Malt production Print
The basic material for the malt production is spring two-rowed barley and technological, clean water. The production is based on steeping of barley grain and inducing of its germination that leads to the transformation of high-molecular substances with the aid of enzymes into more simple ones and production of new enzymes at the least losses of storage substances, which is called the modification of endosperm of grain.

Process of malt production

silo.jpgSilos for storage of malting barley can be made of steel or iron concrete. They consist of several rectangular six-wall or circular chambers. Chambers can be equipped with pressure or vacuum ventilation.
p2.jpgPre-purified barley is pulled from grain tanks (silos) into winnover and grain sorter. Purification and grading processes take place in the uppermost area of the malt house. During purification process, junk and foreign admixture are removed at first. Consequently, damaged grains and grains of other plants are removed. In the grading process barley is devided into first class barley and outlet unsatisfactory for malting.
p3.jpgThe process of barley steeping takes place in roll steeping tanks with gravity cone of the bottom 45° so that steeped barley could spontaneously outflow. Such conic steeping tanks are made of steel. Conic steeping tanks used by our company are dimensioned for maximum volumetric capacity of 9 tonnes of steeped barley.They are 3,5 meters deep, equipped with device for ventilation by pressure air under the water and for evacuation of carbon dioxide.
p4.jpgLine of sliding pieces is a device used for moving of daily volume of steeped barley into steeping area twice per 24 hours, which represents the first day to the last day of line-distribution onto the kiln. The length of one line is 18 halfdays, which enables exactly nine-day germination. Turner is exactly one halfday long. Fresh, return or mixed air, of which volume can be regulated, is lead with the aid of adjustable flaps under the individual (steeping) area. The air goes through the germinating barley and this affects its temperature – the temperature of the sliding piece.
hvozdenie.jpgKilning is the closing technological process of malt production. It is the process of grain conservation by dehydrating it to the predetermined percentage of moisture. Germination is finished while preserving the highest amount of enzymes and malt is produced with its typical aroma, colour and taste.
odklicovacka.jpgKilning of malt is followed by rootlet separation during which malt is deprived of rootlets, ev. germinating parts at the grain. This secondary product is called "malted flower" and serves as an important proteinaceous fodder plant for animals. The malt is cooled to the storage temperature and stored in the in-depth malt silos.
p7.jpgFreshly kilned malt must be well determinated, cooled and dried. It is stored in malt silos, where it is left for 4 to 6 weeks to mature. At maturation the humidity of malt is spreaded in the whole grain, which leads to chaff plability and physical-chemical changes in endosperm.
lestenie.jpgBefore expedition, it is necessary to deprive malt of dust remains, impurities and chaff. Such purification of malt takes place in polishing machines. At the same time, polishing macines enable mixing of malt of different qualitative parameters in accordance with customer´s requirements. Consequently, malt is transported to dispatch silos from which it can be shipped either as bulk loaded in waggons or bagged.

The process of malting is divided into 3 stages:
  • Steeping
  • Germination
  • Kilning
Steeping of malting barley
After maturation, barley finishes biochemical processes and by storage comes to a relative rest. Grain must have favourable conditions for germination, especially plenty of water, access of oxygen and appropriate temperature. At purchase, barley must contain 12-15% of moisture. For germination to take place, the content of moisture must be increased to 38-42%. The grain gets moisture by alternating steeping in steeping tanks (steeping under the water and interval in the air to avoid oversteeping of the grain during 24 hours)/. It causes swelling of starch and another materials of endosperm.
At present, our company has in use 16 steeping tanks for steeping of malt.

Germination of malting barley on sliding pieces
The purpose of germination of steeped barley is to induce biochemical and physical reactions in grain. The final result is splitting of starch and high-molecular proteins into more simple materials such as maltose, dextrines and aminoacids soluble in water and forming the extract of wort. It is a process of transformation of storage substances of endosperm with the aid of enzymes. Control of germination of grain is called moving pieces. It is the most difficult part of malting process.

Our company has in use 16 sliding pieces and 8 malt-turners which are used for aspersion of barley to reach appropriate humidity and for its aeration. Temperature conditions are maintained by mixing of fresh and return air in chambers under the germination tanks.

The grain at germination needs:
  • vegetative moisture 42-46% (which influences the movement of reserve materials in grain, activates enzymes and supports breathing)
  • appropriate temperature 12-18 °C which influences the growth of grain. The source of heat at germination is breathing of grain. If the temperature is optimal there are no losses of extract of grain
  • oxygen for breathing - germinating barley "expires" carbon dioxide and water steam

The indicator of correct moving of sliding pieces is dew, expired and precipitated water, which keeps constant moisture level at germinating of grain.

Sliding pieces of barley go through different stages - wet pieces, dry pieces, wooly, balanced pieces and old pieces- through the agency of enzymes (phosphatases, cytases, amylases, proteases and lipases). At the end of germination ,the grain content becomes soft, mealy and partly dried. This way green malt is produced which is moved to kilning floors.

Kilning of green malt
The technology of kilning of green malt concludes the technological process of the malt production.

There are three main stages of kilning:
  • conservation of grain by the removal of water - final drying to 3.6 - 4% of moisture. The rootlets of such grain which grew at germination and would negatively influence the taste of grain can be totally removed
  • discontinuance of biochemical processes - to prevent further losses of extract .It is necessary to discontinue germination at a certain time so that the enzymes produced by malting would be preserved as much as possible
  • to create the character of malt - the type of malt is being made at kilning. We produce, in particular, the light Czech type with its characteristic aroma, colour, taste and content of enzymes, which has great influence on quality mostly of light beer.

The product of kilning of green malt is malt - steeped, germinated and kilned grains of barley of which reserve substances have been partly splitted by their own enzymatic activity and which contain enzymes able to transmit another splitting (it is mainly alpha and beta amylase which splits reserve starch substances into maltose which is split by enzyme maltase into glucose, that is fermentable sugar).