Question

A) Why is the method used in this determination of bitterness only an approximation to the true quantity of iso-alpha acids in a sample of beer?

B) Although this method gives a good correlation between the bitterness of beer and the quantity of iso-alpha acids when fresh hops are used in the brewing process, the correlation is poor when old hops are used. Explain.

Answer 1

A) The International bitterness unit, also known as IBU was established in 1950-60s. And at that time most of the brewers used unrefrigerated bales hoop. The plant part which is ysed in the making of beer is hop. At the time when the method was developed, the hops were used in the brew kettle, which had generally lost in between 40%- 80% of their alpha acid–derived bittering power. Instead of this they had gained some 20% -60% of their bittering potential from oxidation products of the hop resins. As a result, the true bitterness in beer is an approximation of the tr ye quantity of iso-alpha acids in a given sample of beer.

B) . It is important to use fresh hop in making of beer. The use of fresh hops give the good taste to the beer. The age of hops affects the taste of beer. When the hop gets old it looses it's oompah because the grain stales and yeast dies.