Category Archives: Science of Wine

Taste & Tannins

When a grape moves from vine to wine, it undergoes a chemical process called fermentation. During this process, yeast eats the natural sugars in the grapes, producing a few byproducts: carbon dioxide, alcohol, and over 200 aromatic esters — organic compounds that are responsible for a wine's specific, unique aroma!

When you smell these aromas, your brain forms neurological connections that link the scent to existing memories: jasmine flowers, cherry plums, dark chocolate, apricots, and many more.

It's possible to like a wine's aroma without enjoying the flavor. This happens when your brain detects discrepancies between the smell and taste. For example, if a red wine smells like a plum but dries your mouth out, these sensations conflict and might be unpleasant. This dry-mouth phenomenon is caused by tannins, which are bitter and astringent macromolecules that occur abundantly in nature.

Plants create tannins to make themselves less palatable. If your mouth feels “coated” when you eat an underripe pear or plum, that’s because of the tannins in the fruit! The tannins in wine come from grape seeds and skins, which are often extracted before fermenting white wine varietals, which is why red wines tend to be "dryer" than white wines.

In the right quantities and at the right age, tannins can be smooth, velvety, and delicious, adding a layer of complexity to your wine. Tannins are also found in tea, coffee, and dark chocolate!

Temperature

Yes, the temperature of your wine does matter! But it may surprise you to learn that the stability of temperature is more important than the degrees themselves.

When temperature changes, wine expands and contracts far more than the bottle it's stored in. This causes changes in pressure, which can have a negative effect on wine: too much pressure, and some of the bouquet of aromas leaks out; too little, and the contraction of the liquid sucks some external air through the cork.

This brings in extra oxygen, which can react with alcohol to create acetic acid — also known as vinegar. Keeping the temperature consistent while storing wine can prevent this ebb and flow and keep your wine complex and delicious until you're ready to pop the cork.