Malt intended for use in beer brewing or elsewhere in the food industry
The substrate for the limit dextrins is prepared by adding excess β-amylase to a standard solution of starch. An extract of malt is added, and the α-amylase present in the malt brings about the degradation of the limit dextrins. With the addition of an iodine solution, the time required for the standard color of the starch-iodine complex to be reached is known as a “dextrinizing unit” [1].
Suitable for beer
Aside from the total glucose content, there are other carbohydrates which can be added together to yield the sum of the bread units in a (highly attenuated) beer.
Malt intended for use in beer brewing or elsewhere in the food industry
The aliquot of an extract of malt is added to a buffered starch solution and allowed to stand for exactly 30 min at 20 °C. Then, the maltose – formed primarily from the starch through the action of the β-amylase – is measured using iodine and is determined according to the following chemical reaction:
Determination of bittering units in beer, beer-based beverages and wort.
This method is not suitable for beer, beer-based beverages or wort, which contain saccharin, p-hydroxybenzoic acid ester, salicylic acid or sorbic acid.
The bitter substances, primarily iso α-acids, are extracted using iso-octane from the acidified sample, and their concentration in the extract is determined spectrophotometrically [1].