Malt glossary

References: D.E. Briggs, J.S. Hough, R. Stevens, T. W. Young, Wikipedia



acid malt: Acid malt may be used to lower the mash pH. Reduction of wort pH leads to a better working mash, intensified fermentation, lighter color, improved flavor stability, and a "well-rounded" beer flavor. Acid malts are made in various ways. For example germinating barley is held under anaerobic conditions for 24 h or more until it becomes acid. This works better if the grain is first macerated, to give the lactic acid bacteria access to the sugars. Alternatively, green malt may be sprayed with a suspension of lactic acid bacterium Lactobacillus delbrückii and then held at about 50 °C for 24-36 h before kilning. Yet another process is to steep kilned malt in water in a well insulated steep tank held at 47 °C.

acrospire: The growth of the acrospire is commonly used as a rough guide to the progress of ‚malting‘. Usually the lengths of the acrospires of a number of grains are noted, as fractions of grain lengths. Thus when the tip of the acrospires is half way up the grain its length is said to be 1/2.; when the tip reaches the grain’s apex its length is 1, and so on. In traditional practice green malt is kilned, and growth terminated, when most acrospires are ¾ -1 the grain’s length.

air-rest: In general, aeration of steeps is insufficient to keep the water fully saturated with oxygen and , in any case, aeration is usually intermittent. A compressor must serve several steeps in turn. Steep aeration is used to maintain grain viability and ensure that subsequently rapid even germination occurs. Air rest are more effective than sparging air into the steep liquor while it is covering the grain, but many malsters use both techniques.

α-amylase: In contrast to β–amylase, α-amylase is absent from mature barley unless it has pre-germinated. During the malting process α-amylase is synthesized de novo. alpha;–amylase is an endo-acting enzyme. It degrades starch to a complex mixture of sugars.

amylopectin: amylopectin differs from amylose in that its chains are extensively branched.

amylose: starch is the major component of the barley grain. The starch can be divided into two fractions: amylose and amylopectin. Pure amylose consists of unbranched chains of molecules.

aqua vitae: Whisky is a shortened form of usquebaugh , which English borrowed from Gaelic (Irish u isce beatha and Scottish uisge beatha ). This compound descends from Old Irish uisce, "water", and bethad, "of life" and meaning literally "water of life". It meant the same thing as the Latin aqua vītae which had been applied to distilled drinks since early 14th century.