WhiteMtnHausBier

Recipes 

Brewed a 5 gallon batch last night (2.5 gal steep then added 2.5 gallons of water to the wort) and racked it into my new 6.5 gal glass carboy, but there is quite a bit of space at the top. Should I add more water to make more use of the space or will the fermentation byproducts need that space to thrive?

Andrewtherooster

Recipes 

You should be fine. It will probably need that space for krausen.

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Primitive Brewing.

WhiteMtnHausBier

Recipes 

Thanks, we had a nice argument last night (after a couple beers no less) over how much space to leave. This was only our second brew and the last one fermented quite violently after 24 hours and the krausen had taken over the entire bottle neck. Is there a term for the space between the krausen and the bottle neck?

badhabit

Recipes 

It's head space, and it looks like it is in primary which means that the air in the space will very soon be filled with CO2 so it is not a problem. Some folks will fill that space with CO2 from a tank if they are using a secondary with that much head space. I have never had a problem but also tend to use a five gal carboy for secondary OR if I use the 6.5 I am dry hopping and giving off enough CO2 in that process that it is not a worry.

strambo

Recipes 

I use an 8 gal bucket for 5 gal batches so I don't have to worry about a mess. The head space quickly fills w/ CO2 anyway.

paraordnance

Recipes 

I once lagered maibock for 4 months with that much headspace. No problems I could detect