Here’s a pointer on how to deal with mint leaves and why. I did some real research a while back and documented several things about mint and bitterness.
Virtually everyone (greats in the bartending field included) parrots the same misinformation that “chlorophyll is bitter”.Chlorophyll is not bitter.
DO NOT MUDDLE, BLEND, OR SHAKE THE MINT LEAVES.
Why? The Science:
Mint’s “Mintiness” lies in the small oil gland hairs called trichome (also see indumentum) growing from the surface of the underside of the leaf, and not from within the interior of the cell walls where all of the bitter flavors of the plant are located (in mint family the leaves are covered in fine trichome hairs or indumentum, which contain the essential oils.). It is during the rapid growth phase that the most mint is available. Once max growth occurs mint oil levels quickly decline from their peak. Mint has a variety of uses. The plant is usually steam-distilled for its oil which is located in glands on the undersides of the leaves. The oil is used to flavor a variety of foods such as gum or candy and is also used in perfumes, cosmetics and health care products. Chlorophyll itself (the green molecule found in plants that absorbs sunlight during photosynthesis and converts it to energy) is not bitter or bad for you, though that is a commonly held myth among bartenders. Also, according to WebMD “People use chlorophyll as medicine, so chlorophyll may even be desirable in a Mint Julep, were it not for the tannins and other bitter compounds. Common sources of chlorophyll used for medicine include alfalfa, algae, and silkworm droppings. Chlorophyll is used for bad breath and reducing colostomy odor. Chlorophyll is also used for constipation, ‘detoxification,’ and wound healing.”
So while the Chlorophyll may add a nice green, it doesn’t taste bad, and can’t hurt the drink – it is the other parts of the cell interior that will add bitterness; likely the Tannins known to be found in Mint Leaves. Tannins, a group of alcohol soluble bitter and astringent compounds, can be found abundantly in nature. They’re present in the wood, bark, leaves and fruit of certain plants (and in the twigs of certain trees, specifically Chestnut and Oak trees).
If chlorophyll itself were bitter then Sweet Peas would be bitter, and they’re not. If you crush the mint leaves, you unbalance the flavors in the drink; adding more sweetener only masks it. The longer the Tannin leaks through the crushed and ruptured cell walls the more bitter the drink becomes, and this happens rather quickly.
Site Author, David J. Curtis: David Curtis, a seasoned professional with decades of bartending and bar management experience began his career in Midtown Manhattan, NY, tending and managing bars before diving into Manhattan’s bustling nightlife club scene. Over the years, he has mastered high-volume, high-pressure bartending as the lead bartender in iconic Midtown clubs and tended bar briefly in the Wall Street area, generating over $1,350,000.00 annually in personal drink sales. He has since extended his expertise to establishments in Georgia and now Tampa in Exclusive Platinum Service Awards Clubs, Florida. David’s roles as a Bartending Instructor at the American Bartending School in Tampa, while maintaining a second job bartending, and his years experience of managing bars, and working as a Brand Ambassador along with his extensive professional library of over 1,000 bartending books, highlight his dedication to continually refining his craft. He holds a diploma in Bar Management and is BarSmarts certified by Pernod Ricard.
