This week, our wine geekery will cover territory that might already be familiar to those who are more drinkers rather than makers of wine. Perhaps you’ve heard of them, but aren’t quite sure of the full definition. Perhaps you’ve got a vague grasp of this stuff but it’s confusing and you’d love to know more. Perhaps you already know all this stuff and want to read through this as a self-administered pop quiz. All approaches are welcome!


The architecture of tannins and acidity in a wine that gives it its figurative shape, which supports the aromas and flavors. Wines that have a great deal of structure are often best served aged, to give the tannins etc. time to mellow. Red wines get more of their structure from tannins; white wines gain most of their structure from acidity.

At Emeritus, we usually age our reds at least two years before releasing them so the structure is more balanced with the other qualities of the wine when poured.


If a wine has insufficient structure (meaning not enough acidity and/or tannins), it is considered “soft.”


When the structure (the tannins, etc.) of a wine blends in seamlessly with aroma and flavor.


Cork taint is caused by a chemical compound called TCA that gets into the wine, mainly from contaminated corks but also potentially via contaminated equipment. The chemical is a by-product of fungi, mold, or certain bacteria in cork tree bark when they have come into contact with certain fungicides and insecticides. It can also occur when bleach reacts with lignin, a compound that occurs naturally in wood, and the results are converted into TCA by yeast or bacteria.

This makes the wine smell and/or taste like wet cardboard, wet newspapers, or wet dog. When you see people sniff the cork of a freshly opened bottle of wine, that’s what they’re smelling for. The best way to learn to identify this is, unfortunately, practice. (Read more about cork taint here.)

Residual Sugar

Any sugar content (see also: Brix) that remains after fermentation ends. Residual sugar is measured by grams of sugar per liter (g/l), and wines are generally considered sweet if they contain more than 45g/l.

Tannic / Tannins

Found in the skins, stems, and seeds of the grapes, tannins give body and complexity (structure) to the wine. Some grape varietals, such as Cabernet Sauvignon, are naturally more tannic than others. Aging in new oak barrels can also contribute to structure, as tannins are absorbed from the wood, but too much can impart bitterness.

When tasting, tannins present as a dry-mouthed feeling.


Potassium bitartrates, also referred to as “wine diamonds” for their crystalline appearance. Tartrates are formed from naturally occurring tartaric acid in all wines and provides structure, balance, and flavor. When a wine is chilled to temperatures below 40 degrees, tartaric acid will bind with the naturally occurring potassium in the wine to form these itty bitty pretty deposits. (See also: Sediment.)

Tartaric acid is one of three main acids found in wine grapes, alongside malic and citric acids. Each plays a role in vinification, and contribute different flavor profiles and textures to the final wine.


If the sides of your mouth water after a sip of wine, or the sides of your tongue react the most as you savor the taste, that’s acidity you’re reacting to. Acid helps preserve and keep the wine fresh, and too little acid can unbalance it into having a “flabby” mouthfeel. High-acid wines pair extremely well with food, like our Hallberg Blanc with seafood or Pinot Hill with red sauce.


This is what happens when wine is exposed to oxygen, which ages the wine. It strips the fresh, fruity flavors and replaces them with cooked fruit or nutty flavors.

At the end of the day in the Emeritus tasting room, we top open bottles off with a puff of argon gas (which is heavier than oxygen and thus gets between it and the wine to prevent oxidation overnight) and put them in our wine fridge. At home, if you don’t finish that bottle of red before the end of the night, even just corking and putting the wine in the fridge can help slow oxidation to a certain extent.


Most common in red wines, this is the stuff at the bottom of your glass after the last pour from an older bottle. This happens even if the wine has been filtered before bottling. It’s harmless, just the solids in the wine (tannins and tartrates) that have clumped together until visible, but it doesn’t taste particularly good.