In the identification of beer quality, we should pay attention to the following:
1. Transparency. Liquid looks clear and light, no suspensions, no deposit.
2. Color. The color of light beer should be light golden-yellow, stout should be dark brown. The identification in addition to directly observe with our eyes, a color value is used. Add a litter of iodine solution into 100 ml of distilled water making the color as same as the beer being identificated. The value of iodine solution is the color value. Light beer’s color value requires to be 0.35-0.6 ml, stout requires more than 3 ml.
3. Bubble. Foam has a special significance on the beer quality, it requires that bubbles rising when beer pouring into beer cup, bubbles looks delicate and white, cup-hanging, disappeared slowly (3-5 minutes).
4. The aroma and taste. Light beer requires the fragrance of hops prominent, stout smells a clear malted flavor. Taste a refreshing feeling, stout requires plus mellow and smooth taste.