Using a keg as a fermenter

[derekmac]

What would be the issues with using a keg as a fermenter. I understand the advantage of glass in that you can see the product. But everytime you transfer beer (primary to secondary, secondary to keg) you risk oxidizing the beer (the dangers of this are a different thread, I believe, reproduced all over the internet).

I'm thinking that if you put your wort with yeast in a keg and seal it up, it will pressurize itself, and (as long as the pressure doesn't get too high) you can use that pressure to either move the wort into a secondary fermenter (if you're using one) or into the final serving keg. Or, you could serve it directly from the primary fermenting keg.

It just seems to be an easy solution. And if you use Festabrew, and get someone else to clean your keg, it could be the easiest way ever to make beer!

The reason I though of this is because I'm theorizing/configuring a home brewing station using 50l kegs (mash tun and keggle, and perhaps fermenter).

Comments and discussion welcome.

[akr71]

I usually leave a lot of trub and a lot of yeast behind in the primary. That would be my first concern with fermenting and packaging in the same vessel - maybe not so much if I'm brewing up a kit. Leaving the beer on the yeast cake for a prolonged time could cause off flavors from autolysis too, but its nothing that killing the keg quickly couldn't take care of.

[LiverDance]

If you did it all in the same vessell, your first couple of pints would all be trub and yeast. You may get a clogged dip tube doing this but after the first couple I think you'd be in the clear.

[derek]

While I'd agree that you could probably do it, oxidizing is not really a hazard (when kegging) and, in fact, yeast needs oxygen to work. Many (most?) do their primary in an unsealed container (the old-timers used to say to use a 5-gallon pail with a dish-towel over the top. I just leave a loose lid on it. The trick is to get it out of the primary fairly quickly. Then I throw a half-gallon of unfermented wort in the keg, give the open keg a shot of CO2 (so that the syphoned beer from the primary doesn't come into contact with air), and syphon into the keg. Then I let it go to work again to carbonate.

[moxie]

I have seen some very nice and convenient SS set ups with ports for a blow off tube, CO2 transfer, etc, (The best way to do it) but I use the cheap and simple approach:



I suppose I could always pop the spear back in and use CO2 to move it to another vessel after fermentation is complete, but as it stands, I just siphon it to the serving keg after primary, then give the fermenter a good soak in oxyclean -> Iodophor.

If you want to ferment in a Corny keg, you can bend the dip tube a little bit, perhaps a couple of inches off the bottom, then use a keg jumper (2 black QD's) to transfer the clear beer to a serving keg without the risks of oxygen in your finished beer. (You will purge the oxygen out of the new vessel to transfer between kegs.)

[moxie]

Oh, one more thing... If it is all in the same sanke vessel, instead of bending the spear like you would with a corny keg, you can cut a bit off the bottom to pull clean beer, leaving most of the sediment at the bottom. I would still recommend serving out of a different vessel, but I have seen some single vessel brewery designs online, so it can obviously be done!