Determination of xanthohumol and isoxanthohumol
All beers, beer-based beverages, wort, ethanol extracts, CO2 spent hops and xanthohumol products
Xanthohumol and isoxanthohumol are dissolved with acetonitrile from the sample and following separation, are determined using a Nucleodur C18 column and UV detection.
Determination of the concentration of dissolved carbon dioxide in carbonated beverages in bottles and cans
The total gas pressure in beer is measured after the beer has been forcefully shaken. The carbon dioxide is then bound through the addition of potassium hydroxide. The amount of air in the beer contributes the remaining volume of gas. Once the value for the total pressure has been corrected by subtracting the quantity of air present in the beer, the carbon dioxide can be measured [1].
This method describes how to determine the amount of carbon dioxide dissolved or chemically bound in water.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
This method describes how to determine the free carbon dioxide content of water.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The water sample is titrated with sodium hydroxide against phenolphthalein until a pink color is sustained for 3 min:
CO2 + NaOH → NaHCO3
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Through the addition of solid calcium carbonate to a water sample followed by constant stirring for a period of time, either part of the salt will dissolve or the water will remain unchanged. By examining the sample prior to and after the addition of calcium carbonate, one can quantitatively determine whether it is lime-aggressive or not.
Determination of the concentration of dissolved carbon dioxide in carbonated beverages through titrimetry (dimensional analysis)
This method is suitable for determining the dissolved carbon dioxide in carbonated beverages for concentrations ranging from 0 to 8.4 g/l.
Through the addition of a sodium hydroxide solution, the carbon dioxide in beer becomes bound as sodium hydrogen carbonate or sodium carbonate. Sulfuric acid is added to an aliquot of the beer treated with sodium hydroxide. This causes the carbon dioxide to be released again, after which a stream of air conducts the carbon dioxide into a barium hydroxide solution. Through titration of the excess barium hydroxide, the carbon dioxide content of the beer can be determined [1].