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The hot break material (trub) and any hop particles which may be present in the wort, must first be removed. After the wort has been cooled to 2 °C, it is filtered through a glass fiber filter. The residue remaining on the filter is dried and then weighed.

Cold break material or cold trub refers to all material that settles out in the process of chilling wort after separation of the hot trub or hot break material. Cold trub can be filtered out of the wort and primarily consists of proteins (48–57 %), tannins (11–26 %) and carbohydrates (20–36 %). The amount of cold break material in wort depends on the quality and composition of the raw materials, brewhouse equipment and wort handling. In academic and professional circles, opinions regarding the significance of cold break material for downstream processes and for the quality of the finished beer are strongly divided [1, 2, 5]. Under certain circumstances, the quantity of cold break material in wort may exceed 250 mg/l, especially where accelerated fermentation is practiced. Ultimately, this can detract from the flavor of the finished beer [3]. Breweries, where removal of the cold break material has been practiced successfully, determine the quantity of cold break in their pitching wort at regular intervals, in order to evaluate the efficacy of their separation equipment.

After milling, hops and hop powder products are extracted using a diethyl ether/methanol mixture and a hydrochloric acid solution. The α-acids and β-acids dissolved in the ether phase are separated using reversed phase high-pressure liquid chromatography (RP-HPLC) and measured spectrophotometrically at a wavelength of 314 nm.

Hop extracts are dissolved in methanol. The α-acids and β-acids dissolved in the methanol are separated using reversed phase high pressure liquid chromatography (RP-HPLC) and measured spectrophotometrically at a wavelength of 314 nm.

Evaluation of the appearance of hop cones is performed through visual and manual inspection.

The time from the beginning to the end of filtration is determined when producing a laboratory mash. 

In order to test the influence and effects of filter aids in a routine production situation, it is recommended that a filtration trial be conducted under standard operating conditions.

The odor and flavor of the filtered beer is also tested as part of this trial.

The test should be conducted against a control sample that has not been in contact with the material to be tested.

The electrical conductivity of a water sample is regarded as a sum parameter of all of the ions dissolved in the water sample. The electrical conductivity is determined by the ion concentration and the types of ions as well as the temperature and the viscosity of the solution. Due to dissociation of the water molecules themselves, water containing no dissolved extraneous ions possesses an extremely low electrical conductivity of ≤1 µS/cm^-1. Drinking water often exhibits conductivity between 100 and 1000 µS/cm^-1 (limit threshold according to the Trinkwasserverordnung – TrinkwV (the regulations governing drinking water in Germany): 2500 µS/cm^-1 at 25 °C). By comparison, rainwater exhibits a value for electrical conductivity between 30 and 60 µS/cm^-1, while that of sea water is commonly 42,000 µS/cm^-1.