Dethroning L-Theanine
Okay, maybe we're not fully dethroning the famous savory amino acid known as L-Theanine, but I think it's about time this became a constitutional monarchy.
I have written at length about this amino acid. It is often credited, for good reason, as the source of matcha's unique savory, brothy quality. But, flavor is complex, and so is tea.
To me, the attribution of the taste of "umami" to a single molecule reminds me a bit too much of the oversimplification that has happened throughout the history of nutrition science. Look up the nutritive value of, say, tomatoes and you find ample mention of vitamins and fiber, but what about the benefits of the carotenoid Lycopene? Look up broccoli, and where is anyone talking about the phytochemical Sulforaphane? These compounds are powerful, with effects on brain function, skin health, hormones, the microbiome, and more. All of this is to say, a reductionistic approach to understanding the chemical composition of natural food products just does not align with reality. There is nothing on earth quite so powerful at synthesizing new molecules than plants - so is it really feasible that the savory flavor in tea boils down to one simple amino acid?
No way. Let's look at some of the other unsung heroes I'm discovering that make matcha taste so brothy, sweet, mouthwatering and captivating.
2,4 - Dihydroxybenzoic Acid
2,4-DHBA, for short. This is a byproduct of shading. When tea leaves are under stress (as shaded leaves are), they produce extra 2,4-DHBA as a protective mechanism against possible pathogens. The thing is 2,4-DHBA isn't just protective, but has been associated with flavor changes in the tea itself. In particular, this molecule is known to lend a sweet aftertaste - something known in Chinese tea culture as "Hui Gan," or "Returning Sweetness." A tea may start out tasting bitter, but that bitterness transitions into a sensation of having just eaten something sweet - a sensation that makes you want to keep drinking. This adds to the overall "roundness" of a tea, it's Kokumi character (if you read my most recent post), and enhances the mouthwatering aspects of umami.
Dimethyl Sulfide
This one's called DMS, for short. Another compound in shaded teas is Methionine. During processing, Methionine breaks down into Methional, which then further breaks down into DMS. All of these are sulfur-related, volatile compounds - not tied to the amino acid content of the leaves. DMS is known to have more of an effect on the scent of the finished tea. It is strongly linked to the "shaded aroma" of tea (known as "Ooika"), which often comes across as notes of seaweed and ocean brine. When paired with L-Theanine, it enhances the overall sensation of umami, and is generally seen as a mark of particularly high-grade shaded teas, as it makes the flavor profile richer and more complex overall.
Why does this matter?
Beyond just being interesting for chemistry nerds, there's some real-world significance to an awareness of these two compounds. It all comes back to that old refrain of mine - modern conventional tea farming is a problem!
In the pursuit of L-Theanine, farmers have gotten really good at dumping chemical fertilizers into their soil to maximize the production of this one molecule. But guess what happens when they do this?
The two compounds mentioned above, 2,4-DHBA and DMS decrease with conventional farming practices. It has been found that organic teas have about 4 times more DMS than conventionally-farmed teas! It is supposed that this is a result of the heavy pesticide use in conventional farming, as DMS is one of several compounds the plants form in order to defend themselves from natural pests in the absence of synthetic help.
The story is similar with 2,4-DHBA, which I mentioned above is also a compound the tea leaves produce to defend against threats, in particular pathogens and fungus. With the heavy use of pesticides and fungicides in conventional tea farming, the tea leaves have less of a biological need to produce this tasty compound.
I'll note that the heavy fertilizer requirements needed to produce L-Theanine-laden teas almost always lead to heavy pesticide use. The leaves become more appealing to insects when they are fertilized in this way, and so must be more aggressively protected.
Consequently, we come back to what I've been noticing again and again. In the pursuit of L-Theanine driven, umami-loaded teas, we lose out on complexity. Let's not do that anymore. Our partner farmers share our philosophy on this matter. Here's hoping one day they won't represent the minority of tea farmers in Japan!
Thanks for reading and happy sipping,
Simon