This method describes how to determine the gushing potential of a sample to be analyzed.
Malted and unmalted grain intended for use in beer brewing or elsewhere in the food industry
A cold water extract of a malt or adjunct (coarse grist) is concentrated through boiling; subsequently, standardized bottled water is added to the extract. The extract is filled in bottles. After the bottles have been shaken according to a defined procedure, they are opened and the weight of liquid fobbing out of the bottles as foam (gushing) is determined and taken as a measure of the gushing potential for the malt or adjunct in question.
This method describes how to determine the tendency of a sample to exhibit gushing.
Malted and unmalted grain intended for use in beer brewing or elsewhere in the food industry
A sample is collected of the cereal to be tested and a hot water extraction is carried out. After cold break separation, the sample is carbonated and bottled. After shaking and then opening the bottle, the volume of liquid that fobs over and out of the bottle is measured. This value is used to determine the gushing potential for the malt or adjunct.
wort, beer
High molecular weight dextrins and starch present in wort or beer are precipitated through the addition of ethanol, centrifuged, dissolved in phosphate buffer, followed by the addition of an iodine solution. Depending on the molecular weight and degree of branching of the erythrodextrins and starch, a red to blue color forms, the intensity of which is measured photometrically.
Determination of the amino acid content in wort and beer
This modified Kroemer method is suitable for wort and beer [1].
Amino acids are polar in their natural state and only rarely possess chromophores, which absorb UV light.
Fluorescing derivatives are formed by means of derivatization in the precolumn with ortho-phthaldialdehyde (OPA). These are separated using HPLC and detected with a fluorescence detector.
Amino acids are essential for yeast metabolism during fermentation. A deficiency can lead to considerable disruptions during primary fermentation and in the formation of fermentation by-products as well as to delays in the maturation process.
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].
Determination of iso α-acids and α-acids 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.
These bitter substances are extracted from the acidified sample using iso-octane. Certain disruptive substances are eliminated through washing the extract with acidified methanol. The concentration iso-α-acids as well as α-acids is determined by measuring the absorbance in alkaline methanol at 255 nm and 360 nm.