Vertical and horizontal tasting involves a range of vintages within the same grape and vineyard, or the latter in which there is one vintage from multiple vineyards. "Banana" flavors (isoamyl acetate) are the product of yeast metabolism, as are spoilage aromas such as "medicinal" or "Band-Aid" (4-ethylphenol), "spicy" or "smoky" (4-ethylguaiacol), and rotten egg (hydrogen sulfide). Some varieties can also exhibit a mineral flavor due to the presence of water-soluble salts as a result of limestone's presence in the vineyard's soil. Wine aroma comes from volatile compounds released into the air. Vaporization of these compounds can be accelerated by twirling the wine glass or serving at room temperature. Many drinkers prefer to chill red wines that are already highly aromatic, like Chinon and Beaujolais.
Most food has its origin in plants. Some food is obtained directly from plants; but even animals that are used as food sources are raised by feeding them food derived from plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock.