During FERMENTATION, yeasts convert the natural sugar in grapes to alcohol (also known as ETHANOL or ETHYL ALCOHOL) and CARBON DIOXIDE. The riper the grapes, the more sugar they contain and the higher the potential alcohol content of the wine will be. Wines with low alcohol (German rieslings, for example) are LIGHT-BODIED. Wines with high alcohol (many California chardonnays) are FULL-BODIED and almost CHEWY. When a high alcohol wine has too little FRUIT and a low ACID content, it tastes out of BALANCE and gives off a HOT or slightly burning sensation in your mouth.