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I have an ongoing infection in my beer.


Has anyone ever encountered a fermentation like the pictures attached? Over active fermentation, yeast coming out through airlock, viscous bubbles resulting in a bitter, long lasting, aftertaste?


This has happened in 3 of my last 4 brews.


I have made about 55 AG beers and not encountered it before. Sanitation with Star San, this is the third different fermentor I have tried.


All three brews have been low colour predominantly Gladfields Pils/Pale Ale to make a Cream Ale, 75 minute boil, OG 1.046-1.048. Measured OG pH in last beer and it was high at 6.0. Pitched approx. 20g US05 (two new packs), rehydrated at 23 degrees into 24L.


Fermenting at 17 degrees to get a clean flavour (haa!), fermentation begins fine then on day three the krausen begins to rise and by day six I have what you see in the picture.  


Not looking forward to another 6 hour brew day to then unceremoniously (and angrily) dump it.


Please help as I’m afraid that the rest of my life may be filled with cheap commercial swill…  

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Yep too much yeast. 

It not an infection.. that is just yeast. You could scoop some of that into a sterile jar for your next brew.

I think its starting slow as 17C is the lower end for that yeast... but with two packets on a sub 1.50 brew, probably too much.

Yes you need a good healthy dose, but a rehydrated single packet is all Safeale would recommend.

Isn't worst case scenario for over pitching an overly dry beer and low ester production? Not production of off flavors that would leave the beer undrinkable.

2 packs into 24L is not even close to the level of over pitch you would get form re pitching a new beer directly on the whole yeast cake of an old one. And the reports I've read from folks who have done that are like: it took off like a rocket blew out the airlock and fermented out in 48hours, the final product was a little to dry but otherwise good.

6 days to get to that state also points me towards infection as a sub 1.50 brew with correct pitch rate of us-05 would be slowing down if not finished by then with high krausen at about day 3.

That's my '6 day' assumption too.

It's the sour taste that makes me think it's an infection.

Safale 05 factsheet indicates 50g-80g per 100L so while tapping the upper limits, I am within their guidelines.

Have you always pitched this rate before?

Have pitched this amount in my last 7 or 8 brews.

No problem with Stout, Pale's but the three very light beers that have displayed this problem contain only base malts - Pilsner, Pale Ale and Munich. 

Pitch rate is fine if online calculator are to be believed and Fermentis's Safale 05 fact sheet suggests 50-80g per 100L. I am at the upper end of this limit but it has been successful in the past.

Pilsner Malt - How long are you boiling for?

75mins for two of them, 90 mins for the first one that went off.

I don't see anything wrong with your krausen etc. its generally a good healthy fermentation.

I would question your fermentation schedule. you say 17deg C - are you leaving it at this temp forthe full ferment? or are you increasing temperature?

Given you have helathy yeast, its not an infection.

but if your not ramping your temp (Especially for US-05) then that bitter aftertaste, would be the Diacetyl taking hold of you hops, and the perception would become higher (I've hadthis issue) especially at 17 degrees, your more in danger of gettingthis, if your not doing a rest temp.

the other issue also could be you over bittered your beer, 

it could also be hop astringency, but that would depend on he style as well.

Tend to ramp up to 21 degrees on about day 5 to blow out any remaining sugars and let the yeast clean up. Hold that for 3-4 days before cold crashing and kegging.

This beer had 30g Motueka @ 60mins for about 23 IBU's.

I've found that beers with US-05 are more serseptable to diacteyl, using the lower ferm temps (similar to a lager) so my advice would've been to increase the temps a couple of days earlier at least.

However, like i said it may not be that. but ive noticed increased bitterness when diacetyl is present in the beer.

you wont know what its really like until you bottle/keg it.

google forced diacetyl test, and try that out, that might give you an idea on whether thats your problem.

you mentioned a sour note? can you describe it?

I think the off flavour is phenolics. Found multiple instances in blogs of people using US05 with great results then, bang, bang, bang it all goes haywire.



Moved to a different yeast, fermenting at the moment, will report back with results.


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