1, see: take a bottle of red wine, do not open, with the following methods to see the good and bad of red wine: the bottle of red wine upside down, tilted at a certain angle, facing the sun or light to see the bottom of the bottle whether there is more sediment and residue, if too much of this wine is a problem, if there is no or a small amount of transparent sediment is normal (red wine in the long term in the process of fermentation, the production of tartaric acid, which will produce tartaric precipitation).

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2, with a small flashlight or cell phone flashlight developed to the bottom of the bottle, the light directly through the bottle, cleaning to see the transparent red light, the quality of red wine is not a problem, if the light scattered, can not be cleaned through the bottle of red wine, the wine has probably deteriorated, can not drink.

3, open the red wine, poured into a red wine glass, see if it is clear, such as turbidity, do not drink, even shaking the cup to see the wall of the glass of wine, uniform downstream, the more viscous the wine the slower the flow rate, the better the quality of the wine, the image of the French people compared to the "lover's tears", also known as the hanging cup, some people use this to determine the quality of the wine is not correct, this can show that the wine is good or bad. This is not correct, this can explain the viscosity of red wine and the high and low alcohol.