Easily confused with :
Four-row Barley, a cultivated variety of
Six-row Barley (Hordeum vulgare) which has six vertical columns of fertile florets/fruits around the stem.
There is also a
Six-row Barley (Hordeum vulgare) which also exist in the wild, escaped from arable fields. Some books list a 'four-row barley' but this is apparently the common name for a variety of six-row barley where the 3 fertile florets per triplet do not form 6-rows, but two of those sets are superimposed into one of the other vertical rows, creating just 4 vertical rows, but with the same number of fertile florets as 6-row barley.
Barley belongs to the Grass Family (Poaceae).
Sprouting Barley seeds contain Hordenine (in their roots as the main alkaloid). Hordenine is a Phenylethylamine not dissimilar to Dopamine. Hordenine exhibits anti-biotic and anti-bacterial properties and in mammals it stimulates the release of the hormone and neurotransmitter Noradrenaline (otherwise known as norepinephrine) which increases the heart-rate. As an anti-biotic Hordenine has an inhibitory action on at least 18 strains of penicillin-resistant Staphylococcus bacteria.
Barley is an essential crop used in the brewing of beer. The barley grains are first dried to below 14% moisture then left for up to 6 weeks to bring them out of dormancy. They are then soaked in water 2 or 3 times over several days to make them germinate and sprout. When the grain reaches 46% moisture content the grain is ready to be air-dried over five days by constantly turning them over. The grain is then called 'green malt' which is kiln dried at about 55°C with hot air and smoke to the desired colour. This process enzymatically converts the polysaccharides to lower sugars. There are Crystal Malts which are pale, amber and chocolate malts and finally black malts, all depending upon the amount of roasting they receive during this kiln-drying stage.
The process is called 'malting', which develops the enzymes necessary to change the grains starches (polysaccharides) into several sugars such as
Glucose (a monosaccharide),
Maltose (a disaccharide),
Maltotriose (a trisaccharide with three glucose units) and
Maltodextrins (higher sugar polymers with between three and seventeen glucose units - which therefore also includes Maltotriose in the definition).
Sucrose (a disaccharide) and
Fructose (a monosaccharide) are already present in small amounts in the grain and remain in the Malt produced. If 55°C is exceeded then the enzymes that catalyse the conversion will be damaged.
Speciallity darker malts are created by a further (hotter and therefore non-enzymatic heat treatment) to create caramel and crystal malts. Malt extracts are either liquid malts with similar consistency to treacle or dry malts similar to brown sugar and are prepared at or below 55°C to preserve enzymatic conversion of polysaccharides to sugars. The process of malt extract production differs in several respects to that of malt production - the enzymatic conversion of polysaccharides to sugars is termed 'mashing' and is usually carried out in a brewery rather than in a maltings. It results in differing proportions of sugars, the malt extract process (which is simpler than malting) usually resulting in 7% less of the polysaccharides being converted into lower molecular weight sugars.
Barley is the most commonly used grain for producing malt, but other grains such as
Rice can and have been used. Malts are further specified by whether 2-row or 6-row barley was used in their making.
|BREWING BEER WITH MALT
Glucose and the disaccharides Maltose are metabolised by yeast during the beer brewing process to produce Ethyl Alcohol and
Carbon Dioxide. Sucrose (which consists of two monosaccharides D-(+)-Glucose (aka Dextrose) and D-(-)-Fructose) present can be converted into alcohol by yeast, but it will take longer. Any sucrose can be brewed more effectively by 'inverting' it first - which hydrolyses it into its two constituent monosaccharides (either by boiling it at 114°C with a weak acid such as
Citric Acid or by using the enzyme 'Invertase'). Sucrose can be used for priming the yeast, but will inevitably take longer.
Maltodextrin plays no part in the beer brewing process, it is not converted to alcohol, but it does improve the mouthfeel and increases the head-retention time of poured beers.