Base (chemistry) Base (chemistry) In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH ions. Examples of bases are the hydroxides of the alkali metals and the alkaline earth metals (NaOH, Ca(OH), etc., see alkali hydroxide and alkaline earth hydroxide). These particular substances produce hydroxide ions (OH) in aqueous solutions, and are
Wine chemistry by "Brettanomyces" that cause wine faults include 4-ethylguaiacol and isovaleric acid. Coumaric acid is sometimes added to microbiological media, enabling the positive identification of "Brettanomyces" by smell. Geraniol is a by-product of the metabolism of sorbate. Fusel alcohols are a mixture of several alcohols (chiefly amyl alcohol) produced as a by-product of alcoholic fermentation. Wine chemistry Wine is a complex mixture of chemical compounds in a hydro-alcoholic solution with a pH around 4. Gum arabic has been used in the past as fining agent. List of additives permitted for use in the production of wine under EU law: A wine