I have been making wine for many years and am trying beer for the first time. When storing wine for any length of time, the wine must be filled to the top of the carboy to eliminate as much air as possible. This is done to prevent bacteria from forming. As for beer, when placing the beer in the 5 gallon carboy for the secondary fermentation, most likely there will be room at the top. Will this present the same problem that wine makers have or is the process for making beer different. I have read that some leave the beer in the secondary fermenter for two months.
When making beer, you definitely want to minimize the headspace to prevent oxidation if you’re going to transfer to another vessel.
Please note, however, that many brewers feel that such a transfer is not a value added proposition. In fact many argue that the risks (contamination, oxidation, etc.) outweight the benefits, or that there are actually no benefits for a standard gravity beer. I fall in the “no benefits” camp. The only time I would transfer to a “secondary” is if it’s a big beer that requires extended bulk aging. Although my secondary would be a keg, where it will also get dispensed from when the aging period has ended.
If I remember correctly, with wine you “de-gass” it before transferring?
When you siphon the beer from one keg to another, some CO2 will come out of solution. Filling the air space in the carboy.
I’m also in the “no secondary” camp. I’ve had big and small gravity beers sit in a primary for 6-8 weeks with no issues that I or friends can tell.
And one 17% mead sit for 2 years on 2 wine yeast packs and 1 champagne yeast.