How to blend red wine

I used to work in a bar, and I didn't know how the specific operation process was blended, but my bar supervisor told us something.

First of all, there are high and low grades of fake red wine, and the low grade is the kind that is easy to taste. If you do that, it's meaningless, and I won't say much. There is also a high-end point, that is, the main ingredient is red wine, just adding a part of the rest to make a profit in quantity. This kind of wine mostly appears in middle and high-grade fake wine.

Main raw materials: alcohol, syrup, purified water, red wine, preservative, pigment and flavoring agent (one seems to be sour).

Note that the blending ratio should not be too large (at least 60% pure red wine)

First, make these things into a liquid with almost the same taste and color as red wine. The step of blending is not to add things to red wine at once, but to slowly add red wine to these liquids, and then to a certain extent (master it yourself) and then fully blend.

These are all said by the supervisor, and I haven't done them. Feel for yourself how to operate them.