Wednesday, July 23, 2014

West Yorkshire Yeast Review

Admittedly, while I didn't get around to brewing a whole series of bitters and milds with the West Yorkshire yeast as I had hoped to do, I did end up brewing two beers with it and those brews have been on tap for some time now. See, back in late May, I decided to give a few other British yeasts a go - thinking I might find another favorite - and settled on the West Yorkshire strain as the first of the bunch. I think what made me want to give this yeast another go, after a previous string of so-so beers, was that this yeast is a nice top cropper and it has a rather vocal fan base of home brewers who seem to love this yeast for every British beer style.

The first bitter I brewed was of the ordinary kind; MO/GP pale malt, torrified wheat, crystal malt, and straight EKG for hopping. I did a bit of tweaking with the yeast pitch - went through the trouble of doing a yeast count with a microscope and hemocytometer - and even tried to slightly under pitch to coax out some complex esters. The fermentation took right off and exhibited all the signs of happy fermentation. When the yeast produced a beautiful second krausen, I top cropped the yeast and pitched it into another brew, within a few days.* The only thing I did differently was that when it came time to keg the beer, instead of not dry hopping it as I had planned, I decided to rack it into a secondary and I ended up dry hopping it with 1/2 ounce of US Brewers Gold.

The resulting beer is nice and pleasant enough... but in the same vein as a company get-togethers and eating Sunday dinner with the in-laws. It's ok, but not necessarily something you'd want to do each week. When I first tasted the beer going into the keg, it tasted lovely, but from then to now, it's lost something. Hiding beneath the lemony-herbal hop character is a beer that is fruity, clean, and exhibits a crisp, bready malt character that reminds me of quality German lagers. That said, one could find fault in it for tasting a bit thin and watery and it certainly isn't the most exciting or flavorful beer I have ever brewed. Again, it's not bad... but not great. However, what really kills this beer for me, is unlike those beers brewed with my standby Bedford yeast, this beer completely lacks the richness and yeast-derived complexity that I've come to expect with many British yeasts. Also, annoyingly, the yeast did not flocculate as well as I had hoped - it performed about the same as before - and as a result, the beer has somewhat of a haze issue.

Ok, so not the best results with the ordinary bitter. So what about this second one? Well, that beer was basically a standard ESB recipe, brewed with Glen Eagles Maris Otter with a blend of medium and dark crystal malts. Hopping was all Challenger, probably my favorite UK hop, and the yeast was pitched into well oxygenated wort. Fermentation took right off and after nearly three weeks in the fermenter and time spent crash cooling, the beer was kegged without any dry hopping. It tasted fine going into the keg, a tad yeasty, and it has been there for three weeks now.

And again, the beer is just ok. As there is little late hopping to get in the way of the yeast and malt character, the yeast flavor comes through very well... almost too well. The beer has more fruity esters than I had expected or hoped for... exhibiting a slightly peachy-banana flavor. That said, the malt comes across as bready and crisp. But where that bready malt character should transition into a rich and full flavored beer, the whole thing falls off into a dry and 'flat' fruity flavor. Honestly, the beer reminds me of a more caramelly tasting Coopers Sparking Ale. Maybe this beer is still too young - I'll give it another week or two - but I don't have high hopes for it. And again, this beer has the same hazy apperance that the other beer has. Two disappointing beers in a row. Bummer.

If there is anything we can take away from this yeast experiment, it is that while I haven't had much luck with this yeast, it doesn't mean that you will. Part of the problem may be that I have formed too narrow of an idea for what I want my British ales to taste like. Not all yeasts produce the same tasting beer and maybe if I didn't have such high expectations, I might be able to enjoy these beers for what they are.

That said, I probably won't be revisiting this yeast anytime soon... although I would love to hear from people whom have used this yeast with good results.


*Aside, I realize that I have been blabbering on about top cropping and storing yeast for years now, all the while never mentioning how I do it or why doing it a certain way might be beneficial. We'll here you go; I originally wrote this for a home brew club event I did a few months ago.

A word or two on top cropping. Unlike what is often assumed, top cropping is actually a pretty delicate operation and there is a whole bunch of very interesting yeasty science behind the procedure. In short, if you want the healthiest yeast from your fermentation, don't just skim whatever yeast is on top of your fermenter at any given time. To sum things up, the best way that we home brewers can top crop, is to pitch an adequate amount of yeast in the first place and then wait until the first krausen shows up, usually around 24-36 hours. This first krausen or "first dirt" mostly consists of proteins, hop oils, and other stuff that we don't want in our beer or cropped yeast. The first dirt is skimmed off and discarded. After that, we wait until the second krausen (or high krausen) is formed, which should be around day 2 to 4 or when the yeast has fermented just over 50% of its fermentables. This yeast should be both airy and creamy and free from all hop particles. This is the yeast we want. Using a sanitized utensil, skim this yeast off into a sanitized container and if you are planning to store the yeast for more than a few days, be sure to submerge the yeast with a thin layer of beer. Do not mix water with yeast!

Interestingly enough, adding water to stored yeast (usually via "yeast washing" - separating yeast from trub, usually with de-aerated water) is among the worst things we can do when saving our yeast for extended periods of time. See, when beer undergoes fermentation, the yeast do their part to form a rather inhospitable environment for any other yeasts and/or bacteria that may be in the solution. In the simplest of terms, they do this by consuming available sugars, eliminating free oxygen, lowering the PH of the solution, and lastly by producing alcohol. All of these things make it rather difficult for many beer spoiling organisms to survive. Now, when we take the yeast out of this environment - via top or bottom cropping - and replace the beer with water, we are in effect completely undoing everything the yeast did to help preserve itself. Adding water increases PH, decreases alcohol, adds oxygen (whether we realize it or not), and provides a friendlier environment for bacteria to replicate. In short, if you are going to store yeast in a solution (top cropped or washed), you are better off leaving your yeast under a layer of fermented beer and dumping that liquid out before re-pitching.