So, now that I’ve briefly introduced bitterness, I suppose I should step back and start with a more basic subject: how you use your 5 senses and the 5 basic tastes to enjoy beer.
The 5 Senses:
We all remember from grade school that the human body’s five senses are sight, sound, touch, smell, and taste. It’s fairly obvious that smell and taste play a part in experiencing beer, but what about the others?
Our eyesight comes from light in the visible range of the spectrum striking our retinas and exciting molecules which transmit a signal for our brain to interpret. In beer, we notice the color, the clarity, the foam thickness, and the lacing in the glass. All of these things are very important in building our impression of the beer. It’s amazing how the color of the beer can bias the drinker before they’ve even tasted it. I’ve seen taste panels ascribe caramel-like flavor descriptors to pale American lagers with caramel food coloring added to mask the true color. Continue reading
One thing no homebrewer should be without is the Hop Variety Book (PDF) from our friends at HopUnion in Yakima, Washington. This wonderful book has information for dozens of domestic international hop varieties, including their alpha acid, beta acid, and essential oil content, and so much more including some decent aroma descriptors as well.
It’s understandable why bitterness is an acquired taste. Despite what surely must pain “iso-philes” (bitter beer lovers), the old “bitter beer face” commercials have some truth to them. It’s generally agreed that bitterness has been an evolutionary signal for a possible poison, so it’s no surprise if we are initially put off the taste of bitterness.
What’s not quite so understandable is how the sensation of bitterness differs for each of us. Much of the research I’ve been involved with has shown that various bitter compounds elicit different responses from each person, with few correlations able to be drawn. Each compound has different intensities and often different qualities as well, including harsh, medicinal, vegetative, lingering, etc.
The predominant source of bitterness in beer are the iso-alpha acids. These are derived from the alpha acids which are present in the flowers of the female hop plant, Humulus lupulus. These alpha acids are found in the lupulin glands of the flower, which look like tiny yellow pollen-like balls clustered together. Much of the other material in the hops which brewers value (such as aroma compounds) are also contained in the lupulin glands, but today we discuss the alpha acids.