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High molecular weight dextrins and starch present in the wort extracted from brewery spent grain are precipitated through the addition of ethanol, centrifuged and dissolved in phosphate buffer, followed by the addition of an iodine solution. Depending on the molecular weight and degree of branching, a red to blue color forms, the intensity of which is measured spectrophotometrically at 578 nm.

Malt is ground between two horizontally positioned, grooved discs. The lower disc is driven by an electric motor and rotates at approx. 1500 rpm; the upper disc is fixed and therefore does not move. During the milling process, the malt migrates from the center of the discs to the outer edge, where the grist falls through an outlet spout into a grist beaker.

The gap between the discs can be adjusted by turning a socket head screw on a calibrated ring bearing scale markings. The scale on the calibrated ring ranges from 0 to 20, with each scale division corresponding to a gap between the discs of 0.10 mm. Each scale division is subdivided into five smaller divisions; each of the smaller marks is equivalent to 0.02 mm. Two gap adjusting rings ensure reproducible mill settings.

High-molecular weight dextrins and starch present in the wort extracted from brewery spent grains are precipitated through the addition of ethanol, centrifuged and dissolved in phosphate buffer, followed by the addition of an iodine solution. Depending upon the molecular weight and degree of branching, a red to blue color forms, the intensity of which is measured spectrophotometrically at 578 nm.

A representative sample is required for monitoring brewhouse operations by means of a spent grain analysis. To achieve this, samples of an identical size are collected from the spent grain conveyor at the same time intervals.

The moisture content is determined by means of the loss in mass during a standardized drying process. For this purpose, the spent grain is dried at a defined temperature over a set time in an electrically heated air drying oven. The moisture content is determined by the difference in weight before and after drying.

If the barley possesses a moisture content of more than 17 % w/w, the whole kernels shold be dried prior to grinding them and determining the moisture content in the (coarsely ground) spent grain. The moisture content of the finely ground spent grain is subsequently determined and the total moisture content calculated from both values.

Wet spent grain is pressed using a manual press.