My brother’s girlfriend and fellow booze hound, Shannon — who sent me the link that inspired my Ramos Gin Fizz — sent me a message this morning. She and some of her friends recently had a tasting, to talk a little bit about “breathing” and “bruising.”
Here’s the thing. She goes to Yale. And she’s a scientist. So here’s a really cool super-scientific rundown on the odors in your favorite liquors!
And while this an excellent read, I will offer you a sorbet, if you will. A palette cleanser before we head into the science.
Thanks to Shannon for writing this up and sending it to me!
“Most odors are relatively small organic compounds. (Organic in this case is a Science Word that means composed of carbon, hydrogen, nitrogen, oxygen, and sometimes a few other elements).
“Any complex mixture of odors is generally divided into three parts: top note (in perfume aka head note), middle note (heart note) and base note or fixative. The physical/chemical characteristic that corresponds to this classification is vapor pressure, sometimes expressed as volatility. Odors with a high vapor pressure (more volatile) are in the top notes, those with the lowest vapor pressure are fixatives. Imagine the odor being contained by a piston. The more the odor wants to evaporate and escape, the harder the piston has to work to contain it.
“Sometimes, fixatives actually interact chemically with the higher notes to lower their volatility and slow their release. This is especially common in perfumes.
“In red wines, for example, the top notes are sometimes terrible and offensive. They might contain sulfuric or amine groups that generally evoke the sensation of spoilage. So, we let them breathe for at least 30 minutes to get rid of these. Some people use aerators or decanters to speed the process. The wine aerators work exactly like the aerator on your kitchen sink. They increase the surface area of the liquid that comes into contact with air. In your sink, this removes the chlorine taste from tap water.
“In gin, on the other hand, the most distinct and pleasing odor is the juniper, which is the top note. (The quality of juniper actually doesn’t come from a single compound but rather a mix of lightweight alcohols.) Agitating gin causes some of the juniper odor to evaporate right away (bruising), and the rest of the drink contains only middle notes and fixatives. Yuck.
“Likewise, white wine’s flavor comes mostly from the green compounds in the top note, and we refrigerate it to keep them in as long as possible. (Hexenal, for example, smells like grass — very common in white wine).
“Scotch and whiskey have a super complex odor bouquet, generally. That’s a whole odor/taste thing on its own.
“Vodka ideally doesn’t have any top or middle notes (unless it’s flavored), so shake away, Mr. Bond.
“Almost all liquor contains some organic compounds that become spoiled or rancid in sunlight. That’s why the bottles are amber-colored and should be stored out of direct light.
“I have a big list of compounds found in wines and beers and what they smell like from a tasting I did. We compared some pure compounds to wines and beers that really feature them. There is a surprising amount of cheese odor–this is why you pair some wines with cheeses. Some of them are also found in whiskey–the campfire odor, for example, comes from a single compound, guiacol.”
Hope you guys found it informative! Thanks again to Shannon for helping out and all the info!
Always a pleasure!