With the current boom in craft brewing, we have seen more and more beer samples arriving at Vinlab. So we have been busy researching beer analysis techniques in order to provide the best possible service to our beer clients. Beer is different to wine, and analyzing the same parameters is not always appropriate. Below is the beer analysis we now offer.
CHEMICAL AND PHYSIOCHEMICAL PARAMETERS:
• Real Extract: The amount of dissolved solids in a beer (i.e. everything except the alcohol and CO2)
• Apparent Extract: The attenuation of beer containing alcohol, excluding the CO2
• Original Extract: The amount of dissolved solids in wort (1% Plato= 1% w/w)
• Real Degree of Attenuation: The degree to which the dissolved solids in a wort have been fermented. Brewers do not measure residual sugars as winemakers do, but rather the degree of attenuation, i.e. the degree to which the fermentation yeast has consumed its wort sugars.
• Free and total SO2
• Dissolved CO2
• Air Index: A measure of all the gasses excluding CO2
• Lactic acid
• Colour 430nm
• International Bitterness Units: A stylistic measurement of bitterness as contributed by the hops.
• Diacetyl: A buttery/butterscotch flavour compound produced by yeast and bacteria during production. The sensory threshold in beer is 0.1mg/L. Higher levels are mostly considered undesirable.
• Force tests: Measurements of the various colloidal stabilities of beer to predict shelf-life.
The methods include tests for yeast, aerobic bacteria and anaerobic bacteria and should be relevant for the presence of any of the following beer spoilage microorganisms:
• Fermentation yeast (usually Saccharomyces)
• ‘Wild’ yeast
• Other aerobic yeast
• Acetic acid bacteria
Note that identifying microorganisms by genus is not always possible using these traditional methods. But using culture together with additional techniques we will try to identify as far as possible any microbe growth.
A full beer microbiological analysis includes the following:
• Yeast culture
• Aerobic bacteria culture
• Anaerobic bacteria culture
• Any additional techniques required in further identifying the microorganisms.