A Mystery

[RobZamites]

Dang it. I brewed what I thought was a fine old ale, tasting during kegging time reveled nothing awry. I followed the same kegging procedure (including the same concentration of caustic cleaner) with my Mini King as I have for the past 100+ bbls of beer.
Issue: I just tasted samples from several kegs, and the product has a quite pronounced dishwashing liquid aroma. Various people can taste it to some degree, but everyone can for sure smell it.
Any ideas? Does and old ale go through a stage where it might have a soapy tasting/aroma characteristic?
I'm pretty close to deciding to dump the lot, but wanted to see if anyone had some input on whether I should stand on it for awhile to see if it improves, or at what point in my process I might be on the lookout for something that might have caused this.

thanks,

Rob

[scott isham]

I think there are three things that may give off a soapy flavor; One, beer that stays on the yeast to long in the fermenter can give off a soapy flavor. Two, improper rinsing of you equipment (kegs, fermenters) can leave an alkaline contamination. Three, I think I once read that old hops may also give a beer a soapy flavor, although I'm not sure about that one. I don't know if any thing can be done about it. I doubt it will ever get better or go away. I would focus on your keg washing procedures first and make sure the kegs are being well rinsed. On the other hand, being an Old Ale, they tend to set around a while, sometimes on the yeast to long.

Scott

[Enkidu]

I don't believe that residual caustic will provide a dishwashing liquid aroma. Never the less, you should check the the pH of your product. I would be more inclined to believe that you are smelling saturated fatty acids. Did you use a new yeast strain? On the bright side, some of the fatty acids will eventually oxidize and beak down to form 2-trans-nonenal. You just have to decide if you like carboard better than soap.

[Tbrew]

Don't count on measuring the pH of the beer to check for caustic contamination. The residual caustic will react with the CO2 purge of the keg to form carbonic acid thus more than offsetting the base. To check for caustic contamination you need to do a sodium analysis on the beer. If you at all question caustic contaimination of the product you must do this test (call some local water labs).

A dirty check of the keg washer can be done by running a wash cycle with the CO2 and fill cycle turned off, then titrate to see what the concentration of the residual rinse water in the keg is (your chem supplier can supply kits if you don't have one on site). The soapy character could be due to surfactants/antifoam in the caustic if a built formulation (tap your supplier’s knowledge on this one).

Your right to consider tossing this batch and you are also on the right tract to find the source before it happens again. I hope you really do have some subtle yeast problem of some sort but from your description of "everyone" perceiving the off flavour I'm guessing it can't be minor.

If in doubt, throw it out.

Hope this helps.

[zbrew2k]

Some breweries measure the sodium ion concentration of the beer to detect a caustic intrusion into the product.

Maybe you could find a local lab that does water analysis, and get them to check the sodium of the beer from a suspect keg.

You need to know the sodium content of your brewing liquor also to compare the content.

The best test is what you did though, and taste the beer. If it doesnt meet your standards, that should say it all. Ask a few more opinions if in doubt.

Good luck,
B

[Greenbrewmonkey]

Hello All,

I think the above have stated the most likely causes. Once the cause is found, future prevention may present itself.

An additional opinion, well two really: 1) Make sure your sampling device / taps / lines are not contributing / adding to the problem. Unclean taps and lines can wreak havoc on an otherwise fine beer. And 2) if it is the beer, I vote fatty acids, and I vote yeast (although cheesy and goaty or sweatsocks could be hops) and as such, an aroma / flavor as you've described I have never known to dissipate (without the fun trade off mentioned above.) And it does your brewery no long term good to sell beer you know to be substandard. As painful as it may seem, it is probably far less damaging to dispose of it than to sell it. Not to sound all "whatever"; but a brewer in a small craft brewery with the usually limited controls who claims to have never had to dump a batch has either not been brewing for long, or has at one point served some not so good beer. Do your customers a favor. Be one of the cool kids, and dump the dishwater.

Aloha,
Ron
PS Look on the bright side, you get to brew it again!

[The Gooch]

If you think the problem may lie in your keg washer maybe you could clean another keg and then fill it with water, let it sit for a while and then taste the water to see if there is in fact contamination. Just a thought.

[RobZamites]

Thanks for the help, folks. It boiled down to a simple lack of pH testing the caustic solution in the washing side of the keg cleaner. I kegged off an IPA, made sure the pH of the caustic was around 10-11, and bingo! Great beer.

Thanks,

Rob