Spectrophotometric determination of the iodine value of brewery spent grain
Brewery spent grain, wet spent grain, dry spent grain
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.
Determination of the brewhouse yield/hot wort yield in order to evaluate brewhouse operations
Cast-out wort after the completion of wort boiling prior to hot break separation
The brewhouse yield/hot wort yield represents the extract present in one batch of wort relative to the raw materials used to produce the wort. The malt, any supplements added to the mash, and brewhouse operations determine brewhouse yield.
An assessment of brewhouse operations and processes is possible through comparison with the laboratory yield, prepared using the same malt and supplements in the mash. However, the brewhouse yield does not allow a distinction to be made regarding where extract losses occur in the brewhouse, i.e., whether they stem from the mashing or lautering process and in which proportions. For this, a spent grain analysis is required.
Determination of the fermentation cellar yield in order to monitor brewhouse operations
Wort from the midpoint of chilling/pitching wort
The fermentation cellar yield is calculated using the value determined for the amount of extract contained in a batch of wort relative to the amount of extract present in the raw materials used to produce the wort.
This method describes how to determine the quantity of pests present in a lot of barley using visual and manual inspection processes.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
Visual and, if applicable, an aural assessment of the barley.
This method describes how to mill grain or malt to produce fine or coarse grist.
Malt intended for use in beer brewing or elsewhere in the food industry
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.
Collection of a representative sample of spent grain
Spent grain
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.