Residual sugar is the level of sugar left-over in the wine after fermentation. This is rarely spontaneous, most often it is the winemaker’s choice to stop the fermentation prematurely and keep a bit of the sweetness in wine. Residual sugar is often misunderstood and confused for fruitiness. The way to assess it is by focusing on the actual flavour of sugar on your tongue, not the sweet fruit aromas on your nose.
Tannin is a compound in wine that mostly comes from the skins and stalks of a grape, so it is most evident in wines that have been macerated with the skins and stalks. White wine doesn’t go through maceration, so tannins won’t be present. In wine this feels as the drying, slightly bitter feeling on your gums. To assess it, focus on that feeling, the higher the intensity, the higher the tannin level.
Body is how we assess the weight of the wine. The best way to assess it,
is by comparing it to water. If the wine feels as light as water, it is a light bodied wine, if it feels slightly heavier then it is medium-bodied and if it feels very heavy then it is full-bodied. There are parallels with alcohol content and body, but it’s not one hundred percent reliable, so always double-check your results.
Acidity is the level of PH in the wine and it is best described as the mouthwatering effect that occurs on consumption. The level can be assessed by taking a sip of wine, swirling it around your mouth, swallowing and then tilting your head forward with your mouth slightly opened. You will feel saliva building up and the speed and volume will determine the level of acidity in the wine. High acidity would be equal to taking a bite of a fresh lemon and low acidity would be eating cooked mushrooms.