A blend of acids (Citric , Malic  and Tartaric )  used to increase the acid in wine making  to balance the mouthfeel

per 100gm 

It is typically used in wines and meads  that are naturally lacking in acid, which can result  in a flat tasting wine. 

Doseage rate is usually only a few grams per 5 litres.  

Acid Blend adds liveliness to the wine or mead and helps to bring out its fruity flavors.  Before you add any acid to a wine you should first check its acid level with pH strips or an acid test kit.

Directions:
Before Fermentation: Dissolve the required amount of Acid Blend directly into the wine before the yeast is added. Titration readings taken with an Acid Testing Kit should be about .55% tartaric for a proper fermentation. Readings taken using pH strips should be about 3.8-3.4. 

At Bottling Time: 
Sometimes wines will not taste their best, even when they are at their optimal level of acidity and may require a slight final acid adjustment to taste. This also depends on the wine’s character and your personal taste. To accomplish this, first, put measured amounts of Acid Blend, in a quart sized sample of your wine. If you add too much to your sample, blend it back into the batch and pull a new sample. Once the dosage is established, add that dose to the entire batch.