You may hear the word “tannins” pop up while enjoying a bottle with friends or reading a wine review, but what are tannins?
Tannins are also known as tannic acid and are naturally occurring polyphenolic compounds found in plant materiel. They are in the leaves, stems, seeds, and fruit (usually the skins).
Plants use this astringent and bitter compound to deter things from eating them.
You may have experienced this bitterness if you ever have left a bag of tea in your cup for more than a few minutes. This is because tea leaves have tannins and they actually turn tea yellowish or brown when hot water mixes with them.
The properties of tannins make them both off-putting and very useful. Their chemical make-up allows them to react and bond in different ways with alcohol, water, and organic materials.
You may have heard of “tanning hides” in relation to leather. This is an actual process of beating hides with oak to cause a chemical reaction and to alter the texture and color of the hide to create leather.
What does it mean for wine?
When grape skins, seeds, and stems are left to ferment together the tannins are imparted and dry red wine or rose is made.
Remember that 99% of grape varietals have mostly clear juice inside, it’s the contact with the skins during fermentation that imparts the red or rose color in the wine.
Some grapes that make white wine, like Chardonnay, are left to ferment with more of their plant material and this imparts some bitterness. You may hear of Chardonnay having a bitter, “phenolic finish” and this is why.
Why are oak barrels a thing?
It was discovered long ago that oak has a high concentration of a certain type of tannins. Chestnut oak has been used for ageing wine, scotch, and whiskey because the barrel actually interacts with it’s contents.
Toasting the barrel before use will activate chemicals in the wood and when wine or spirits are stored inside, flavors like vanilla, coconut, baking spices, and dill can be imparted.
The grain size of oak allows for some alcohol to evaporate out, and oxygen to pass through. This oxidation “ages” the contents in the barrel.
The alcohol that evaporates is known as “the angel share.”
Large barrels have less contact between the juice and the inside of the barrel because much of the juice doesn’t touch it.
Small barrels mean more contact between the barrel and the juice inside which means faster aging and more imparted barrel flavor.
New, freshly toasted barrels, impart more flavor than barrels that have been used before.
Chardonnay is often aged in oak which is why it can have vanilla, coconut, and even butterscotch notes.
Some grapes varietals are naturally more tannic and require more aging to “soften the tannins.” Choosing the size and age of the barrels lead to different expressions.
Italian Barolo made from the Nebbiolo grape was aged in giant oak barrels for many years to slowly soften it. Decades were needed to get Barolo to the perfect place to enjoy.
These days fewer people have patience for the turn around time and have started using smaller barrels to speed up the process. Much to the dismay of the traditionalist.
Whiskey, Scotch, and Port are still known to age for decades in barrels and demand high prices for doing so.
Tannins And Food
Tannins love to search out and bind to other organic material. This is why red wine and meat are so delicious together.
Tannins love fat..
They bind to fat, help to wash it down, and cleanse the palate. The more fat the meat has, the more tannic a wine to pair with it.
Cabernet Sauvignon and Syrah (Shiraz in Australia) are legendary choices for steak and lamb.
Tannins and shellfish are a horrible pairing because they react with the iodine in the shellfish and create the taste of “metal tin can.”
This is why white wine and light rose are popular with oysters, shrimp, and lobster.
Ordering the “surf and turf” and a bottle of Bordeaux may sound like a baller move, but the lobster will not play well with the Cabernet Sauvignon or Merlot’s tannins. Better to order a Pinot Noir or bottle of champagne in this situation.
Now that you know the slightly bitter truth about tannins you’re ready to choose a wine for your next BBQ or dinner party. If your dinner party is vegan and you have no fats, look to wines like Pinot Noir, Gamay, or Tempranillo if you are feeling a red. These wines are less tannic and won’t crush the food as a Cabernet will.
Happy exploring! Cheers!
