2.5 gallon recipe yeast question

[Shonuff]

I want to make a 2.5 gallon recipe. Would one use the same amount of yeast as a 5 gallon recipe (one packet/vial of yeast)? Or would one cut the yeast amount in half.

Would there be any problems fermenting a 2.5 gallon recipe in a 5 gallon carboy?

Thanks for your help!

 

[flowerysong]

Use the same amount of yeast. It's difficult to pitch too much yeast as a homebrewer, and underpitching isn't a good idea.

Fermenting a 2.5 gallon batch in a 5 gallon carboy shouldn't be a problem, but the headspace might prove problematical if you're planning on extended bulk aging.