Phenols in lagers

Several of my lagers have been a getting slight to moderate phenolic taste and odor. Some more of an odor but no taste. I was wondering if the mash tun had any factor in it as I never sterilze it since everything gets boiled that has been inside of it. It could also be bleach residue even though I think I am rinsing well. Just wondering if anyone sets about really cleaning and sterilizing their mash vessel. I use an igloo cooler. Thanks

The mash tun is not the problem. At what temp did you pitch yeast at? What temp did you ferment at. Did you do a diacytle rest? I would suspect temperature problems.

As long as you keep your mash tun clean, it won't be the culprit.

I agree with the suggestion that it could be a temperature problem, particularly if you are under-pitching. It might also be a sanitization problem with your fermenter and/or racking hoses. I would check those first before worrying about the mash tun. Hope you get it figured out!

And switch to a no-rinse sanitizer, leaving the bleach behind, just to make sure that is not the problem.


TL

Agree with all of the above. It's not your mashtun. Phenols are most likely a by-product of a fermentation that is too hot, stessed or contaminated yeast. The other cause is generally from bleach residue that combines with other compounds in the beer to create polyphenols. Watch your temps closely, make a big, active starter and get rid of that bleach.

Phenols are usually a result of the yeast strain, or if you use bleach for sanitizing, residue from the bleach. Charlie Talley from Five Star Chemicals (Star San) was interviewed on basicbrewing.com, and gave some really good advice about using bleach effectively without using such a high concentration that rinsing becomes problematic. He recommends adding 1 ounce of bleach to 5 gallons of water, then adding 1 ounce of white vinegar to the *DILUTED* 5-gal bleach solution. The vinegar allows the small amount of bleach to perform very effectively.

Make sure you treat your water for chlorine/chloramines with campden tabs or by filtering, and switch away from bleach to a no-rinse sanitiser/cleaner. I doubt it's the yeast unless you're severely under-pitching or under-aerating. Even then I would look to the water & bleach first. These can cause chlorophenolic medicinal tastes in the finished beer.

mysterio said:

Make sure you treat your water for chlorine/chloramines with campden tabs or by filtering, and switch away from bleach to a no-rinse sanitiser/cleaner. I doubt it's the yeast unless you're severely under-pitching or under-aerating. Even then I would look to the water & bleach first. These can cause chlorophenolic medicinal tastes in the finished beer.

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I've just started to treat my water for chlorine. I've been brewing up some very nice lagers and they've rated fairly decently in competitions, but I've gotten several comments on phenols. I over chill my lagers and then let them rise to and ferment at 50 F so I know that is not the source. The next most obvious source is chlorine in the water so now I've started to treat my water with camden tablets.

For anyone using bleach, a good way of making sure its gone it to first use thin bleach and not the thick stuff which is designed to hang around, rinse a few times and then do a final rinse with some water that has had some crushed campden tablets or sodium metabisuphite added to it. It'll neutralise any remaining chlorine and also its no rinse

delboy said:

For anyone using bleach, a good way of making sure its gone it to first use thin bleach and not the thick stuff which is designed to hang around, rinse a few times and then do a final rinse with some water that has had some crushed campden tablets or sodium metabisuphite added to it. It'll neutralise any remaining chlorine and also its no rinse

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Hey -- that's a great tip! Thanks.