New Brunswick Craft Brewers Association

Brewing => Technique => Topic started by: Kyle on August 22, 2011, 07:53:36 PM

Title: very interesting discussion on primary fermenting in a corny
Post by: Kyle on August 22, 2011, 07:53:36 PM
http://www.homebrewtalk.com/f13/primary ... dex13.html (http://www.homebrewtalk.com/f13/primary-fermenting-corny-keg-138178/index13.html)


I've got a brown ale doing primary fermentation in a corny keg. I removed the dip tube for the gas side and I have a blow-off tube attached to that. I did not chop the bottom inch off the liquid dip tube thinking it might work to just push out a pint or two of sludge, and then have relatively clear beer that can be sent to another keg via closed system to remove the rest of the yeast slurry prior to hooking up to serve.

If its too cloudy this way, the next batch, I'll try putting a syphoning foot on the bottom of the dip tube. I like the idea of being able to ferment, transfer, and serve in a relatively closed system.

I've got a fine mesh bag for dry-hopping.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on August 23, 2011, 07:45:54 PM
And more from AHA:
http://www.homebrewersassociation.org/p ... ng-in-kegs (http://www.homebrewersassociation.org/pages/community/videos/show?title=fermenting-in-kegs)
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on August 24, 2011, 10:40:32 PM
John:

How much volume of wort did you put in the keg primary? As an experiment, I filled it right to the top and put a blow-off hose on the gas port (with dip tube removed and extra o-ring as spacer). I've only lost about 3 pints worth, so that should mean I can fill to about 4.5 gallons no problem for round #2.

Also, I found that about 1 and a quarter inch of the silicone hose, with one end clamped to a standard airlock and the other screwed onto the mfl fitting where the gas post lives is a good option.

Did you chop or otherwise modify the liquid dip tube?
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 25, 2011, 08:30:03 AM
Put 4.5 US Gallons.
No mod to the keg, and I'm not using any kind of airlock, only the spunding valve.  I put some CO2 on top to seal up the keg and then let most of it out, now waiting for the pressure to start to build from the ferment. Some time soon I should need to back off on the valve setting.

I'm mostly following the Wiki here with the mods required for the cornies vs sanke...

http://www.homebrewtalk.com/wiki/index.php/Closed-system_pressurized_fermentation

JQ
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 25, 2011, 02:57:37 PM
It's definitely weird not seeing anything happen in front of you, but...
The spunding valve is reading 6 psi and is hissing away nicely.  Must keep a close eye in case the krausen starts shooting out of the valve, but I read somewhere that the pressure actually supresses the krausen.  We shall see!

JQ
Title: Re: very interesting discussion on primary fermenting in a c
Post by: fakr on August 25, 2011, 03:18:14 PM
so John, would you ferment, clarify and serve in 3 separate kegs, or would you transfer to a secondary to clarify and server, just throw out the first couple of cups of sediment?
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 25, 2011, 06:22:21 PM
Most of the stuff I've read suggests 2 kegs is the best, Transfer after ferment is complete to a second keg, capturing the yeast from the first few pints. clarify and serve in 2nd keg.
I don't much care about the clarity of my beer unless it negative affects taste.

JQ
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Jmac00 on August 25, 2011, 09:30:11 PM
might have to try this someday with one of my 10g cornies...thanks for posting.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on August 25, 2011, 09:34:25 PM
where did you find 10gal cornies?
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Jmac00 on August 25, 2011, 09:37:02 PM
one at a yard sale, one on kijiji listed as something else(under the radar i guess you could say)  ;)
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 26, 2011, 09:17:27 AM
Woke up this morning....

Could hear the valve doing it's spunding from across the living room.
Checked and the pressure was at 7 psi, so backed it off a little and now it's down to 6 psi and hissing like crazy!
Must engineer a way to get a gravity sample out of the system without breaching the CO2 barrier.  Maybe replace the pressure relief valve with some kind of dip tube with a tap.  Oh McGyver...I got a job for you.

JQ
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on August 26, 2011, 11:01:57 AM
John, your's is not the same as mine (mine is not under pressure), so we can't call it a real experiment, but have you noticed anecdotally that the fermentation is a bit slower than typical. Of course, I filled the keg to the top and then lost 3 pints to blow-off, so that may have included much of the yeast, meaning there are less of them to work.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Richard on August 26, 2011, 11:37:02 AM
If yours isn't under pressure wouldn't the only difference versus normal be the shape of the vessel? I could understand shape being an issue in large fermentors (it is - from the hydrostatic pressure), but at our scale I don't see it being an issue.

Just my $0.02.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Dean on August 26, 2011, 11:44:47 AM
I read somewhere about a gizmo that cycles the blow-off back into the fermentor ...the article was about a diy small-scale version but there's a brewery aomewhere in the UK that still uses the process. i forget where but the name of the place is also the name of the system
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Richard on August 26, 2011, 12:00:06 PM
burton union kinda does that.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Dean on August 26, 2011, 12:01:35 PM
ironically the gizmo to which i was referring is called a Burton Union   :oops:
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Dean on August 26, 2011, 12:02:24 PM
and the second google hit is the article i read ...

http://www.byo.com/stories/projects-and ... m-projects (http://www.byo.com/stories/projects-and-equipment/article/indices/20-build-it-yourself/354-build-a-burton-union-system-projects)
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on August 26, 2011, 12:37:41 PM
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.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 26, 2011, 05:54:22 PM
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
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Richard on August 26, 2011, 06:01:43 PM
Vent it into a tall aquarium. Place one tomato plant inside, and one outside. Compare size of plants.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 26, 2011, 07:09:11 PM
I...no... wait... I mean... YOU are a bastard
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Richard on August 26, 2011, 07:17:41 PM
Ha. :banana:
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on August 27, 2011, 02:20:01 PM
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
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on August 27, 2011, 10:45:24 PM
cool
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on September 06, 2011, 12:04:37 PM
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!
Title: Re: very interesting discussion on primary fermenting in a c
Post by: JohnQ on September 06, 2011, 07:47:18 PM
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
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Dean on September 07, 2011, 10:26:49 AM
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????
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on September 07, 2011, 10:52:41 AM
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.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Dean on September 07, 2011, 11:38:46 AM
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?
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Kyle on September 07, 2011, 01:07:23 PM
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.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Jmac00 on September 07, 2011, 02:16:43 PM
Quote from: "Dean"
hmmmm ..definitely cheaper than carboys then.


where are you pricing carboys? they can usually be found on kijiji from time to time for avg $10 each for the 6g ones.
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Dean on September 07, 2011, 02:19:34 PM
pricing is a secret ...LOL!   seriously though, you need to be on the members only side of this forum  ;)
Title: Re: very interesting discussion on primary fermenting in a c
Post by: Jmac00 on September 07, 2011, 02:29:30 PM
i c