Have you ever wondered, what makes up the taste of tea? And what kind of substances make one tea taste better than the other? At first let‘s analyse what makes up the sensations that we feel when we take a sip of tea.
We rarely understand, which part of the experience is the taste, and which – the aroma. We often experience aroma as part of taste. But tastes are actually only five: sweet, sour, salty, bitter and hot. Some add a sixth taste – umami, that is difficult to describe. Some explain it as a feeling of „tastiness“, some just say, that it is a reaction of our receptors to a specific amino acid. Some argue that it is not a separate taste, others also claim that hot is also not a taste, but rather a burning feeling on the tongue. However it may be, there are only several qualities of taste, and everything else is just various combinations.
Aroma lifts the experience to a whole other level. In tea, non-volatile compounds make up the taste, and volatile compounds make up the aroma. There is a huge variety of volatile compounds, and usually we use their spectrum to distinguish one sort of tea from another and evaluate the quality (if, let‘s say, we taste or smell the tea without seeing the tea leaves). Two teas can have the same proportions of, let‘s say, sweet, bitter and sour, but the aroma will let us know, which of them is black, and which, for example, is dark oolong.
It‘s important to talk about the third factor, which is mentioned by tea experts. It is a feeling of texture that stays on the tongue when you taste the tea. It can be dryness, roughness, or the opposite – softness and roundness (a kind of „velvety“ feeling). These sensations can be compared to the ones that you feel when you touch some kind of fabric. The better the quality of the fabric, the more pleasant the experience.
Main biochemistry in tea
So, what chemical substances create these three aspects – taste, aroma and texture? Actually, it‘s a variety of different substances:
- Polyphenols – organic compounds, that create bitter and dry sensations. Some polyphenols, for example, thearubigins, give tea a deep red colour and enrich the taste, making it deeper and more complex. The more thearubings the tea has, the better quality – it‘s colour will be deeper and more pleasant to the eye, and the taste will be fuller. But other polyphenols create an unpleasant drying feeling in the mouth, and if this characteristic will be the main one, the tea will seem cheap and of low quality. Caffeine is also one of the polyphenols, and it creates bitterness and astringency.
- Amino acids. They are important to both taste and aroma. There are several dozens of amino acids in tea. Some of them make tea sweeter, others create umami taste. Most of them not only enrich the flavour of tea, but also have positive effects for our bodies – calm the nervous system, regulate blood pressure. So high quality tea not only has the chemical substances that create a richer flavour and aroma, but it is also beneficial for us. That‘s why after drinking high quality tea we feel differently than after cheap tea. The amount of amino acids is one of objective criteria used in studies to determine the quality of tea. Two most important amino acids are theanin and GABA (gama amino butyric acid).
- Pigments. Those are carotenoids, chlorophyll and other pigments. They not only create colour – they also influence taste, aroma and quality of tea. While the leaf is fresh, the green colour of chlorophyll dominates over orange component of carotenoids, which can be seen in fermented teas. Chlorophyll gives the „grassy“ taste, which is more expressed in green teas. Some people enjoy that, some not. Carotenoids make up a part of the colour and aroma of fermented teas. They also have benefits for our bodies – they protect from atherosclerosis and heart disease and also regulate our immune system. Carotenoids create aromas that remind us of ripe fruit, roses, tobacco, rum, various berries. These aromas enrich the experience of the tea and its quality.
- Minerals. Tea has small amounts of minerals that create the so called „mineral“ aftertaste in tea. This aftertaste can be found in some teas, but not all tea drinkers enjoy it. Wu Yi oolongs are probably best known for their mineral aftertaste, which is usually associated with the soil that the tea plant grows in.
- Carbohydrates. The tea leaf has glucose, fructose, sucrose, raffinose and stachyose. They make up for the bigger part of the sweet taste in tea.
- Volatile (aromatic) compounds. The aroma of tea is a huge factor in tea quality. If we take the rich aroma away, we lose the bigger part of the experience. There are more than 600 volatile compounds found in tea, so you can imagine the vast variety of aromas and their combinations. The volatile compounds are various alcohols, aldehydes and lactones, that are created from saturated acids. Aromatic compounds in tea are strongly determined by the growing location, the tea bush varietal and the production process, so they strongly influence the quality of the tea.
If you want to read more about biochemistry in tea, i would recommend you reading this article: http://en.craneandpine.ru/tea-biochemistry.
So you can see that the taste and aroma of tea are made up from so many different chemical compounds. It‘s interesting to note that the ones that make tea taste more pleasant, are also the ones that benefit our health and how we feel. So if we buy a high quality tea, it is benefiting not only our senses but also lifting our mood, regulating our immune system and calming our nervous system.
If you want to book a tea tasting to get to know high quality tea, you can read more about it and contact with me here: https://teagong.lt/en/degustation/.