Posts Tagged ‘beer chemistry’

How do I do that? Modifying Water Profiles

Friday, August 7th, 2009

It should seem pretty obvious that water profiles have a significant effect on a brewer’s final product. The mineral content of the water used to brew beer can affect mouthfeel, flavor, aroma, and appearance. Every sensation we experience when drinking a beer can be changed and even improved with an altered water profile. It’s between 85% and 97% of your beer! Oddly — as you may have noted in one of my questions with Les — a lot of brewers don’t even think about it until they’ve reached a certain level of experience. Why not?

The answer? Because a lot of effort, science, and money goes into controlling this aspect of your final product. Keep reading and you’ll see what I mean.

First and foremost, it’s important to understand what the chemical salts, ions, and minerals dissolved in water do to your beer, it’s also important to note what NOT having them present does to your beer. Using pure water is not only almost unheard of in beermaking — due to the cost of distilled water — it actually doesn’t really make good beer. More on that later. Water as we know it out of the tap, out of the spring, out of the well, out of anywhere but a still is not just water — it’s a solution that contains minerals, salts, and metals that all have an effect on what we use it for, and how it tastes. (more…)

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Posted in Brewing, How do I do that?, Science | 3 Comments »

Skunked Beer

Tuesday, April 14th, 2009

You’ve all had ‘em before — a beer that smells like you ran over it on the road. You’ve also probably heard some of the various explanations as to the cause of this phenomenon — green bottles, light, heat, age of the beer, etc. But let’s get down to the real science behind why that Heineken bottle you opened smells like a woodland weasel did some exploring in there.

First and foremost, it has nothing to do with heat. While the flavor of your beer can be affected by temperature extremes, for the most part once it’s bottled as long as it isn’t being left in a hot car for days at a time it probably won’t be particularly hurt by temperature change.

So the answer we’re looking for is light. This means that — yes — the color of the bottle has an effect on the flavor of the beer. Green or clear bottles are more likely to be skunked than brown — brewers would refer to such a beeer as being “light-struck.”

Here’s the thing, that skunk smell you’re tasting is actually the same set of chemical compounds emanating from the skunk’s scent glands. Certain chemical compounds in beer that were derived from the hops —  isohumulone  to be exact — are reactive to certain wavelengths of light — those about 5,000 angstroms. What happens is that these molecules are broken apart by the light, and then rebond with sulfur compounds in the beer, creating the familar mercaptan thiol that we recognize as the smell of skunk. It smells kind of like really intense garlic in high concentration, but in beer the amount of molecules you’re perceiving is usually extremely low. (more…)

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Posted in Geek-Out | 3 Comments »