Accepted malting barley varieties have to modify evenly and produce finished malt whose properties lie within the brewers specifications. The malt quality of a given barley variety is determined by its genetic background and the physical conditions during growth, harvest and storage. Malting quality has to be tested in micro-, pilot- and industrial malting trials, and brewing trials also in pilot and production scale. The quality specifications on barley for production of malt prevalent in Europe are listed below:
¢ Germination % min. 97% after 3 days ¢ Germination index min. 6. 0 ¢ Water content 12. 0 %, max. 13. 0 % ¢ Protein content > 9,0 % and < 11,5 % ¢ Grading min. 90 % > 2. 5 mm. ¢ ? -glucan content max. 4 % ¢ Micro-organisms below a set level. ¢ Pesticide residues according to national law ¢ Ochratoxin according to national law ¢ Aflatoxin according to national law ¢ Variety purity min. 99 % Before a new barley variety can be accepted for the production of mal, it needs to be generally accepted by farmers for cultivation.
The harvested crop must meet the barley specifications, give a malt quality within the actual specifications, and be trouble free in the brew house and fermentation-processes and give a beer quality with good taste and taste stability. Varieties are tested in micro-, pilot- and production scale malting and go through production brewing trials. The preliminary acceptance is dependent on all the test results. Full acceptance is reached when 1000 ton malt has been used in brewing with a high quality commercial brewing performance.
Some barley varieties, which are the basis for malt used in Carlsberg products, are Aspen, Alexis, Alfa, Alliot, Amulet, Angora, Ariel, Arapiles, Akcent etc. In USA, the specifications on the barley for malting are issued by American Malting Barley Association (AMBA). The specifications are presented in the table below : Barley Factors Two-Row Barley Six-Row Baley Plump Kernel (on 6/64) >90% >80% Thin Kernel (below 5/64) <3% <3% Germination (4 ml 72 hrs GE) >98% >98% Protein 11. 0-13. 0% 11. 5-13.
5% Skinned & Broken Kernels <5% <5% Malt Factors Total Protein 10. 8-12. 8% 11. 3-13. 3% On 7/64 screen >70% >60% Measures of Malt Modification Beta-Glucan (ppm) <100 <120 F/C Difference <1. 2 <1. 2 Soluble/Total Protein 40-47% 42-47% Turbidity (NTU) <10 <10 Viscosity (absolute cp) <1. 5% <1. 5% Congress Wort Soluble Protein 4. 4-5. 6% 5. 2-5. 7% Extract (FG db) >81% >79. 0% Color (% ASBC) 1. 6-2. 2 1. 8-22 FAN >180 >190 Malt Enzymes Diastatic Power (% ASBC) >120 >140 Alpha Amylase (DU) >45 >45.
Table 4: Specifications for malt barley as issued by The American Malting Barley Association (AMBA) (ambainc. org) Besides, following general specifications should also be met by the barley: (a) It should mature rapidly, break dormancy quickly without pregermination and germinate uniformly. (b) Hull should be thin, shiny and should adhere well with the plump during harvesting, cleaning and malting. (c) It should exhibit well balanced malting in conventional malting schedule with four day germination and (d) Malted barley must provide desired beer flavor.