Beer Forum

I am just now getting back into home brewing after a 22 year break wife, kids the usual stuff go figure. I have been listening both pod casts and reading about fermentation temps and agree they are important and have no trouble maintaining just about any temp I want in a couple of modified freezers I use to cure homemade dried sausage.

The reason I ask this is 55 degrees at say 20% humidity is not the same at say 60% humidity or even a 55% humidity. Point is it can be 100 in Vegas with 20% humidity and 100 in LA with 40% humidity and I would suppose yeast might be the same way when it comes to relative humidity. The same can be said for a cold dry 32 degrees 10% humidity as opposed to 32 degrees 70% humidity.

So the basic question is how important does humidity play into making beer? I have listened to some say they brew to the season and beers in winter do not turn out the same even if temps are maintained which leads me to think relative humidity does in fact play a role in the process. By default most controlled environments are dry like a refrigerator set up with Johnson controls yet one more step lets me play with the humidity also in the process.

Has anyone played with this in conjunction with temperature control?

IMHO the humidity in a positive pressure container (IE- Carboy/fermentation bucket/other fermenter) is going to be pretty high regardless of the outside humidity. Just set the temp you want and let those yeasties do the work!

Remember- fermentation creates heat- so the temp inside the fermentor may be 5-8 degrees warmer than ambient. I've been meaning to get a thermocoupler inside my carboy, but for now I just duct tape it to the side and its close enough for me!

Welcome, DSB

Assuming you are storing your ingredients in air-tight containers, I think the difference between Summer brewing and Winter brewing for most is

1. the ability to control temps
2. the amount of wild yeast in the air

Rock on,
Push E.

welcome back!!!


as for humidity and yeast....yeast like that 100% humidity that they get when they are in a watery wort. The humidity in the air will only have an effect on the liquid in your air lock OR will have an effect on evaporation when boiling.

Thats not going to affect your fermentation, it will affect your boil off during brewing. You may have to collect less wort or boil longer on a humid day to get the same results on a dry day .. assuming those days were both the same temperature.