Wine, Alcohol, and Ethanol

the Chemistry of Wine

Wine is, at its root, about a yeast taking the sugar it finds in grapes and turning that sugar into alcohol. The grape has a few other items in it that add flavors, but most of it is water. Grapes are around 80% water and 20% sugar. So once the sugar is fermented during the winemaking process, you end up with water, alcohol, and flavorings.

The actual type of alcohol created by the yeasts is ethyl alcohol, or ethanol. The chemical symbol for ethyl alcohol is:


This is the type of alcohol found in all drinks. The other two main types of alcohol that exist - wood alcohol and rubbing alcohol - are both poisonous to drink.

Alcohol is one of the four energy sources of the human body along with carbohydrates, fat and protein. If you study how wine is metabolized, you learn that the liver converts the alcohol into acetate, which the body burns for fuel. The body creates 7 calories of energy per gram of alcohol.

Besides water and ethyl alcohol, what else is in wine? Here is a sample breakdown of a large glass of wine:

Water: 250g
Ethyl Alcohol: 25g
Glycerine: 3g
Pectins: 1g
Acids: 1g
Polyphenols: 500mg
traces of flavor elements

Note that these are all rough guesses. With a total weight of 250+25+3+1+1+.5 = 280.5g, and alcohol being 25g of that, that is an alcohol percentage of 9%. Some wines are higher, some are lower. So this is a general estimate of a random glass of wine.

Water is great with 0 calories and 0 carbs.

Ethyl alcohol brings in calories (at the rate of 1.6 x percentage alcohol per oz) and 0 carbs.

Next comes glycerine, which is what some systems count as a "carb". Glycerine is commonly used in candy bars to keep them soft and chewy. It's not a fat, a protein OR a carb - it's a "trihydric alcohol". Glycerine is a byproduct of fat that burns at about the same rate as carbs, but doesn't raise the blood sugar level much.

Pectins are gooey substances that in essence let things have substance, like in jelly. It is a dietary fiber and really isn't digested by us humans.

Acids are chemical compounds with a pH of less than 7, that gives foods a sour taste.

Polyphenols are the coloring agent, which among other things are antioxidants.

So, nutritionally, it is the alcohol in the wine that is primarily going to affect your diet and how you metabolize it and other things you eat at the same time.


A great deal of research and work went into my wine / health pages. If you use this information, please credit me properly. Thanks!

Wine and Health

All content on the WineIntro website is personally written by author and wine enthusiast Lisa Shea. WineIntro explores the delicious variety and beautiful history which makes up our world of wine! Lisa loves supporting local wineries and encouraging people to drink whatever they like. We all have different taste buds, and that makes our world wonderful. Always drink responsibly.