Friday, 8 May 2015

Saison Yeast Blends

As anticipated, after a vigorous start to fermentation my saison brewed with the Wyeast version of the Dupoint strain stalled at around 1.030, and has been slowly attenuating further ever since.  I'm in no rush, so I'm happy to leave it for another few weeks until the yeast drop out of suspension.  If its not dry enough at that point, I'll add some brettanomyces and let it age for another few months, but based on other people's experience with the strain I don't think that will be necessary.

All of this made me even keener to try out my own yeast blends, using the Dupont strain along with other organisms.  It seems that people generally agree that the 'leaven' at the Dupont brewery consists of a number of different strains (including wild yeast), and I've read plenty of interviews with U.S. brewers who like to use the Dupont strain for its flavour profile, but pitched along with another strain to ensure a fast and reliable fermentation.

So I knew I was going to make a blend of at least two yeast strains.  The question now was what I should pitch along with the Wyeast Dupont strain.  Wyeast French Saison strain (3711) seems to be the most common choice here, since it ferments quickly and produces a very dry beer, albeit with some residual mouthfeel due to its high glycerol production.  I've pretty much sworn off using this strain because I don't really like its flavour profile (which means I don't like a lot of American saisons!).  Perhaps it would express itself differently as a small proportion of a blend, but since I already had a pitch of Wyeast 3726 on the go, I decided to use that instead.  This is reportedly a version of the Blaugies strain, which in turn is supposed to originate from the Dupont brewery.  All the more reason to use it in the blend then, especially since it reliably attenuates my saisons to within a few points of 1.000, and produces a flavour profile I quite enjoy.

I settled fairly arbitrarily on a blend of 70% Dupont to 30% Blaugies.  My thought was that this would be a large enough proportion of Dupont that it would dominate the flavour profile, but with enough Blaugies that it also contributed some complexity along with taking over in the second half of the fermentation and ensuring the beer dried out in a reasonably short time frame.

Both yeasts came from the cakes of recent saisons.  I got out my copy of Yeast, along with a microscope that I purchased second-hand thanks to a fellow brewer who runs one of the labs on campus, and had a go at serial dilution and yeast counting to work out how many cells I had per ml in each cake.  I'm not completely confident in my procedure here, so I won't write it up (I followed the instructions in the book, diluting the yeast by a factor of 1000, counting the number of cells I could see on a hemocytometer, then working from here to a number of cells per ml).  Based on these numbers I measured out three pitches of roughly 100 billion cells, a slight overpitch given that each was going to be 12 litres of 1.040 wort, but I hadn't taken the viability of the cakes into account in my original calculations, and I figured it would be better to overpitch than underpitch.  Interestingly enough the final blends contained smaller slurries than I usually pitch, which means I've been overpitching by a significant factor for a while now.  I got a quick start to fermentation, which suggests I didn't mess up the count too much, so as I become comfortable with this process I'm going to use it more frequently to determine the volume of yeast I re-pitch.  (Incidentally, you don't need a microscope to come up with your own blends: check out Dave Janssen's procedure here.)

So now I had three pitches consisting of 70% Dupont and 30% Blaugies.  But what about the 'wild yeast' the Yvan de Baets says Dupont keeps in their leaven to ensure complexity?  The Wyeast 3726 has been through several generations in my saison equipment (i.e. scratched up buckets that have had plenty of brettanomyces in them), so there's a good chance its already not a pure culture.  I decided to keep one pitch as it was, with just these two strains.  For the second, I added about 20ml from a fermenting starter of the recently released Wyeast Brettanomyces Clausenii; and for the third, I added half a vial of The Yeast Bay's Amalgamation blend.

Three pitches, three saisons.  If I were a proper blogger I'd probably have pitched each blend into an identical beer to compare the results, but its not easy to make enough beer to make that worthwhile on my set up, and I wanted some variety anyway.  Instead I compromised, brewing three beers with the same grist but using different hops in each one.  The grist was mainly pilsner with a little bit of golden promise and malted wheat, aiming for an O.G. in the low 1.040s.  I picked the hops fairly arbitrarily based on how I imagined the final beers tasting, in each case going for a 2:1 blend for everything except the bittering addition (60, 20, 5, 0 minutes).  Here's what I ended up with:

Dupont/Blaugies saison: blend of Crystal and Sterling.

Dupont/Blaugies/Brett. C. Saison: blend of East Kent Goldings and First Gold.

Dupont/Blaugies/Amalgamation Saison: blend of Huell Melon and Hallertau Blanc.

I brewed all three batches last weekend, keeping each beer below 70 for the first 12 hours of fermentation and then allowing them to rise from there.  I haven't taken any measurements, but fermentation started quickly and each beer has been more active than the saison pitched with Dupont alone.  I'll rack them to secondaries over the next few weeks (all my carboys are tied up at the moment), and at that point I'll take measurements and make decisions about bottling timeframes.  I'm hoping to get them packaged in the next month or so, so that they can condition while J and I take a trip back to the U.K.  So, expect tasting notes in a few months!

I'm hoping to repitch each blend at least once as well: it will depend on (a) how each beer tastes when I rack it, and (b) how much brewing I get done before we leave.  Right now I'm thinking I'll use the Amalgamation blend in a version of my Buckwheat Saison (and cut it with the final gallon from my first pull of the Roeselare Solera); split the Brett. C. cake between a bitter spelt saison and a saison fermented with LAB along with the blend; and use the Dupont/Blaugies cake in a petite saison made with wheat and/or spelt (a 'grisette', if you insist).

No comments:

Post a Comment