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.
A negative-calorie food is food that supposedly requires more food energy to be digested than the food provides. Its thermic effect or specific dynamic action – the caloric "cost" of digesting the food – would be greater than its food energy content. Despite its recurring popularity in dieting guides, there is no scientific evidence supporting the idea that any food is calorically negative. While some chilled beverages are calorically negative, the effect is minimal and drinking large amounts of water can be dangerous.
Some foods not from animal or plant sources include various edible fungi, especially mushrooms. Fungi and ambient bacteria are used in the preparation of fermented and pickled foods like leavened bread, alcoholic drinks, cheese, pickles, kombucha, and yogurt. Another example is blue-green algae such as Spirulina. Inorganic substances such as salt, baking soda and cream of tartar are used to preserve or chemically alter an ingredient.