Frying batter (pâte à frire) is a crêpe-like batter that is used to enrobe food that is being deep-fat fried. It must be used the day it is prepared or the yeast in the batter will cause it to ferment. It is most commonly used for vegetables (such as zucchini, onions, eggplant, salsify), fish and crustaceans (fillet of sole, shrimp), certain meats, particularly offal, and for fruits, as for beignets. For optimum taste, the batter should be light, creamy, and very smooth. Beer is used most often as the liquid, as its yeast content causes the batter to swell during frying, which makes a very attractive presentation. All items to be battered and fried must be perfectly cleaned, trimmed, and dried before being dipped into the batter, and they must be completely coated. Once fried, the item should be drained on a double layer of paper towels and served immediately, as it will quickly begin to lose its crispness.