Many of us were introduced to malt at an early age when a spoonful of cod liver oil and malt was forced down our throats as a childhood remedy. Cod liver oil was a well-known source of vitamins A and D and today is also valued for its omega-3 and omega-6 content.
However cod liver oil has a major drawback- it tastes dreadful. THat’s when a clever pharmacist had the brainwave of mixing it with malt extract to improve its palatability. Cod liver oil and malt has remained a popular nutritional supplement ever since.
Malt extract has a wide number of food application, particularly cereals( breakfast cereals, biscuits and bread), dairy (hot and cold milk beverage, ice cream) chocolate confectionery and of course beer.
Malt is defined as dried barley that has been germinated under controlled conditions, and malt extract is the concentrated water extract of malted barley. Whilst malt is usually made from barley, other grains can also be used. Malted wheat is the principle raw material for Weissbier and malted sorghum has both food and beverage uses. The significance of malt extract as an ingredient is its relatively low sweetness, unique flavour and natural qualities; the purpose of this article is to outline its manufacturing range of applications.
Barley in South Africa is mostly obtained in the Southern Cape region and from the Vaalharts irrigation Scheme around Hartswater in the Northern Cape. After having been cleaned of foreign material, it is transferred to tanks where it is steeped with water and vigorously aerated with air until the moisture content has been increased to around 45%. The steeped barles is then move to a room where temperature and humidity are carefully controlled to ensure that the grain germinates evenly. This is achieved by aerating the grain with humidified air, which also removes the carbon dioxide that has resulted from metabolic activity. Total germination time is usually fewer than five days, during which time the activity of alpha and beta analysis increases. It is these enzymes that are responsible for the degradation of starch in the extraction process.
The germination process is halted by drying (or kilning) when the optimum degree of starch modification and enzyme production has been reached.
Drying proceeds slowly at first to stabilise enzyme activity and then at higher temperatures to develop colour and flavour. The malt is then cooled and stored when the moisture content has been reduced to around 10%.
The malted barley is coarsely ground and fed into a mash tank where it is mixed with water. During a series of time and temperature changes, the starch is converted into maltose and other simple sugars by the action of beta and alpha amylase. Once the hydrolysis of starch has been completed, the mixture is transferred to a mash filter to separate out the insoluble material from the solution (also known as wort).
The wort is concentrated by evaporation under vacuum until the moisture content is around 21% (as measured by refractometer) . Colour and flavour can be controlled at this stage by altering residence time. Finally, the liquid malt extract is filtered, cooled and packaged. A dry malt extract powder may also be produced by processing the wort in a spray-drying tower.
Malt extract is used as a sweetener with flavour and nutritional properties. It has roughly half the sweetness of sugar or golden syrup and there fore can be used in food applications where too much sweetness is undesirable. Being derived from barley, it enhances the flavour of many cereal-based foods including infant formula, biscuits and breads . Breakfast cereals in particular rely on malt extract to mask the bitter notes of high-fibre formulations.
Malt extract has practical applications in the baking industry. In fermented bakery foods, it promotes yeast activity; oven temperatures can be lowered or bake times shortened as crust colour is enhanced. In biscuit and cracker production, the cutting and machining is improved as well as the smoothness and shine of the finished product
In ice cream or milkshake formulations a “double-thic k malt” depends on malt extract as the primary flavour sweetener. Hot or cold milk malted beverages also depend on this ingredient for taste and flavour.
The craft beer industry has grown by leaps and bounds in South Africa in recent years and malt extract is commonly used as a base in brewing processes. In home-brew kits, malt extract eliminates the need for mashing and filtration of the wort and makes the process much easier for the amateur brewer. In commercial breweries, malt extract confers extra gravity and colour to beers such as European ales.
The versatility of malt extract for flavour, nutritional properties, texture and colour in a broad spectrum of applications makes it a highly desirable ingredient in the food industry.