermentation. Fusel alcohol and acetaldehyde is also suppressed by pressure.

"The concentrations of esters and fusel alcohols formed during brewery fermentations were significantly reduced by increased carbon dioxide pressure." (Regner, 1992)

Lowering the temperature now whilst at pressure could actually increase diacetyl.