Low Attenuation with Munich Classic Wheat Beer Yeast

I use Lallemand Munich Classic Wheat Beer Yeast for Hefeweizen. Generally pretty happy with it, but it seems to consistently have low attenuation. I think it detracts a little from what the beer should be. Lallemand shows attenuation of 76% - 83% - I get around 75%. I’m using Wheat LME, so not loaded with unfermentables. About 67F fermentation temperature. Dry pitched, as recommended by Lallemand. One packet in 5 gallons of around 1.050 wort. That’s in their range, but near the low end. I hesitate to increase the pitching rate, but maybe I should try that. All the other yeast that I use, including Lallemand Nottingham, come in pretty much as the manufacturer predicts. Does anyone else get similar results?

I’ve only ever used it once - in a 3gal, 1.051 Dunkelweizen.  73%.  And I didn’t care for it at all, though I’m willing to accept full blame.

Do you know what’s in the LME? What brand was it?

I’ve used Williams and Briess. Williams describes theirs as 60% German wheat and 40% German Moravian 2-row barley. Briess describes theirs as 65% malted wheat and 35% malted barley.

I haven’t used this yeast in years. However, a 1% difference in yeast mfr prediction is pretty close. Because you’re at the mercy of the LME producer (you have no idea how they mashed) extract brewers often run into attenuation issues due to this mfr process.

While looking through the Fermentis website today, I ran across a new Fermentis yeast - W-68. They call it “A historical yeast for German-style wheat beers”. I plan to try it for my next hefeweizen.

I saw that a couple days ago.  I would like to try this new yeast.  I imagine it will be very similar to the Munich Classic.

I just used Munich Classic a few months ago.  I got 79% attenuation, went from 1.045 to 1.009 in 7 days.  Mine was all-grain, mashed at 152 F for 50 minutes, fermented at 65 F for that week, before bringing up to 75 F for another 3 days (just in case), but it didn’t drop another point after the first week.  Overall, I’m not as happy with this beer as I’ve been with liquid yeasts but it might be due to the cool fermentation temperature, next time I will try fermenting in the low 70s to see what it does.  I got mild clove and hardly any banana at 65 F.  YMMV

Your attenuation is more like I would expect. My attenuation of 75% (with a couple percent variation either way from batch to batch) just doesn’t seem right considering the grain bill in the extract. My latest batch was at 73%, and it really affected the flavor and mouthfeel. As noted earlier, attenuation is on target with all other yeasts/extract types. I think my results could be due to either the mash conditions (as per BrewBama) or the yeast. Of course it could be something that I’m doing different when fermenting the hefeweizens, but everything is the same as with other brews as far as I know. Trying the W-68 yeast will be a worthwhile experiment.

Shoot, that reminds me, I forgot to address your experience!  My feedback on that:

You used extract.  We really don’t have a great handle on exactly how they mash the wort to make the extract.  With all-grain, there is better control over this.  With extract… you get what you get.  So I do feel that is part of your issue.  Perhaps next time try a different type of extract, or from a different manufacturer.  In general, I believe DME is more fermentable than LME, not sure why but I’ve experienced it.  And some manufacturers’ more fermentable than others.  Play around with different ingredients (not just the yeast), see what happens.

the one time i used it i got 75% attenuation using extract

I’d stick with the pitch rate you’re already using and add about 5% dextrose.

Yep. I add that whenever I use LME.

Some useful suggestions - thanks. I’ve tried two different extract brands with the same results. Plan to try the Fermentis W-68. If that doesn’t help, I’ll try adding some sugar - that should be pretty much a sure thing.

In my experience, wort makes more difference in fermentability than yeast does

I guess I’ve found major influence from both the wort and the yeast. I feel that Lallemand knows their yeast, and I should be able to rely on their attenuation numbers. On the other hand, why would the LME manufacturers intentionally run their mash to create wheat extract with lower fermentability? I’m starting to think it is just variability of LME, and it’s coincidence that the Hefeweizen has had lower attenuation. Even though my attenuation is typically higher with other styles, I do get more variation when using LME than I did when I brewed all-grain. As dmtaylor pointed out, LME can be less fermentable than DME. I suspect that is what happens with age/staling. I haven’t used DME very much, but that might be worth a try. It should eliminate any staling issues.

They don’t intentionally make it less fermentable. It’s a byproduct of the process. FWIW, using the same yeast, i’ve gotten from 60-90% attenuation depending on the wort.

I just checked the dates on six Briess extract containers that I ordered on Nov 2. Date stamps: Two 2/23, one 1/23, two 7/23, and one 10/22. I’ll probably start using these in a week or two, and finish in a couple of months. I’m only guessing that age might lead to lower attenuation, but if it does, the dates on these could explain a lot.

I ck’ed the date on these: Oct ‘09

Assuming they were stored all stored well, age is a consideration.  OTOH, if the 7/23 containers were stored poorly, the date won’t matter.

With my limited experience (4 batches) with LME, I’ve found that Colby’s idea of checking the color of an OG 50-ish sample to be effective in measuring freshness.  I can post the details if there’s interest.

I’m hard pressed to be able to come up with a reason age would make a difference in attenuation.