Acids in wine ripened grapes. While concentration varies among grape varieties, it is usually found in higher levels with red wine grapes. The acid is created as a byproduct of the metabolization of nitrogen by yeast cells during fermentation. The combination of succinic acid with one molecule of ethanol will create the ester mono-ethyl succinate responsible for a mild, fruit aroma in wines. Acidity is highest in wine grapes just before the start of "veraison", which ushers in the ripening period of the annual cycle of grape vines. As the grapes ripen, their sugar levels increase and their acidity levels decrease. Through the
Content (measure theory) any compact "C", λ("C") is the inf of λ("D") for compact sets "D" containing "C" in their interiors. Content (measure theory) In mathematics, a content is a set function like a measure but a content need not be countably additive, but must only be finitely additive. A content is a real function formula_1 defined on a field of sets formula_2 such that An example of a content is a measure, which is a "σ"-additive "content" defined on a "σ"-field. Every (real-valued) measure is a content, but not vice versa. Contents give a good notion of integrating bounded functions on a