Fruit is mainly composed of water and sugar, and it also contains other elements such as organic acids, dietary fiber, vitamins, and minerals. Lately, more and more grocery stores are displaying the Brix level of fruit. The Brix level could be considered one way to indicate how delicious something is. But did you know that when you eat a delicious fruit, in addition to the sugar, the acid is a major factor contributing to its delicious taste.
Of course nobody wants a highly acidic fruit that is too tart, nor a fruit that is only sweet. A truly delicious fruit is a fruit that contains a proper amount of acid, with well-balanced sweetness and tartness.
The balance of Brix and acidity has recently gained attention as the "Brix-acid ratio."
Fruit has a very small amount of acid compared to sugar. For example, a mandarin orange has a Brix level of approximately 11% but only about 1% acidity. Tartness, however, has a very strong influence on taste. When eating a mandarin orange, it can be very sweet, a little tart and delicious, or very sour and hard to eat. The difference between these is determined by a miraculous balance between the Brix level and acidity. Let's use a lemon as an example. The Brix level in a lemon is close to 10% at the most. This Brix level is higher than a tomato and closer to the Brix level of a strawberry. Lemons, however, are never referred to as "sweet," only as "tart." This is because of how high the acidity is. A lemon's acidity is usually over 4.5%. In comparison to the balance of the Brix level and acidity of other fruits, lemon has a very high acidity and is the definition of "tart."
Now, what exactly is a "delicious" Brix-acid ratio?
Brix level / Acidity = Sweetness rate (Brix-acid ratio)
Since the average Brix level is different depending on the kind of fruit, the Brix-acid ratio that is considered "delicious" depends on the fruit. Also, people have different taste preferences, so rather than an absolute value, the "delicious" Brix-acid ratio is usually expressed as a fixed range.