Shelf life forcing
I searched to forums and couldn't find any threads on it, so I thought I would start one.
What regimes (temperatures and times) are people using for estimated shelf life determinations? With tunnel pastuerised bottled product, I have in the past used heating to 60 degrees C over 24 hours and then holding for another 24 hours at sixty and then chilling to 2 degrees C over another 24 hours and holding for another 24 hours. Each one of these cycles is supposedly equivalent to 7-10 weeks in trade. I realise that there are many variations on this and I would appreciate your comments.
let me tell you how we handle this issue in Europe according to MEBAK, which all breweries should follow in order to be able to compare the results.
5 bottles are taking and will be treated in temperature cycles between 40 °C ( untreated beer) or 60 °C ( treated beer) and 0°C. As soon as the EBC units for haze increases by 2 EBC the cycle ends and shelf life will be determined. If you are not able to measure the increase in turbidity, you can as well check for an opal cloudiness, which is detectable with the eyes.
And this is how it works: -24 h at 40 or 60 ° C ( see above)
-cooling down to room temp. and then chill to 0°C and keep it at this temp for 24 h
-repeat this till increase of 2 EBC in turbitity (opal)
You will determine a certain number of days. This number you have to multiply with a special beer factor.
determine the factor for you beer: =
Days of shelf life at 20°C
Days of shelf life at 40°C or 60 °C
And so you got the number of days, which the beer will stay without developing non biological haze. Check if the microbiological stability will reach this value as well !
So how do the American brewers handle it?
Greetings from the World Soccer Champion 2006 :-p
Last edited by Øl-sheik; 03-15-2006 at 11:42 AM.