Step 1: Appearance
Good wine should be clear. Some wines do have tartrates, but won’t be hazy. Exception will be natural wines, which has no fining or filtering during winemaking.
TIPS: Orange usually means the wine is oxidized, which is common in old vintage. However, do pay attention if the vintage is new. Legs mean high alcohol, more likely full body. But doesn't indicate the quality of the wines. Try Burgundy.
Step 2: Aromas
Aromas of wine classified into primary fruit driven, floral, herbal type; Oak, yeast or butter type of aromas tells you about the winemaking. And finally some developed flavor of more complex ones like, leather, mushroom, honey or nuts.
TIPS: Identifying aromas need practices. And the wine you can easily identify the main aroma is intense and identifiable, which means a positive quality.。
Step 3: Flavors
Normally flavors are similar to aromas, but do try to feel the wine in your mouth, whether it is strong and fine, or it has unpleasant rough and bitter taste.
Some prefer the astringent and chewy mouthfeel, but the good one will have it in a pleasant way.
Step 4: Structure
It is the most important element when judging the wine quality. Good wine should have good acidity, tannin, strong aromas & complex flavors which help the wine to be enjoyable for a period of time.
TIPS: Acidity is not sour taste, but the mouth watering capability, thus even sweet wine like Riesling can be high acidity. Tannin is the mouth drying sensation that only present in red wines.
Step 5: Finish
This one is tricky, as most people will mistaken the finish to be the acidity or tannin, but those do not count as finish. Good wine will have its primary flavor last as long as the acidity or tannin in your mouth and would not just simply fade away quickly.
Step 6: Preference Vs Quality
Sometimes even the best quality wine might not pleased you. Knowing what you like is more important to find the right one. Fruity, bold, fine, oaky or yeasty, you should always pay attention what type of wine makes you keep pouring from the bottle, that probably is your favorite.