Malting barley methods used to measure quality

At the Grain Research Laboratory, unless otherwise specified, analytical results for barley and malt are reported on a dry weight basis. The ASBC methods cited are those of the American Society of Brewing Chemists, 14th Edition.

List of western Canadian malting barley methods and tests

α-Amylase activity
α-Amylase activity is determined according to ASBC method MALT 7B by segmented flow analysis, using ASBC dextrinized starch as the substrate, and calibrated with standards that have been determined by method ASBC Malt 7A.
Assortment
All samples are passed through a Carter Dockage Tester equipped with a No. 6 riddle to remove foreign material and two slotted sieves to sort the barley. Plump barley is the material retained on a 6/64” (2.38 mm) x 3/4” slotted sieve.
Intermediate Grade is barley that passes through the 6/64” x 3/4” sieve but is retained on a 5/64” (1.98 mm) x 3/4” slotted sieve.
β-Glucan content
β-Glucan content is determined in malt extract by segmented flow analysis using Calcofluor staining of soluble, high molecular weight ß-glucan (ASBC Wort-18B).
Diastatic power
Diastatic power is determined by segemented flow analysis, using an automated neocuproin assay for reducing sugars, which is calibrated using malt standards analysed using the official ferricyanide reducing sugar method, (ASBC Malt 6A).
Fine-grind and coarse-grind extracts
Extracts are prepared using an Industrial Equipment Corporation (IEC) mash bath and the Congress mashing procedure from 45°C to 70°C. Specific gravities are determined at 20°C with an Anton Paar DMA 5000M digital density meter (ASBC Malt-4).
Free Amino Nitrogen (FAN)
Free amino nitrogen is determined on the fine extract according to the official ASBC method Wort-12 by segmented flow analysis.
Germination energy
Germination energy is determined by placing 100 kernels of barley on two layers of Whatman #1 filter paper, in a 9.0 cm diameter petri dish, and adding 4.0 ml of purified water. Samples are controlled at 20 degrees Celcius and 90% relative humidity in a germination chamber. Germinated kernels are removed after 24 and 48 hours and a final count is made at 72 hours (ASBC Barley 3C).
Kolbach index (Ratio S/T)
Kolbach index is calculated from the formula, (% Soluble protein/% Malt protein) x 100.
Micromalting
Malts are prepared using an Automated Phoenix Micromalting System designed to handle twenty-four 500 g samples of barley per batch.
Malt mills
Fine-grind malt is prepared with a Buhler-Miag disc mill set to fine-grind. Coarse-grind malt is prepared with the same mill set to coarse-grind. The settings for fine- and coarse-grinds are calibrated quarterly, based on the screening of a ground ASBC standard check malt (ASBC Malt-4).
Moisture content of barley
Moisture content of barley is predicted using NIR equipment that has been calibrated by the standard ASBC method (ASBC Barley 5C).
Moisture content of malt
Moisture content of malt is determined on a ground sample by oven drying at 104°C for 3 hours (ASBC Malt-3).
Protein content (N x 6.25)
Protein content is predicted on dockage free barley using NIR equipment that has been calibrated by Combustion Nitrogen Analysis (CNA). CNA is determined on a LECO Model FP-428 CNA analyzer calibrated by EDTA. Samples are ground on a UDY Cyclone Sample Mill fitted with a 1.0-mm screen. A 200-mg sample is analyzed as received (it is not dried prior to analysis). A moisture analysis is also performed and results are reported on a dry matter basis (ASBC Barley 7C).
Rapid Viscometric Analysis
The degree of pre-germination in barley was determined as described by Izydorczyk (2005); see Using RVA to measure pre-germination in barley and predict germination energy after storage. Samples were analyzed using the RVA-4 (Newport Scientific) and the Stirring Number Program. Final viscosity values were presented in Rapid Visco Units (RVU).
Viscosity
Viscosity is measured on fine grind Congress wort using an Anton Paar Lovis 2000 automated rolling ball viscometer (ASBC Wort-13B).
Water Sensitivity
Water sensitivity is determined exactly as described for germination energy, except that 8.0 ml of purified water is added to each petri dish (ASBC 3C, IOB and EBC procedure). The water sensitivity value is the numerical difference between the 4ml and 8ml tests.
Weight per Thousand Kernels
A 500 gram sample of dockage-free barley is divided several times in a mechanical divider to obtain one representative 40g sub-sample. All foreign material and broken kernels are removed from one 40 gram portion and the net weight determined. The number of kernels is then counted with a mechanical counter and thousand kernel weight is calculated (as is basis) (Institute of Brewing’s Recommended Methods of Analysis, Barley 1.3 (1997)).
Wort-Soluble Protein
Wort-soluble protein is determined spectrophotometrically using ASBC method Wort-17.
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