Repeated off flavour.

[Skillz]

Hello all.
I have had a rough time trying to figure out an off sweet taste I keep getting.
I have started using a chubby fermenter and purging a keg with the co2 produced from fermentation as well as putting .3g of potassium metabisulfite in the keg being purged.
The left over beer in the chubby taste bright Clean and just what I want even after another week but i just poured the first pint off the keg after a week of carbing and it is sweet and muted in flavour.
I have had this in pales and Ipa's.

Oxidation is my guess but I am putting a fair bit of effort into mitigating this.
The next line of thought is a persistent house infection in the kegs or lines.
I should clarify I used brand new transfer lines on this beer.
I soak my kegs in sodium percarbonate after it kicks and then rinse dry and store, when I need it I put a few litres of boiling water through it and then sanitise.

Any ideas

 

[An Ankoù]

Sounds as if you've got the sanitation and oxidation things under control. Here's a thought: you say you transfer your beer when it's clean and bright, but why not transfer it when it's coming to the end of the fermentation and still a bit cloudy, and also prime the keg with a couple of tablespoons of sugar- it should take the beer about three days to eat that up- that way, your beer is still saturated with carbon dioxide and less likely to be affected by oxygen. I used to do that with plastic pressure barrels and I never had a problem. These days I bottle everything and I've found that some yeasts are just not suited to bottling. Changing your yeast might do it, but at the end of the day, it's a matter of trial and error.
If your lines are at least "clean" then any infection wouldn't have time to affect the beer from pouring to drinking, would it?

 

[Skillz]

Sorry I ment the beer taste is clean and vibrant from the fermenter, I transfer after a 2 or 3 day cold crash at 1c.
I also do a closed loop transfer and make sure I purge the lines of oxygen before transfer.

 

[An Ankoù]

Sorry I ment the beer taste is clean and vibrant from the fermenter, I transfer after a 2 or 3 day cold crash at 1c.
I also do a closed loop transfer and make sure I purge the lines of oxygen before transfer.

Just a thought. You mention metabisulphite and percarbonate. If you do the final rinse of keg with percarbonate before putting the beer in, you'll get some oxidation as the percarbonate produces hydrogen peroxide and oxygen. But if your final rinse is with metabisulphite and then well drained, you should be ok as it works as an antioxidant.

 

[Skillz]

I soak the keg in percarbonate and the rinse well.
Then on brew day I rinse with boiling water and put .3g of potassium metabisulfite in the bottom as an added oxygenation measure.
I then hook the gas out from the fermenter to the liquid side of the keg and let the fermentation hopefully push all the o2 out over the next few days.
Then build preasure to 10psi in both and cold crash to allow extra o2 absorption from the keg so no suck back or cave in.
Keg should be as close to o2 free as possible and still has the .3g of potassium metabisulfite in it to scrub any oxygen that did hang around.

The difference between drinking from the keg and the fermenter is day and night.

The keg was not hooked up to my tap line while conditioning so can't be an Infection from that end.
It has to be in the keg, I really feel like it's an oxidation thing but don't see how it can be.

 

[An Ankoù]

I'm at a loss, mate. Sorry.
Sounds as if you're doing everything you should and more!

 

[Grok]

What about the gas lines, maybe an infection residing in there?

 

[Skillz]

What about the gas lines, maybe an infection residing in there?

This could be one place I need to look at

 

[Gjs]

Hello all.
I have had a rough time trying to figure out an off sweet taste I keep getting.
I have started using a chubby fermenter and purging a keg with the co2 produced from fermentation as well as putting .3g of potassium metabisulfite in the keg being purged.
The left over beer in the chubby taste bright Clean and just what I want even after another week but i just poured the first pint off the keg after a week of carbing and it is sweet and muted in flavour.
I have had this in pales and Ipa's.

Oxidation is my guess but I am putting a fair bit of effort into mitigating this.
The next line of thought is a persistent house infection in the kegs or lines.
I should clarify I used brand new transfer lines on this beer.
I soak my kegs in sodium percarbonate after it kicks and then rinse dry and store, when I need it I put a few litres of boiling water through it and then sanitise.

Any ideas

Are you using the same base malts? I recently bought a few FWK's because of lack of time each was a different style BUT they all have a sickly sweetness to them. I àm guessing the base is same just tweek hops. Definitely going back to my own can only handle a couple of glasses of the FWK before the pallet says no more.

 

[Skillz]

I was thinking it was recipe based and have been dropping the crystal additions.
But because I made extra and was drinking from the fermenter and it tasted great I now know it's keg side.
Infection or oxygen.
Im going to go on the theory that using the co2 from fermentation to purge the keg of oxygen is not working and my next step will be to go back to doing a full keg of water pushed out by fermentation.

 

[Gjs]

I was thinking it was recipe based and have been dropping the crystal additions.
But because I made extra and was drinking from the fermenter and it tasted great I now know it's keg side.
Infection or oxygen.
Im going to go on the theory that using the co2 from fermentation to purge the keg of oxygen is not working and my next step will be to go back to doing a full keg of water pushed out by fermentation.

I also had a sneak taste from fermenter when kegging and it tasted really good I was thinking it should turn out a good drop but sneaking a taste after a few days in keg and there it was that sweet taste and it isn't going away after a couple of weeks all three different styles had same sweetness now the real problem is that those three kegs are going to take a long time to drink due sickly sweetness. Plus I have just kegged another one of my own and it is easy drinking even with still needing a couple of weeks in keg.

 

[MHB]

Diacetyl sounds like a chance.

There are several bacteria that produce Diacetyl, some of them are very good at imbedding in beer lines and they are dam hard to kill as they actually get into the plastic under the surface where they are well protected from sanitisers.
I would take a hard look at your transfer lines, either replaces them or sanitise with a Chlorinated or Iodine based steriliser, these appear to work best on imbedded infections.
Mark

 

[Gjs]

Diacetyl sounds like a chance.

There are several bacteria that produce Diacetyl, some of them are very good at imbedding in beer lines and they are dam hard to kill as they actually get into the plastic under the surface where they are well protected from sanitisers.
I would take a hard look at your transfer lines, either replaces them or sanitise with a Chlorinated or Iodine based steriliser, these appear to work best on imbedded infections.
Mark

My experience and I have had diacetyl taste only once and it is a distinct taste, it's hard to describe but it did go away over time that was my fault. But my sweetness taste is definitely in the three different style FWK'S base recipes.

 

[MHB]

Don’t be too quick to write of Diacetyl, or more properly VDK's (there are a bunch) that can be made by a whole family of bacteria. Some even make flavours like strawberries.
You have looked at a lot of other options, thoroughly cleaning and sanitising a couple of lines isn’t too hard...
Mark

 

[Skillz]

Still fighting this sweet thing.
Tried everything and more.
It could be my grains so will try another supplier and see how that goes.
Did my first true lager was really good but now a month on I'm getting the sweet thing also.
Base malts are Joe white pils and ale.

 

[MHB]

Might give you some ideas
Mark

 

[raybies]

Let me get this straight:

1. from fermenter = tastes like you expect.
2. after a week in keg = tastes too sweet.
3. what happens on the 3rd or 4th week?

Usually an infection will change the brew every day and after a week you end up with something tasting very weird, like mixing wine and beer.
Without knowing the "whole" process it sounds like the CO2 is stripping away the bitterness of the hops. My double citra IPA comes out very bitter from the fermenter and then over 4-6w it turns to a subtle marmalade bitter for a blow my mind good double IPA.

 

[Skillz]

Gets sweeter every day, the only style I don't notice it in is hazy ipa but the hops take over everything else, last few hazy beers have lasted 2 months no problems so my oxygen mitigation methods are working. My larger is now a month old and very sweet malty instead of the nice dry and bitter beer it was, pale ale shies it up even worse.

 

[rude]

I recon Mark is on the money
Sounds like VDK what yeast was in the lager , pitching rate and temp

 

[Skillz]

34/70 2xpacks 1.054og 12c
Did another batch on the whole yeast cake that is the same.