Land Grant University – Yeast 101

Last night Land Grant Brewing held their first session of what they call Land Grant University, a series of educational sessions on the key ingredients in beer.  The inaugural session was devoted to yeast, future sessions will focus on hops, malts and water.  Attendance was capped at 50 participants and there was a full house on hand to learn more about man’s favorite microbe.

The event came with a handy pocket sized booklet that contained eight pages of basic facts on yeast and its role in brewing, as well as details on each of the six yeasts that were profiled during the class. Over an hour and twenty minutes the Land Grant brewing team covered the basics of yeast including its history in brewing, the chemistry of fermentation, some of the flavors yeast imparts to beer, differences between different sub-categories of yeast (American, Belgian, English, etc.), and several other topics.  The similarities and differences between ale and lager yeasts were discussed at some length.  The Q & A session that followed the presentation was particularly spirited, lasting almost an hour.  The cost of the class was $25, and included a voucher for a free beer after (or before) the tasting session.

The information content was largely geared toward people who know their way around a beer but have little to no homebrewing experience.  That’s not to say there weren’t some interesting tidbits of information even for the seasoned homebrewers in the audience.  The most informative portion of the class for amateur brewers was the chance to taste samples of six beers all made with the same water, malts, and hops, but each with a different yeast.  Using the Land Grant pilot system they brewed 40 gallon batches of their flagship 1862 Kölsch with five different Belgian and French yeast strains.  The Kölsch is a relatively straightforward clean beer that allows the yeast flavors to shine through, which made the comparison invaluable. To finish the tasting we were served the standard 1862 ale, brewed with the Kölsch yeast for comparison.

For those of you who weren’t able to attend, here are my tasting notes on the yeasts that were profiled.  If you are thinking about brewing a Belgian ale, or maybe even a hazy NE IPA you might find the comparisons useful.  I’ve tried to keep my notes pretty simple, because everyone’s palate has different sensitivity for picking out the fine details.  Click on the hyperlinks to get the specs from White Labs (WLP = White Labs Product).  The folks at Land Grant were kind enough to share the attenuation numbers with me.  For those not in the know, % attenuation is the percentage of sugars that the yeasts convert to CO₂ and ethanol during fermentation.

Note that these beers were fermented starting at a temperature of 62 °F, and while there might have been some rise in temperature during fermentation the brewers did keep a control on the temperature so it didn’t rise too high.  It’s worth nothing that those temperatures are on the cool side for many of these yeast strains, if you ferment at higher temperatures you are likely to get more pronounced flavors and aromas.

French Ale Yeast (WLP072)

• Ideal Fermentation Temperature: 63-73°F
• Flocculation: Medium/High
• White Labs Attenuation Range: 68-75%
• Actual Attenuation: 85%

White Labs suggests this is a good strain for Biere de Garde, blond, amber, and brown ales. It was one of the least hazy of the beers of the evening, indicating a reasonably high level of flocculation.  The aroma and flavors are best described as lightly fruity, with the fruit flavors leaning toward pears and apples.  There was the slightest hint of bubblegum in the background.  Aside from the Kolsch yeast this was the cleanest fermenting yeast of the five Belgian and French strains profiled.

Bastogne Belgian Ale Yeast (WLP510) 

• Ideal Fermentation Temperature: 66-72°F
• Flocculation: Medium
• White Labs Attenuation Range: 74-80%
• Actual Attenuation: 78%

Though White Labs doesn’t call it out, this strain is derived from the yeast used to make the classic Trappist Ale Orval (it does not include the Brett that Orval adds later in the fermentation process).  White Labs advertises this yeast as being less flocculent than the French Ale yeast, and the finished beer was definitely hazier than the first sample.  The nose was the fruitiest of the evening, with banana and bubblegum aromas that are reminiscent of a hefeweizen.  The flavor has more of a phenolic profile, with a spicy, peppery finish and a subtle touch of cloves.  The finish was drier than the attenuation numbers would suggest.  This was my personal favorite of the evening.

Belgian Golden Ale Yeast (WLP570)

• Ideal Fermentation Temperature: 68-75°F
• Flocculation: Low
• White Labs Attenuation Range: 73-78%
• Actual Attenuation: 85%

This strain is derived from the yeast used to the make the classic Belgian Golden Strong ale Duvel.  This beer was also hazy to the point of being opaque.  The aroma is more restrained here, personally I don’t get much fruit on the nose.  The taste is a little difficult to describe, very Duvel-like for those of you familiar with that beer.  To me the most distinct element of the taste is a peppery spice at the finish, there is an earthy funkiness as well.  To my palate the fruity esters are less pronounced than the first two yeasts. The finish is very dry, consistent with a highly attenuated beer.  Personally Duvel is not one of my favorites among the pantheon of Belgian beers, so I’m a little lukewarm on this yeast.  However, it’s undeniably a classic of the beer world, and this was the favorite of the brewing team at Land Grant.  So much so that they chose to use this yeast for their recently launched foray into Belgian beers: Oval Beach Belgian Blond and the soon to be released Dubbel Overtime Belgian Dubbel are both brewed with this yeast.  I tried a glass of Oval Beach at the conclusion of the tasting, and it too is very much in the Duvel vein.

French Saison Ale Yeast (WLP590)

• Ideal Fermentation Temperature: 69-75°F
• Flocculation: Medium
• White Labs Attenuation Range: 73-80%
• Actual Attenuation: 89%

Many brewers favor this strain over the Belgian Saison strain (WLP565) because WLP565 has a tendency to stall during fermentation.  Land Grant has dabbled with this yeast in the past, using it in small batch runs of the Judas Priest Saison series of beers The Sentinel and Hellion.  This beer was hazy, similar to beer #2 (Bastogne Belgian Ale Yeast).  The aroma of this beer was immediately recognizable as a saison, with a healthy dose of phenolics mixed with some grainy malt character.  It drinks like a saison as well, with that characteristically phenolic, spicy profile.  Although the attenuation here is among the highest of the yeasts profiled, I didn’t perceive the dryness to be as pronounced as the previous beer (Belgian Golden Ale Yeast).

Belgian Strong Ale Yeast (WLP545)

• Ideal Fermentation Temperature: 66-72°F
• Flocculation: Medium
• White Labs Attenuation Range: 78-85%
• Actual Attenuation: 89%

White Labs recommends this yeast for Belgian dark strongs, Abbey Ales and Christmas beers.  Perhaps my palate was getting a bit fatigued by this point but this one seemed less distinctive than the previous three.  Definitely not as phenolic as the French Saison strain, moderate to low concentrations of fruity esters somewhat like the Belgian Golden Ale (Duvel) strain, but lacking the same interesting earthy/funky profile.

Kölsch Yeast (WLP029)

• Ideal Fermentation Temperature: 65-69°F
• Flocculation: Medium
• White Labs Attenuation Range: 72-78%
• Actual Attenuation: 87%

This yeast, the one that Land Grant uses for their Kolsch, gives a very different aroma and flavor profile.  For the first time in the evening I was able to smell the Cascade hops on the nose, although that is likely due to the dry hopping that the 1862 Ale receives, but beers 1-5 did not.  Unlike the other beers, bready malt flavors play the leading role in the taste, supported by a subtle fruity contribution from the yeast.  Maybe it’s my imagination but I can get the slightest touch of sulfur at the finish.  The Kolsch yeast is known as one of the cleanest fermenters in the ale yeast family and that is born out by the way this sample drinks.  If I’m not mistaken Land Grant also used this yeast to make their Marzen, Lawnraker, which held its own in my blind taste test of Oktoberfest/Marzen beers last fall. So homebrewers looking to make beer with lager like character, fermented at ale temperatures might want to consider this yeast.

At the end of the tasting there was an informal poll of the audience to identify the most popular yeast.  Perhaps not surprisingly there was no clear winner, with each of the five Belgian and French yeasts getting a pretty similar number of votes.

Conclusions

In closing I should point out that Land Grant does have all six beers on tap, so you don’t have to take my word for it.  Get down to the taproom and take your own tasting notes.  It’s a hell of a lot easier than doing the same experiment on a homebrew scale.  If you are inclined to do that I recommend you head down to Franklinton soon, the small batches are not likely to last much longer than through the weekend.

Keep an eye out for future sessions of Land Grant University, offered on a quarterly basis.  If this one is any indication they will sell out pretty quickly.