How low does the room temperature have to be to ferment without a fridge?

[TypicalNerveCell]

To make a short question long; I do have a fermentation fridge, but for for me (and many others I assume), fermentation and time for cold crashing is the real bottle neck.

My first 2-3 brews I managed without a fridge, but this was in a very cold room during winter (less than 10C).

My question now is: If I wanted to ferment at 18C, what is the absolutely highest the room temperature could be?

 

[day_trippr]

12°C

I think I would start with the recommended operating temperature range for the yeast strain used, take the high number from that range, subtract 6°C/10°F, and use the result, to cover the peak temperature that the fermentor could reach...

Cheers!

 

[sibelman]

If you can move the beer from the fermentation chamber to a reasonable indoor location after a few days, the chamber will be freed up quickly, and the most temperature-sensitive phase of fermentation will be over.

 

[An Ankoù]

To make a short question long; I do have a fermentation fridge, but for for me (and many others I assume), fermentation and time for cold crashing is the real bottle neck.

My first 2-3 brews I managed without a fridge, but this was in a very cold room during winter (less than 10C).

My question now is: If I wanted to ferment at 18C, what is the absolutely highest the room temperature could be?

I haven't got a fermentation fridge and I've been brewing on and off for over 50 years. I choose my yeast to suit the temperature, but if you want to ferment at 18C for the main part of the fermentation, you need the room to be around 15-16C since fermentation generates its own heat. You also need to make sure that the yeast will continue to work at ambient temperature once the first flush of fermentation is over.
What yeast did you have in mind?

 

[An Ankoù]

Looking at the 14-day weather forecast for Oslo, I'd say now was pretty much ideal.

 

[TypicalNerveCell]

I'm actually quite a bit to the north of Oslo. Last i Checked, the cellar here is 15C, but it might be a little warmer now.
I'm not 100% certain about yeast, but something fitting weissbier.