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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.

This test provides information regarding any odors transferred by filter aids to wort and beer. A minimum of three samples should be collected from each lot of the product delivered.

This test provides information regarding any flavor transferred by a filter aid to wort and beer. The filter aid is added to water at 20 °C and tasted.

Alkaline cleaning agents and disinfectants containing chlorine can be determined by their alkalinity concentration. The chlorine present destroys most indicators by oxidation. Before adding the indicator, the chlorine must be eliminated by adding sodium thiosulphate to the sample.

Determination of the quicklime (CaO) or sodium hydroxide (NaOH) content of the detergent solution with an acid solution (HCl or H₂SO₄) with corresponding equivalent concentration (normality) up to the color change of phenolphthalein (pH 8.2).

Quicklime

Sodium hydroxide

If the alkaline solution is likely to be strongly influenced by carbonic acid or if the cleaning solutions are used over a longer period of time ('batch cleaning'), the degree of carbonation must be taken into account to determine the exact concentration or pH value, as the resulting soda has a greatly reduced cleaning effect, but simulates an excessively high concentration of the active cleaning agent.

Determine the sodium hydroxide (NaOH) content of the detergent solution with an acid solution (HCl or H₂SO₄) with corresponding normality up to the color change of phenolphthalein (pH 8.2).

   NaOH + HCl           →         NaCl      +   H₂O             colorless against phenolphthalein

2 NaOH + H₂SO₄      →         Na₂SO₄ + 2 H₂O

Determination of the soda ash (Na₂CO₃) content of the detergent solution with an acid solution (HCl or H₂SO₄) with corresponding normality up to the color change from methyl orange (pH 4.3).

   Na₂CO₃  + HCl        →       NaHCO₃  + NaCl

   NaHCO₃  + HCl        →      NaCl      + H₂O + CO₂    yellowish brown against methyl orange

2 Na₂CO₃   + H₂SO₄   →   2 NaHCO₃ + Na₂SO₄

2 NaHCO₃  + H₂SO₄    →  2 Na₂SO₄ + H₂O + 2 CO₂