# CALCULATIONS

Calculating E.B.U. EBU (European Bitterness Units) determine the bitterness of a beer. To calculate the weight of hops required to produce a beer with a certain EBU, the following formula is used:

Weight (g)  =  EBU x Volume (litres)
Alpha Acid x 2

For example, to brew a beer of 23 litres with an EBU of 30 using hops with an alpha acid of 7%:

30 x 23   =   460   =   32.86      therefore 33g of hops are used
7 x 2            14

Alpha acids vary from hops to hops. If you obtain the same type of hops and the alpha acid changes, the following formula is used to re-calculate the new weight of hops required.

New weight (g)  =    original weight x alpha acid of original hop
new alpha acid of hops

e.g., 30g of hops with an alpha acid of 6.5% were previously used. The new alpha acid is now 7%:

30 x 6.5   =  27.86         therefore 28g of hops are now required
7

Calculating A.B .V.

To calculate the ABV (Alcohol By Volume) of a beer, the following formula is used:

ABV = original gravity – final gravity

7.46

For example, if the original gravity is 1040 and the final gravity is 1010:

1040 – 1010  =   30   =   4.02     therefore the ABV is 4.0%
7.46          7.46

Working with Tempertures When using the full mash process, the ideal strike heat temperature is from 73˚C to 76˚C. Once the water has mixed in with all the malt grist, the mash temperature should be approximately 66˚C. However a mash temperature between 64˚C and 69˚C will still produce good results.

When sparging, a temperature of 78˚C is ideal for rinsing out sugars from the malts.

A rolling boil of 90 minutes is necessary to allow proteins to be removed thus allowing clearer beer.

Once the boil is complete, the wort is cooled down to around 20˚C before pitching in the yeast.

..

Advertisements
Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.