Testing solutions for brewing.

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Testing solutions for brewing.

In breweries the main testing areas are input water quality, discharge (waste) water, mashing and wort monitoring, beer quality and sanitation.

Some tests of input water quality can be carried out at the brewery. These include hardness, chlorine levels including combined chlorine, overall salt level as conductivity and pH. Bacteria test kits are available eg the Coliscan and Total count Easygel kits for onsite regular testing of bacteria levels in washing and cooling water.

Water 'quality' is usually assessed by a suite of factors that include corrosion potential, oxidizing potential and dissolved organics. More complete testing for input water is best carried by a lab that will test water quality factors relevant to a particular industry. A lab will usually provide a more complete profile of the individual salts and main metals. Testing should include a report that highlights significant issues and can be used to choose water treatment options.

To measure pH in discharge water requires wide range test strips particularly extending into the more acidic low pH range. pH-Fix test strips are ideal for this with a range from 0 - 14 pH. Use the same test strips to check if the waste has been neutralized to the acceptable range. Don't risk pH meters in waste water because probes are more likely to be harmed by other particularly organic contaminants. Besides there is a risk on cross contamination if someone uses the same meter in the beer!

Mash pH can be quickly tested with pH strips with the appropriate range. Duotest pH paper for pH 3.5 - 6.8 is ideal. pH meters can be used in wort but please only use them in a sample that can be discarded. The other important point is that it's the type of pH probe that matters. Probes are designed for a variety of purposes and in particular probes to be used in foods or beverages are designed to resist clogging. Budget priced pH testers are better for primarily water-based solutions with low contaminants and organic materials.

Many brewers use hand held refractometers to measures sugar level in wort but now there is not much price difference between hand-helds and digital refractometers. Get a digital refractometer with ATC to make life easier.

Around the brewery there is always a need for spot checking temperatures in a number of places for example in the wort, coolrooms and fermenters. Simple thermometers like the Hanna Instruments Checktemp range provide quick checks. They can be checked against ice water or boiling water. More advanced thermistor type thermometers can allow internal and external calibration checks. Thermocouple thermometers offer the advantage of a wide range of replaceable probes to suit different situations.

Beer haze is a useful measure for quality control. Dedicated beer haze meter are made to conform to various standards for testing beer haze. These include European Brewery Convention EBC and American Society of Brewing Chemists ASBC. An example is the Hanna Instruments HI84749X beer haze photometer series. Other haze meters report beer haze using the FNU turbidity standard.

Testing for sanitation can include testing the strength of sanitizing solutions and testing for residual levels of sanitizer.

Example: There is a liquid commercial sanitizing product available to the food industry that contains peracetic acid and hydrogen peroxide. Concentrations are 50 gm/kg peracetic acid and 250 gm/kg hydrogen peroxide. The product comes in concentrated form so has to be diluted before use. Suggested dilutions are from 1:200 to 1:500. At the lesser dilution (stronger final solution) the final concentration is: peracetic acid 250 mg/L and hydrogen peroxide 1250 mg/L. At the greater dilution (weaker final solution) peracetic acid 100 mg/L and hydrogen peroxide 500 mg/L. If the weaker solution is being used for disinfecting then 160 ppm peracetic acid test strips can be used to check the solutions strength. If using the stronger solution then use 1000 ppm peracetic acid test strips. To test for adequate hydrogen peroxide use 1000 ppm peroxide test strips.

In some applications where hydrogen peroxide is used as a disinfectant, regulations require a maximum residual level. To test this use 100 or 25 ppm peroxide test strips. These test very low or trace levels.

 

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