In winemaking citric acid is reduced during normal fermentation and all but disappears.

it can be added to acidify wines and will give a freshness to the wine, HOWEVER it is important to note that it will give an artificial freshness if overused.  Because Citric Acid has a high degree of instability when added to wine, Tartaric acid is the preferred choice of additional acid in winemaking.

Craft brewers have occasionally used additions of citric acid to lend some tartness to Belgian-style witbier; although some tartness is traditional, it has historically been the result of lactic bacterial activity. 

Citric acid has also been used as a cleaning agent, particularly in the removal of “beer-stone” from fermentation vessels.

It is more commonly used as a final rinse aid after sterilising equipment.  As a final rinse add add 50gm to 10 litres of water and rinse barrels, equipment in this solution.  Used to clean distillilng columns and copper packing

availaible in 100gm sachet and 1kg packets