OLIGOSACCHARIDES - Sugars of more than three molecules, less complex than dextrins.
ORIGINAL GRAVITY - It is a measure of the total amount of dissolved solids present in the beer wort before fermentation. This is expressed in degrees Plato or specific gravity, which is equivalent to the total percentage of fermentable and unfermentable sugars. Abbr.: O.G.
OXIDATION - Any chemical reaction in which oxygen combines with another substance, often times causing off-flavors; wet cardboard, papery, winery, sherry.