Wine tasting is a sensory technique for figuring out the elements in the wine as well as its quality through vision, sniffing, and tasting. The tasting technique consists of four stages: 1-Appearance: vision, 2- Aroma: sniffing, 3- Flavor: The first stage of sensation (tasting), and 4- Finish: The second phase of sensation (tasting).

The sniffing process includes two stages. In the first stage, wine gets swirled in the glass, and with a bunny sniff, the taster finds out whether or not the wine is in good condition. At this stage, it gets realized if the wine is good-to-go or if it's oxidated or rotten and needs to get thrown away.

More Info: winefolly.com