Rating a wine is not for experts alone. This skill can be developed by anyone with enough practice and exposure and it starts with understanding the elements in wine making and rating.
There are basically 4 areas where wines are rated. These are appearance, smell or aroma, taste, and aftertaste. Below is some information on how wines get their scores:
1. 6 star wines are exceptional vintage, so perfect that nothing more can be removed or added to improve it. Only less than 1% of the total worlds production of wine belongs to this category. They possess all the complex characteristics of a classic wine. They aren't usually sold online or elsewhere and tagged as collector's items.
2. 5 star wines are almost perfect because they have extraordinary organoleptic characteristics. These wines have balanced richness, color, and overall harmony so that they produce extraordinary texture, smell, and taste.
3. 4 star wines are 5% of the worlds production and they don't have noticeable flaws and they display high character, finesse, and flavor. These are the types of wine commonly collected today. They are expected to get a higher rating as they age.
4. 3 star wines are what they usually call average wines. They are made from ordinary ingredients but are soundly made. They are the same as 4 star wines in that they don't have noticeable flaws and they have excellent texture and taste.
5. 2 star wines on the other hand are below average. They contain noticeable flaws (ex. Floating particles, unpleasant odor, watery substance, etc) due to extra tannin or acid. However, they can be generally pleasant but lack complexity, depth, or character.
6. 0-1 star wines are usually homemade wines that don't make it to the wine market. These are commonly made from poor quality ingredients and they are noticeably dull. They are flawed, terribly diluted, and imbalanced.