Something off in my Oktoberfest

I made a critical error somewhere along the lines in my lager Oktoberfest (And this is actually the fourth time I've made it, so it should've been fine..) and it has a weird chemicalish taste undertone to it. I noticed it a bit before I lagered it and it was still there when I bottled and now again 4 weeks later I tried two bottles and couldn't even drink them. It seems like all the flavor is there, but the acrid chemical taste just cuts through it all.

This is the first batch I've ever brewed that's been actually bad and I'm at a loss as to what it could be or what I did wrong, especially since besides tweaking the recipe a bit, I did everything pretty much the same as I always do. I brewed a different beer right around the same time (actually at the same time) and that one's delicious so it doesn't seem like it's something unsanitary with my equipment..

So what'd I do wrong?

When you say "chemical", is it like a solvent or more like a band-aid/plastic flavor?

BigB said:

When you say "chemical", is it like a solvent or more like a band-aid/plastic flavor?

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I'd go more with solvent. the taste brings up images of a coating of oil on a liquid. (although it doesn't look like that, seems to have bottled-carbonated fine)

Diacetyl?

Solvent flavors are caused by any number of problems. Solvent is best described as having a pungent or acrid aroma that is acetone, paint thinner, or turpentine-like. Taste-wise it is a harsh, burning sensation on the back of the tongue and throat. It is often caused by a wild yeast contamination, underpitching yeast (use mrmalty next time), under oxygenating (aerate better), or too high of fermentation temp (remember that fermentation temp is often higher than room air). I would review your process and see if any of those fit your situation, then adjust accordingly.

Diacetyl would remind you of buttered popcorn or butterscotch... and has a slickness on the tongue... but generally not "chemical-like."

BigB said:

Solvent flavors are caused by any number of problems. Solvent is best described as having a pungent or acrid aroma that is acetone, paint thinner, or turpentine-like. Taste-wise it is a harsh, burning sensation on the back of the tongue and throat. It is often caused by a wild yeast contamination, underpitching yeast (use mrmalty next time), under oxygenating (aerate better), or too high of fermentation temp (remember that fermentation temp is often higher than room air). I would review your process and see if any of those fit your situation, then adjust accordingly.

Diacetyl would remind you of buttered popcorn or butterscotch... and has a slickness on the tongue... but generally not "chemical-like."

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yeah, wasn't diacetyl. I think the beer was oxygenated and I had it in a temp controlled fridge, which granted isn't perfect, but I doubt it eclipsed 60 even.

So yeah, underpitching could be it. sucks. I wouldn't have expected it to have that harsh an effect. I don't brew at home so it makes it tough for me to manage things that have to be done, like starters, before hand. I've always been fine with this one before, bleh. Probably should lay off the lagers then.

thanks.

Ceetar said:

yeah, wasn't diacetyl. I think the beer was oxygenated and I had it in a temp controlled fridge, which granted isn't perfect, but I doubt it eclipsed 60 even.

So yeah, underpitching could be it. sucks. I wouldn't have expected it to have that harsh an effect. I don't brew at home so it makes it tough for me to manage things that have to be done, like starters, before hand. I've always been fine with this one before, bleh. Probably should lay off the lagers then.

thanks.

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Don't give up on lagers yet, just because you can't make a starter. Other options would be to buy two packets of yeast or go with a dry lager yeast like W34/70 (Which is one of my all time favorite yeasts BTW).

Lagers can be picky. If you have a temp controller for your fridge you should be fine, but massive temperature swings really pisses off the yeast. If you can keep air temp between 50-52, you should be fine, but I wouldn't want to ferment much warmer than that. Also, oxidation can sometimes come across as chemical like... you can get that from simply aerating the wort before it is cooled off... something else to watch for.

BigB said:

Don't give up on lagers yet, just because you can't make a starter. Other options would be to buy two packets of yeast or go with a dry lager yeast like W34/70 (Which is one of my all time favorite yeasts BTW).

Lagers can be picky. If you have a temp controller for your fridge you should be fine, but massive temperature swings really pisses off the yeast. If you can keep air temp between 50-52, you should be fine, but I wouldn't want to ferment much warmer than that. Also, oxidation can sometimes come across as chemical like... you can get that from simply aerating the wort before it is cooled off... something else to watch for.

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I doubt the oxidation thing. My process is usually to move the pot from the stove to the sink and cool it in there to at least 100 or so before pouring it into the fermenter. The other possibility would be that I left the carboy out overnight, figuring maybe it'd jump start the yeast a little bit and make up for the small size. I got nervous about the no starter thing, when I should've just trusted what I did for the other three lagers and shoved it in the fridge. Sloppy of me.

the Oktoberfest Yeast says 48-58, so I set the fridge at 55 for three weeks then turned it down to 48.

Probably your fermentation temp then. Simply setting the fridge at 55F isn't good enough... you could have a several degree error depending on accuracy of whatever you set (you didn't say), plus 2-3F since active fermentation runs a bit warmer than ambient. So you could have been way over. And 55F is already on the high side.

Otherwise, tell us about your water. Did you filter it? Does your supply use chloramines? Did you make any mineral additions, and if so, what's the resulting water profile?

SpeedYellow said:

Probably your fermentation temp then. Simply setting the fridge at 55F isn't good enough... you could have a several degree error depending on accuracy of whatever you set (you didn't say), plus 2-3F since active fermentation runs a bit warmer than ambient. So you could have been way over. And 55F is already on the high side.

Otherwise, tell us about your water. Did you filter it? Does your supply use chloramines? Did you make any mineral additions, and if so, what's the resulting water profile?

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The thermometer I put in there suggested it was pretty accurate. I have one of those temp controller boxes that turns the fridge on and off. I figured 55 for wyeast 2633 was within the 48-58 range and it from what I was reading it seemed like doing the initial fermentation higher was the way to go and lagering in the colder bits. I set the fridge for 58 the previous 4 times I made the Oktoberfest. It was my understanding that the Oktoberfests are fermented a wee bit warmer than other lagers.

Water gets filtered as it goes into the house, and then additionally through a sink-top device. same water I always use for everything. I don't make any additions and I have no idea about the profile. It's on Long Island, I think we get NYC water.

Oh ok, sounds like it probably wasn't a temperature problem if you're confident in the temp and you've had past success doing the same thing.

You might want to check if your city uses chloramines. From what I've read, they don't filter out. And chlorine/chloramine levels do vary even in the same city in my experience.

Btw, exactly how much yeast did you pitch? I'll guess that you've also had past success making lagers with that amount of yeast, right?

SpeedYellow said:

Oh ok, sounds like it probably wasn't a temperature problem if you're confident in the temp and you've had past success doing the same thing.

You might want to check if your city uses chloramines. From what I've read, they don't filter out. And chlorine/chloramine levels do vary even in the same city in my experience.

Btw, exactly how much yeast did you pitch? I'll guess that you've also had past success making lagers with that amount of yeast, right?

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same package of yeast in fact. I've made it five times previously, over three years. It's actually the only beer I've made multiple times. maybe I got overconfident.

If I recall (hey, this was like April) the pack got smashed on Saturday mistakenly. I did mix up a little bit of malt and water and set it aside (not a lot. maybe a cup? I just wanted to make sure the yeast was still viable and not dead), had the yeast added to it on Thursday, and then brewed with it on Saturday. Usually I just smash the package and pitch it a couple of hours later. I'm definitely thinking I panicked my way into making a mistake.

Ceetar said:

the Oktoberfest Yeast says 48-58, so I set the fridge at 55 for three weeks then turned it down to 48.

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A couple things: First, the yeast package says the range, but that is not necessarily the optimum range for flavor. A 55 air temp can result in a 60F + fermentation temp. 55 is already a wee high for a lager as it is. Secondly, if it is not an actual temp controller and only the fridge thermostat you are relying on, the temp swings could be massive... which really pisses off the yeast (see "Yeast" by Chris W. and Jamil Z.). Third, lowering it to 48 after 3 weeks for fermentation purposes does nothing. Fermentation is complete by then. Sure, you will still get some diacetyl reduction and some other cleaning, but it is more effective to ferment to within 75% of FG, do a diacetyl rest, then slowly lower to lagering temps (near freezing) for at least 4 weeks. (Again, see "Yeast"). Finally, on another post you said you started high then reduced to 55. I am a firm believer based on "Yeast" and other technical reading that is just bad practice. For one thing, the pitching rate is too small to create effective yeast growth. Next, the chance for off flavors due to high temps is most dangerous in the first 2 days of fermentation. By the time you get that gigantic mass to cool down to the appropriate temp in the fridge, the damage is already done. Now add the heating process from active fermentation... it could take days to cool down. Third, a sudden drop in temperature, again will piss off the yeast. Always pitch the appropriate amount of yeast at or slightly below fermentation temperaature and ferment cool with lagers. Lagers usually don't allow much room for error, so give your beer every chance.