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
Seibel grapes or two of Albert Seibel’s grapes together and name their creations after themselves, e.g., Seyve-Villard 5276 (“Seyval Blanc”). Seibel grapes Seibel grapes are a group of wine grape varieties which originated with the work of Albert Seibel crossing European grape with American grape species to increase disease resistance. They were planted widely in France during the 1950s but have seen decline in recent years because French wine law proscribes hybrid grapes in appellation wine. The grapes are still commonly used as blending grapes in table wine and mass commercial wines. New Zealand, England, and Canada also have plantings of Seibel