Wyeast 3787 & medicinal off flavour

[jonw]

I have a patersbier fermenting at the moment. 2 days in it was tasting great. 4 days in and it has a pretty nasty medicinal off flavour.

Last time I made this recipe (July '12) I had the same problem. I ended up leaving the keg under the house for a week and filtering it, and it ended up OK after a few more weeks. At the time I thought that it was a batch-specific thing, but given that I seem to be getting the same problem with the same yeast/recipe 9 months later, with several successful brews in between, I think there's something to do with my recipe/process rather than it being an infection.

I've done some googling, and it seems there may be a link to chlorinated/chloraminated (if that's a real word) brewing water and these phenolics produced by some yeast, 3787 included. Anybody here have any experience with this problem and solved it? I think my local water (Sydney north) has chloramines.

The recipe is 100% pilsner mashed at 63deg, Mittelfruh @ 60mins to 18IBU, some Saaz @ 10mins to 2IBU. I used a little (5g each) Gypsum and CaCl both in the mash and the kettle. Fermented with 3787 @ 20deg - 4L starter in a 40L batch, 2mins pure O2, and the krausen's nearly climbing out of the fermenter.

Any advice on how I should treat this batch? Should I leave it primary for an extended 'clean up', for example?

Cheers,

Jon

 

[manticle]

If your water is chloraminated, that can indeed lead to a nasty dettol/band-aid type flavour in the brew. My experience of this flavour is that it may fade with a bit of time but never completely and is quite unpleasant, even in small amounts.

Not specific to 3787 although maybe some yeast strains are more prone than others to reaction.

You may need to look at some kind of water filter like carbon filter or reverse osmosis. Long enough pre-boiling may help but you need to boil for much longer than trying to remove chlorine. Otherwise campden/metabisulphite additions can help.

 

[black_labb]

That flavour can come pretty easily from stressed yeasts (belgian yeasts are prone to forming the flavour if stressed). What was the OG, around 1040-1050? I'm guessing for a patersbier?

Sounds like pretty reasonable yeast management though. Is it possible you shocked the yeast with a fair temperature difference?

 

[jonw]

The OG was 1.048. Pitching temp was about 24deg, and I think the starter was at about that temp. Then cooled to 20deg. My ferment fridge is fairly inefficient unfortunately, so it shouldn't have cooled quickly. There may have been a fair amount of yeast growth above 20deg. Is that likely to contribute?

When I took the gravity after 2 days it was at about 1.020. Today (after 4 days) it's at about 1.015.

 

[Jace89]

Its possible these flavors your experiencing will clean themselves up, especially if the beer itself is still fermenting.

4 days into a fermentation is quite early.

Just wait and see what happens, if the off flavors are still in the finished beer then begin to worry, Hope it turns out well.