Attenuation question - fermenting in corny

Question for those who ferment in corny kegs.

The past three beers brewed have been fermented in cornys using fermcap as foam control. Each beer has finished high. Nothing else in my process has changed except using foam control and fermenting in a keg. I pitch a proper amount of yeast - either dry (US-05) or liquid (1028 and Denny's fav.) have been used. Each beer has stopped around 1.02 with an OG of 1.050.

I'm struggling to explain why the yeast are pooping out early.

Any input would be appreciated.

not enough aeration and too much c02?

Not enough aeration - maybe. When I rack from BK, wort goes through a strainer and funnel. There's a bunch of foam on the wort. Looked similar to when I was using buckets. Might have to invest in an O2 canister and rig something up, though.


Too much CO2 - probably not. I put a blowoff on the gas in post. It works like a regular blow-off tube. There's very little, if any, pressure in the keg from off-gassing.

Has anyone else experienced poor attenuation when using a corny as a fermentation vessal?

I'm having a similar problem- I know this thread is crazy old- but were you able to fix this?

Corny's are too narrow to make a good fermenter. You run into problems with fermentation. If I remember it has to do with the limited surface area and the length causes additional pressure on the yeast sitting on the bottom.

But people have fermented in them and some people swear by them. what are they doing that I'm not? I'm confused how some people can do it successfully.

Check out the BrewStrong podcast about fermentors. I believe that's where they go into detail with the issues of using a corny. What exactly makes a corny attractive as a fermentor?

Bigger surface area makes for much happier top-fermenting yeast. There was a study done of hefeweizen breweries but I for the life of me can't find the address. They found long cylinders typically made for unhappy yeast. I also wonder about using fermcaps and knocking down the krausen, when that is where the majority of the work is done by ale yeasts... You could just be stacking too many sub-optimal practices on top of each other to the point where the yeast is going to sleep early.

There's a 14ish page thread on here about the benefits of using cornies as fermenters. Basicaly they work really well for me because I have limited space, can fit a bunch in my fermentation cooler, they're light proof, easy to transport with the handle on there, and I can reduce exposure to air and transfer it from primary/secondary/serving using CO2. I don't use fermcap, I take a poppet off and use a blow off tube. I dont know what I did differently from the others on here that have done it successfully but I've got 15 gallons of like 4% abv beer lol.

just throwing darts in the air.. but maybe your temps are too low?

xxHelderxx said:

There's a 14ish page thread on here about the benefits of using cornies as fermenters.

Click to expand...

I should have asked "Why you do find cornies attractive as a fermenter?".

I have no bias either way and have only really heard why they don't make a good fermenter. Personally I find them to be a pita to clean next to a bucket and carboy.

I think my fermentation temps are fine- I've tweaked them over the course of these last 3 beers to make them slightly warmer because that was one of my first thoughts as well.

I've also heard they can be problematic with attenuation- but the benefits of being able to fit multiple in my ferm chamber and the fact that some people have been very successful made me think to give it a shot.

Has anyone else run into the attenuation problem and corrected it?

I know this is way old but thought it was better to add here then to start a new thread (I hope).

I made a Sweetwater IPA clone 3 weeks ago.

Keg A had yeast I farmed out of a bunch of bottles of Sweetwater IPA, and made a starter.

Keg B, Windsor dry yeast sprinkled straight in.

They BOTH finished at 1.018 (72% attenuation) and BOTH have that Hefeweizen smell.

I used Fermacap drops and a blow off tube but didn't seem to get that strong CO2 smell during fermentation nor did I ever catch it bubbling in the blow off container.

Anyone ever figure out the problem? This is my 5th batch fermenting in kegs (each 10 gallon batch) and this is the first time with this issue.

Here's the recipe.

Sweetwater IPA #110
14-B American IPA
Author: Rob
Date: 10/20/12

Size: 11.0*gal
Efficiency: 88.0%
Attenuation: 72.0%
Calories: 217.07*kcal per 12.0*fl oz

Original Gravity: 1.065 (1.056 - 1.075)
Terminal Gravity: 1.018 (1.010 - 1.018)
Color: 11.0 (6.0 - 15.0)
Alcohol: 6.13% (5.5% - 7.5%)
Bitterness: 64.8 (40.0 - 70.0)

Ingredients:
21.0*lb (92.8%) Pale Ale Malt - added during mash
.75*lb (3.3%) Munich Malt - added during mash
.5*lb (2.2%) Caramel Malt 60L - added during mash
.38*lb (1.7%) Caramel Wheat Malt - added during mash
1*oz (12.5%) Simcoe 11.9 leaf (11.9%) - added first wort, boiled 20*m
1*oz (12.5%) Simcoe 11.9 leaf (11.9%) - added during boil, boiled 60*m
1*oz (12.5%) Simcoe 11.9 leaf (11.9%) - added during boil, boiled 20*m
1*oz (12.5%) Simcoe 11.9 leaf (11.9%) - added during boil, boiled 15*m
1*oz (12.5%) Simcoe 11.9 leaf (11.9%) - added during boil, boiled 10*m
1*oz (12.5%) Simcoe 11.9 leaf (11.9%) - added during boil, boiled 5*m
2.0*oz (25.0%) Simcoe 11.9 leaf (11.9%) - added dry to primary fermenter


Notes
Mashed at 153 for 90 mins. 152.2 after mash.
Keg A - starter from Sweetwater bottles yeast - FG 1.018 has a slight Hef aroma.
Keg B - Windsor Dry yeast. Both ended at 1.018. Both Hef aroma.
11-04-12 Dry hopped, leaf in sanitized reusable hop bag with 5oz's (each keg) of stainless also sanitized. Hung bag inside with lid holding sting to suspend bag into wort below surface.
11-10-12 Kegged. Both have hef aroma and finished high at 1.018

Results generated by BeerTools Pro 1.5.23

I have heard as above, surface area, but cannot confirm. A way to test would be to split a batch, both in cornies, lay one on its side or seriously tilt anyway, and stand on up. One would be tall and narrow, one short and wide.

One common factor here seems to be the use of fermcaps. Why do you feel you need use them?

I use corny's as fermentors, never used fermcaps, and have not had this problem. I rig a blowoff tube on the gas post and let it rip. For very active ferms, karusen will flow out the gas tube just fine.

I went back and reviewed some of my recent brews (beer & mead) and they were very close to the estimated FG (per BeerSmith). I will watch this more closely now, and research, some but for me they seem to working out just fine.

Curtis2010 said:

One common factor here seems to be the use of fermcaps. Why do you feel you need use them?

I use corny's as fermentors, never used fermcaps, and have not had this problem. I rig a blowoff tube on the gas post and let it rip. For very active ferms, karusen will flow out the gas tube just fine.

I went back and reviewed some of my recent brews (beer & mead) and they were very close to the estimated FG (per BeerSmith). I will watch this more closely now, and research, some but for me they seem to working out just fine.

Click to expand...

I brew 10 gallons finished to the fermenter. This is pretty close to the top of the keg before fermentation begins. Others have mentioned in the Foam Control Drops thread that they do not have off flavors or problems attenuating.

I am curious as to why I have had zero problems on 8 other kegs fermenting and now with this one a problem. Some were baby gas drops from the local drug store while others fermacap (about half i would guess).

I have experienced stuck fermentation before and also the Hef flavor/aroma . I thought it was going to be from farming and reusing the yeast from the original Sweetwater IPA but when the Windsor yeast had it too, I was stumped. Obviously the common factor as you mentioned is the drops.

When you ferment in kegs without the drops:

A) how close to the top in inches do you fill?
B) do you remove the poppet from the gas post?

I fill right to the weld, which is right at 5 gallons I believe.
If I'm not pressure fermenting, I'll take the whole post/tube setup off and put a 1/2" blowoff on the threads of the post with a bandclamp to keep it in place.

I've only had off flavors once: a saison got lacto'd due to poor sanitation in my opinion. Luckily friends and family thought it was the second coming of Jesus, but I learned my lesson.

EVERY keg (especially my fermentor kegs), gets completly broken down and put on the keg washer for hot PBW (with inspection, hand scrubbing, and rewash if necessary), hot clean water rinse, then starsan that's pushed out by co2, and the keg is stored at 30 psi.

Hugh_Jass said:

Has anyone else experienced poor attenuation when using a corny as a fermentation vessal?

Click to expand...

No problem here.

Denny said:

No problem here.

Click to expand...

Denny, are you using any foam control?

I'm same as Curtis2010, just put connect a blow off tube to the gas out connector.

I used the corny as a fermentor for my lagers because of space in my keezer. I've never had a problem with under attenuation. My last batch I noticed that the fully fermented beer was lightly carbonated. I attribute this to the long 1/4 blow off tube (more restriction compared to air lock)

Most beers are only 4.5 to 4.75 gallons so there is a little head space. The other aspect is lagers produce a smaller, tighter krausen. So in reality, I've never needed a blow off tube.

Yambor44 said:

Denny, are you using any foam control?

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Yeah, usually. No difference using it or not, other than foam.

Yambor44 said:

When you ferment in kegs without the drops:

A) how close to the top in inches do you fill?
B) do you remove the poppet from the gas post?

Click to expand...

I fill 10 gal. cornies to about 8 gal. and 5 gal. cornies to about 4-4.5 gal. I don't remove the poppets, posts or anything else.

Denny said:

I fill 10 gal. cornies to about 8 gal. and 5 gal. cornies to about 4-4.5 gal. I don't remove the poppets, posts or anything else.

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Sorry for all of the questions Denny, I assume you just use a blow off? Also, when you transfer from OUT to OUT do you leave the poppets in then as well?

My first batch doing that went fine. My second batch plugged up (probably from hop debris) so I started removing the poppets from each keg post as well as the guts from the black QD's.

Thanks.

Yambor44 said:

Sorry for all of the questions Denny, I assume you just use a blow off? Also, when you transfer from OUT to OUT do you leave the poppets in then as well?

My first batch doing that went fine. My second batch plugged up (probably from hop debris) so I started removing the poppets from each keg post as well as the guts from the black QD's.

Thanks.

Click to expand...

No problem! Yep, I use a blow off although I seldom actually get blow off. I use a blow off in every batch, regardless of fermenter type. I'd rather have it in place if needed than discover too late that I should have!

Yep, I leave the poppets in the xfer. I did have a problem once, but I simply removed the post, cleaned and sanitized it, and rteplaced it.

Thanks everyone. I am going to leave things "as is" and chalk this weird flavor up to something else.

I'll post back here as well as the other "hef thread" if I ever figure it out.

Rob

Yambor44 said:

... Some were baby gas drops from the local drug store....

A) how close to the top in inches do you fill?
B) do you remove the poppet from the gas post?

Click to expand...

Oh man, baby gas drops ....whether or not that caused problems with ferm, I would never be able to get that image out of my head! Batch would be ruined for me and I would have trouble keeping a straight face when friends drank it!

I fill to about the weld (mas o menos) depending upon the exact batch size. Remember the gas tube sticks down in the keg just slightly so if you over fill some liquid will get pushed out the blow off tube (voice of experience).

With a very active ferm I route the tube out of the keezer and into a bucket so I don't make a huge mess in the keezer.

I normally don't remove the poppet and it has not caused me problems. I do sometimes if more solids than usual ended up on the keg. But either way, it has never caused me a problem. Even if the poppet did get clogged you ultimately have the over pressure valve, but you might over-carbonate your beer at those pressures.

Well, well, well! Just tapped the beer recipe from above Keg A (the Sweetwater harvested yeast) and the hef smell and taste....gone! Taste and looks like the real deal to me!

I am very glad.

I guess somehow it cleaned up while under CO2 carbonation for 5 days (30 PSI at 65F ambient).

Thanks again for everyone's help.

Yambor44 said:

Well, well, well! Just tapped the beer recipe from above Keg A (the Sweetwater harvested yeast) and the hef smell and taste....gone! Taste and looks like the real deal to me!

I am very glad.

I guess somehow it cleaned up while under CO2 carbonation for 5 days (30 PSI at 65F ambient).

Thanks again for everyone's help.

Click to expand...

Great! Maybe the combination of more time on the yeast and some carbonation helped clear it up.

I've managed to clean up a couple of brews by "scrubbing" them with CO2 (carbonate, off-gas, carbonate....repeat a few times). Works for some off-flavors. Rescued a Bitter last season that way.

Good to know for future reference Curtis. Thanks!