Can you still drink red wine if it's sour?

Sometimes we cannot finish red wine in one go, so the remaining wine needs to be saved. Some people find that the taste of red wine is not as pure as before, but becomes a little sour, and they don’t know whether such red wine can still be drunk. In fact, there are many reasons that cause red wine to become sour, which require specific analysis. So, can we still drink red wine if it turns sour?

The main source of sourness in wine

1. Tartaric Acid:

The acid taste is not very strong, but refreshing and stable. It is generally the organic acid with the highest content in wine. The tartaric acid in wine comes from the grapes themselves, which are fruits with high tartaric acid content.

"Wine diamonds" formed by tartrate crystals

Most of the tartaric acid in wine exists in the form of tartrate, which is easily soluble in water but not in wine. It will crystallize and precipitate when exposed to low temperatures, forming so-called "wine diamonds" on the bottle wall, cork or bottom of the bottle. "Wine Diamond" to a certain extent indicates that the quality of this wine is more mature and stable, but it is only found in a very small number of wines.

2. Malic acid

It has a strong sour and stimulating taste, and has a certain fruity aroma. You can imagine the taste of a green apple. The malic acid in wine comes from the grapes themselves, which contain a certain amount of malic acid.

Malic acid: the sour taste of green apple

3. Lactic acid

The sour taste is relatively soft and delicate, not as astringent and irritating as malic acid, with a slight milky flavor, which is the taste of plain yogurt. The lactic acid in wine comes from the "secondary fermentation", which is also called "malolactic fermentation".

During this process, part of the malic acid is gradually converted into lactic acid, and the overall acidity of the wine decreases and becomes softer. Friends who like to brew their own wine often find that the taste of their homemade wine is sharp and not mellow enough. In fact, in many cases, this is due to the lack of secondary fermentation process.

Lactic acid: the sour taste of plain yogurt

4. Citric acid

It has weak acidity, a refreshing and smooth taste, and a fruity aroma. It is found in small amounts in wine and comes from the grapes themselves. To understand the taste of citric acid, think of it like eating a lime or a lemon.

Citric acid: the sour taste of lemon slices