I’ve had issues with my last several lagers and I am pretty perplexed. I don’t do a lot of lagers but have done probably around 20 over my 11 years of brewing. My past five or so batches have had varying degrees of off flavors. I’m usually good at diagnosing problems but anything I’ve changed hasn’t seemed to remedy the problem. I believed the off flavor was a fusel and a friend with a great palate said the same without me telling him my opinion first. I’ll lay out the different things I’ve done and see if anyone else can pinpoint where it could’ve gone wrong:
- Most times I split batches and do two different yeasts. Sometimes I’ll do a kolsch in one and a lager in another. The kolsch doesn’t have the off flavor but the lager will.
- Different styles and recipes: maibock, Baltic porter, helles, o-fest, Schwarz.
- Three different yeasts, Bavarian, Munich and Augustiner. Some repitches off of previous batches, some new pitches grown to full sized starters.
- Hit with pure oxygen at pitching.
- Pitching at fermentation temperature.
- In one case, beer was done in four days so did diacetyl rise and got the flavor. Next time, I let it sit for two weeks before checking gravity and letting it rise. Same fusel flavor.
- Fermented in both glass and plastic at a consistent temperature, though varied over different batches from 46-54F.
8 One of the batches I did a protein rest, most of the others were single infusion with no mash out. Same fusel flavor.
- No problems with ales made in the same system, same filtered campdenized water.
- Almost all Weyerman malts. Same flavor over the course of two different bags of pils.
Like I said, I feel like I’ve addressed everything that could cause it and have no idea what could be done differently. The only two suggestions I’ve had (and I plan on trying them) are to pitch at knock out temp and then drop down to fermentation temp and after two days at temperature, let it free rise to about mid-50’s. Any other suggestions? Thanks guys!