Of the thousands of chemical elements that compose a typical tobacco leaf there are a few that take primary responsibility for the taste and aroma of your smoldering stogie. Some of the more important elements have been identified as members of the carotenoid family.
Carotenoids are the pigments which give many vegetables and flowers their color. The obvious example is that belicoso-shaped delicacy known as the carrot, from which the word carotenoid derives. Carotenoids give that root its orange color. In other cases the carotenoid content is masked by green chlorophylls, but as the fruit ripens and the chlorophyll content decreases, the colorful carotenoids emerge. This is what happens when a green tomato turns red on the vine.
The process of ripening is really just the early stages of decay — the constituent elements of the fruit, or in this case the leaf, are breaking down and releasing new and more organoleptically interesting compounds. Carotenoids are highly sensitive to oxygen, light, and temperature, and all of these things are carefully controlled by the tobacco grower as the crop is grown, harvested, and particularly during the curing and fermenting stages.
The major carotenoid pigments in tobacco are lutein, beta-carotene, moxanthin and violaxanthin. As these carotenoids break down via oxidation, aromatic derivatives are formed which are crucial and distinctive to the crop. For the sake of example, we can take one of these pigments, lutein, and look at some of its derivatives.
Lutein is found in leafy green vegetables, most prominently in spinach and kale. (And yes, tobacco too.) It is important nutritionally, but for our purposes here we are most interested in what happens when it degrades. Lutein breaks down during the air-curing process to several ionones and their derivatives, such as Beta Damascenone and Megastigmatrienones, two of the carotenoid derivatives which are most responsible for the smell of tobacco.
Beta Damascenone is one of the rose ketones and is considered to be the marker for quality rose oil, even though it is present in extremely small quantities. For whatever reason, the human nose is very sensitive to this smell and very little is needed to detect it. Interestingly, it is found in beer, and is responsible for some of the floral notes in red wine (especially merlot.) In addition to its floral nature, beta damascenone is also associated with the smell of baked apples. It is not present in fresh apples, only baked. Other descriptors:
Closely related to the damascenenones (and damascones) are the ionones; in fact, they’re all part of the rose ketone group. Ionones are present in almost every type of perfume, and are almost always described as woody with strong violet accents. Both alpha and beta ionones have been identified in cured tobacco leaf.
Don’t ask me how to pronounce it, but megastigmatrienones is arguably the smell of cured tobacco. Its four isomers have been isolated or synthesized and used in commercial applications to impart or “improve” the smell of tobacco and to cover up other unwanted odors. (It is available commercially as “tobacco cyclohexenone”.) It is sometimes held responsible for the note of tobacco that is often detected in full-bodied red wines. Most frequently the aroma of megastigmatrienones is associated with the following:
- sweet tobacco
- dried fruit
Other interesting carotenoid derivatives found in cured tobacco are theaspirone, an ingredient in black tea and a component of tea essential oil, and beta-cyclocitral, which is described as green, grassy or hay-like.
Many cigar enthusiasts have detected flavors like these at one point or another. Floral, honey and tea-like notes I find most often in milder cigars, usually with shade wrappers. And while these are just a few of the elements from only one group of the many compounds that contribute to the flavor and aroma of cigar tobacco, I hope it shows that notes of tea or grass or violet are not out of the range of possibility for some experienced cigar enthusiasts.
So if you find yourself musing over the soft wood and floral notes of that ’02 Choix Supreme and suddenly detect a hint of honey, consider yourself fortunate… not crazy.