Yeast's natural fermenting temperature

[trustyrusty]

Question to the yeast experts -

If had a completely insulated area - lets it was 12/15 degrees. ....

Will yeast ferment at is own natural temperature - ie go up to 18/19? I find the yeast working creates a few more degrees than the outside temp. Obviously if no temp. control and it was 30 degrees it would not come down.
I have a brew on at the moment and cannot use temp control. Outside temp is 15, inside fridge is 19, and holding - where I want it. But I feel 19 is where the yeats wants to ferment at - kit yeast. As soon as temp starts dropping most of the work (5 / 6 days) is done.

Thanks

 

[Drubbing]

If your ambient temp is 15, it won't get active if it's an ale yeast. However kit yeasts often work in a wider temp range than branded yeasts, because makers know not every kit brewer has temp control options. But - it's hit and miss as to how often that yeast will be in the active temp zone.

You'd be better off finding a spot where your fermenter is always around 20c or more. Temp fluctuations aren't that big a deal, so long as stays over 18c.

 

[MHB]

Yes yeast will try to ferment at the best temperature for its purposes.

Sadly yeast has no interest in making beer. Its aim is to make more yeast and will do all it can to that end.
We manipulate the yeasts environment, population, nutrients... to persuade it to make the beer we want.
Temperature control is one of the most important flavour controls we can exercise over what yeast does in the brew.
I would recommend getting some sort of good temperature control as being more important than going to all grain brewing, expensive yeast, lots of bling...

If you have a cellar type environment your best choice would be a good neutral flavoured Ale yeast like Nottingham, US05, S-04 among many others are well regarded (most kits are 514 or a blend of 514 and some other yeast).
Lots of ale yeasts will ferment into the low teens, they will produce heat and that warms the environment so they can work faster. There are limits; if it’s too cold when you pitch it may progress very slowly. That increases your chances of getting off flavours and infections.
Mark

 

[trustyrusty]

thanks - I think the kit yeast (in this example, what you added) finds its own natural temp which is around 19.5 -

thanks

 

[trustyrusty]

Yeast is holding at 20 without heater, in fact had to turn temp control to cool on — 15 degrees in room.