Day 78

There’s some things you just have to grit your teeth and get through, knowing that it’s good for you and it will help you in the future. For instance, sex ed classes: not nearly as enjoyable as sex, sometimes off-putting or even unpleasant; but once you were finished them, you could again enjoy getting messy with an agreeable partner while saying, “Gosh, I’m glad those classes are finished.” (Well, I’m sure that was the gist of what you might have said.)

It was the same with Sensory Evaluation today. Tasting beer at 8:30 am is supposed to be an enjoyable exercise, but not when Roger Mittag spikes jugs of perfectly good beer with off-flavours. We had to smell and taste each one (and take notes) so that we would know what was wrong with our beer if we ever smelled or tasted that flavour again.

Diacetyl: smells like the butter that is used on popcorn, or at higher levels like butterscotch. You have a fermentation problem–either a bacterial infection, or fermentation ended prematurely.

Oxidation: wet cardboard or paper. Air got into your beer during bottling.

Dimethyl sulphate (DMS): most of the class said the aroma was creamed corn, but it was tomato sauce to me and several others. Regardless, DMS should evaporate off during the boil phase of brewing, so either your boil wasn’t vigorous enough, you didn’t boil for long enough, or you didn’t take the top off the kettle to allow the steam to vent.

Metallic: ’nuff said. I didn’t smell this in the aroma, but geccchh the taste of coppery rust. Gecchhh! Check your brewing set-up for places where copper or iron could be entering the beer stream.

Ethyl hexanoate: anise or black licorice or red apple skins at low concentrations. In higher concentrations, pink eraser or overwhelming licorice. Produced by all yeast, so in lower concentrations, a good thing, especially in dark beers. If it gets to the overwhelming stage, check your yeast.

Mercaptan: sulphurous. Again not so much in the nose, but it left a horrible flat chalky sharp aftertaste. Gnnnk! You’ve got a yeast problem.

Isovaleric: Most people said it smelled like rank locker room. I smelled cat urine, and decided to forgo a taste–I’m pretty sure I’ll recognize the smell again. The result of using old or degraded hops.

Isobutyric: Cheese. A taste that should be found between two slices of bread, not in your beer. Throw out those old stale hops and get a fresh supply.

Infection: Lactic or vinegary sourness. Bacteria got into your wort after the boil. Unless this was deliberate (there is a market for deliberately soured beers), pour the entire batch down the drain, check your sanitation protocols and start again.

Not a pleasant class, but necessary. Unfortunately, it’s put me completely off beer for the rest of the day… I think.

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