very interesting discussion on primary fermenting in a corny

[Dean]

ironically the gizmo to which i was referring is called a Burton Union   :oops:

[Dean]

and the second google hit is the article i read ...

http://www.byo.com/stories/projects-and ... m-projects

[Kyle]

yeah, I was looking at that Burton thing too. I think next time I ferment in corny kegs, I'll split it into two corneys so there will be no need for a blowoff, just airlocks. I am really liking the idea of moving the beer under pressure from the fermenter to the serving kegs. When I build my eventual basement brewery, I think I'll pick up a couple of sanke's for use as fermenters for the house recipies I know are good. Definately do not want to make 10g batches of experimental beers tho.

[JohnQ]

Impossible to tell if the ferment is faster/slower/same...with nothing coming out of the spund valve except a CONSTANT stream of Hops Aroma embedded in CO2 I can't tell for certain.
I was actually thinking of trying to fashion something to capture the CO2 and divert it through some kind of a water filled airlock so I could measure the burps per minute and get an idea if it's changed in speed.
Given that... the constant hissing would lead me to guess that it would be faster if it's any different.
If my recent idea to test the gravity works, then I'll let you know where the gravity is.

JQ

[Richard]

Vent it into a tall aquarium. Place one tomato plant inside, and one outside. Compare size of plants.

[JohnQ]

I...no... wait... I mean... YOU are a bastard

[Richard]

Ha.

[JohnQ]

Still steady at 6-7 psi, shut it down for a bit to see how quick it builds without the valve, half hour later it's over 10 psi.

Gravity right now (60 hrs) is at 1.035 (OG 1.085).

Interesting Factoid...
From the 89 page thread at HBT, a commercial size fermenter has a pressure at the bottom of the fermenter (hydrostatic) of 7 psi, so even open fermenting would have a pressure on the yeast cake of 7 psi, and obviously a pressure gradient from 0-7 as you go from top to bottom. The corny has hydrostatic pressure of .5 lbs at the bottom, so by adding 5 psi to the top will get you closer to the pressure that the yeast would be under in commercial production, even in open fermentation.

JQ

[Kyle]

cool

[Kyle]

well I transferred the brown ale into a serving keg:

-hooked up liquid line to tap, and ran for about 500ml at 2psi (to get rid of yeast and trub near dip-tube)
- still at 2psi, I hooked up a jumper to another keg and filled

This was an experiment to see if I would need to chop off the bottom inch or so of the diptube on the liquid side to get non-opaque beer. I am very happy to say that while slightly cloudy, the beer is just fine doing it this way. I ordered 5 more kegs for primary fermentation!

[JohnQ]

I moved my competition IIPA across the other day and started 2 more under pressure ferments, one of my version of KyPA and one of the Hoppy Porter.  The natural carbonation from the pressure ferment seems to have finer bubbles if that makes any sense.

Changed the Porter over to Nottingham, and maybe had a bit more than 4.5 gallons....wow, krausen out of the spunding valve.

Now I've put a second keg in the line with some water in it, hooked gas in from primary into liquid out on the buffer keg, then the spunding valve is on the buffer keg.

Now I'm thinking about yeast harvesting from the krausen via the buffer keg.
I'd pre-boil the water going into the buffer keg, sanitize everything and hook it up the same way, seems what I'd end up with at the end of primary is all of the krausen mixed with the water in a sanitized environment, ready to be washed.

Another idea might be to make a 6 gallon recipe, put 4.5 gallons in primary with yeast and 1.5 in buffer keg and allow the krausen yeast to inoculate the buffer keg, do you think that would work?

I've read a bit about harvesting yeast from the krausen, anyone try it?

JQ

[Dean]

since a corny keg is a lot cheaper to come by than a glass carboy i've been thinking about setting a few up for fermentation (albeit NOT under pressure at this time). Are they exactly 5 gallons ...US or imp?

I'm wondering if I can modify them to accept a standard airlock ...and what would happen if there was no airlock at all, what kind of pressure would build?

[Kyle]

they are 5 US gallons, if you don't vent the CO2, at best the yeast will die from too much pressure and at worst the keg will go kaboom.

You can very easily work with a standard airlock, although, I'd use a blow-off hose during active fermentation.

Basicallly remove the gas-in post, take the poppet out, replace the gap with one dip-tube-sized o-ring, and put the post back on, then connect to blow-off hose. If you prefer an airlock, take post off, screw a tight-fitting hose that is about 1.25 inches long over the MFL threads, put air-lock in top of hose, and tighten in place with a hose clamp. Worked very well for me.

[Dean]

hmmmm ..definitely cheaper than carboys then. Unless i'm mistaken, John has CO2 hooked up to his (for a variety of reasons, I know) and that's what is providing his desired pressure in there ....I'm wondering if a pressure relief valve would net the same result?

[Kyle]

I am reluctant to put my faith in the pressure relief valves on the kegs since they are so old, I'm not sure that they will actually still take the 130psi for which they are rated anymore.