My most recent helles (OG 1.050) finished at 1.005. This is a real head scratcher for me. Maybe some of you guys have a few ideas as to why this happened. It’s way too dry with too much alcohol.
I’ve brewed probably 7-8 helles lagers and all of them have had a malt bill that is roughly 90% German pils and 10% German light Munich (6L). I’ve done a number of single infusion mashes (at 150F) and a couple of hockhurz double decoctions. Either way, my target gravity is always 1.050 and my finishing gravity is always 1.010 – always. The only thing I did differently this time was add a small portion of acid malt to adjust the mash pH (which was 5.3 on the nose) and use WLP833 Bock Lager yeast instead of my usual Wyeast 2206. The yeast difference doesn’t make sense to me, since 833 is supposed to be slightly less attenuative. I pitched the same amount of yeast as I normally do too (2 vials in a 2L stirplate starter). Aeration was as usual, with a mix-stir.
I’m honestly stumped. This beer was supposed to be on showcase for my Oktoberfest party on Saturday. I’ll still be serving it, but I’m going to rebrand it as “a bavarian-style light lager with a decidedly dry, crisp American lager finish.” It will be called Einwanderer, or immigrant.
Have you calibrated your thermometer and hydrometer recently?
That’s 90% AA which is high for that yeast. I wonder if you mashed lower or got a bad gravity reading somewhere along the way.
Also try checking the beer pH. The only other thing I can think of is a lacto type infection which would give it an initial dry/tart flavor. How old is the beer? Yeast contamination is another possibility.
Thermometers and hydrometer are calibrated (I think – I’ll double check next brew session). There are no off-flavors or flaws in the beer. It just tastes absurdly dry.
I like the blending idea, and I’ve always wanted to try that. But I’ll be serving this beer at my Oktoberfest party tomorrow. I’m just going to brew another helles soon, maybe with a slightly tweaked recipe. I’ve been thinking of adding 5% carapils and increasing the mash temp to 153. I know adding carapils to a helles is heresy to some, but the 2011 NHC gold for German lager went to a helles for which the grain bill included 10% carapils. Maybe there’s something to that. Or not.
Could fermentation temperatures be a factor?
If you’re using a different yeast, could it be that they attenuated better at your temp?
That said…I have noticed this in my beers, before & was never able to find the cause.
It just seems that I frequently have extremely dry fermentations.
I have been getting 1.008 FG lately, too. Everything calibrated correctly, so I am beginning to think I may be overpitching (lagers with half a slurry and ales with around a third of a slurry). Just a slight bit drier in the finish. Or maybe it just has to do with using successive generations in my case. I don’t go over 4, though…
Driving the mash pH down does increase the fermentability of the wort. That acid malt addition probably was the culprit. A couple tenths lower pH can have a substantial effect on fermentability.
The 5.3 pH measured is at the lower end of where I prefer the mash to go. I have had mashes at 5.2 and can assure you that the result was substandard for me…far too attenuated (the malt character was gone) and I could pick up a hint of sourness in the flavor profile. Aim for 5.4 in your mash in most cases and you can bump that up a tenth if reduced fermentability is desirable.
In my opinion, mash pH may be one of the final frontiers for tuning wort and beer performance. Bru’n Water is the tool to use for figuring out that tuning adjustment.
This makes a lot of sense to me, Martin. I have been aiming for 5.3 for the past several batches and have noticed that fermentability has been slightly higher. It was most noticeable with this helles, but I also noticed it in my amber, which I brew several times per year. I didn’t notice such a drastic difference in attenuation with the amber, but that’s likely because of the presence of 10% crystal malt.