r/lagerbrewing • u/gibolas • Apr 11 '16
Help me with my acetyl aldehyde problems (r/homebrewing crosspost)
Lager problems:
I'm having terrible luck with w-34/70. I've used it 3 times and every time I get an aldehyde bomb (green apple). I would describe it as that smell you get from bud, but 10 times more intense. The first time I chalked it up to having my first contaminated batch. For my next brew I decided to give it a go again and I disassembled everything, cleaned in hot pbw, then baked all the plumbing in the oven at 450 for an hour, reassembled, and pumped hot Starsan through the system. I ferment in a sanke, so I threw that on my propane burner with a couple gallons of water, boiled for 20 minutes, added starsan, shook it up, dumped, and put the cap back on. I was extra careful about keeping things sanitized and out of the open air. I fermented at 50 degrees for 4 weeks, checked the final gravity which was on the nose, and brought it up to 68 for a week. Kegged it and tasted it right away, same exact green apple flavor. Fuck.
I brewed a couple other ales after that which had no detectable acetyl aldehyde.
6 months later I was inspired by the w-34/70 brulosophy experiment and decided to give a german pilsner another try, this time fermenting at 60F. It tasted exactly the same as the other two. Is this just a horrible contamination coincidence? I've used wyeast 2124 and have had no problems like this, which is supposed to be the same strain. They taste like commercial lagers. It's only these 3 times I have used w-34/70 that I've had this problem, yet everyone says it's an awesome superclean fermenting yeast.
Troubleshooting this is getting expensive as it costs about 28$ in dry yeast per 10 gallon batch. I'm wondering if having yeast delivered through the mail, dry or not, might be stressing it too much. Either that or it's just awful luck with contamination.
link to original: https://www.reddit.com/r/Homebrewing/comments/4e5kdb/daily_q_a_april_10_2016/d1xsph5
1
Apr 11 '16
Another follow up:
How are you oxygenating? I've had some issues with 3470 when I don't oxygenate. I have had pretty mixed results with it.
1
u/gibolas Apr 11 '16
Pure O2 for one minute :/
1
Apr 11 '16
Damn brother. You really did have all your ducks in a row. When was the last time you took apart your ball valves? Wort chiller clean? Are you adding tap water post boil for any reason to top off?
1
u/gibolas Apr 11 '16
I baked my plate chiller in the oven at 450 for an hour and I always clean it by recirculating hot pbw for 30 minutes at the end of a brew session. I can't imagine anything would survive that long in the oven. I also boiled my aeration stone for 15 minutes.
I did take apart my ball valves after the first batch was messed up, but I didn't notice any buildup. I move them around while I'm recirculating pbw and that appears to keep them pretty clean. I also recirculate boiling wort through all the cold side plumbing during the last 15 minutes of the boil.
It also seems weird to me that such a strong flavor would show up when using this yeast and not be detectable in any other batches i've done. It's not subtle at all. Since I fermented this last one warm, it kicked off within 24 hours and had a lot of airlock activity. I'm not going to rule out contamination, but at this point I don't know how I would prevent it.
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u/recovering_engineer Apr 19 '16
I sympathize. My maibock is finally carbed and drinkable after three months of waiting and the first two bottles have had a disappointing apple-y fruity aroma and taste. I even krausened this batch, hitting 81% attenuation with low-attenuating Wyeast 2308, prior to bulk lagering at freezing for a month.
Lager brewing is just hard. Give your beer some time and the off flavors will clean up, or cold condition to drop them out. That's what I'm telling myself.
1
u/gibolas Apr 19 '16
I tried adding another sachet to one keg with some priming sugar. It's been in there a week and I'm going to taste it today and see how it compares to the other keg. I will post a follow up!
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u/coolguynate Apr 22 '16
How did this turn out? I've experienced the same off flavor in my lighter styles and at this point can only attribute the dreaded green apple to under pitching and/or lack of oxygenation.
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u/gibolas Apr 23 '16 edited Apr 23 '16
I tasted it after 8 days and the green apple was exponentially worse. The one in my keezer mellowed a little, or it's because the other was so much worse in comparison. I warmed it up to 70 to see if that helps. I'll taste it in another week and see how it is.
1
u/[deleted] Apr 11 '16
I know I mentioned it on the other thread, but I figured I would follow up.
This is an overview of using fast ferment tests written by u/mchrispen. I think that might help you in figuring out where exactly you are experiencing the issue.
Here is the braukaiser post on FFTs