SUGAR Points..the way?

On the last few brews that I've done I have been experimenting with 'Sugar Points', Phil a member on www.thehomebrewforum.co.uk got me interested in doing this, it is in basic terms a method of ensuring that you collect the right amount of sugar from your mash to ensure that you hit the gravity that you want.

It calls for a bit of math, so as I sit here typing this with Hoegaarden in hand I'll try my best to explain how I understand it.

The start point that you need is to know three things

a) What your desired OG is
b) What your desired volume into fermenters is
c) How much you loose after the boil to your boiler, hops etc

To aid explanation we will assume that our three figures are:

a) 1.050
b) 25 litres
c) 8 litres


The amount of sugar points needed for 33L at 1.050 (33L is 25L + losses of 8L) is 33 x 50 = 1650

So what you do is calculate your grist as you normally would, based on your own known brewhouse efficiency but when you sparge measure what you have collected both in volume and specific gravity and stop sparging when you have collected your required sugar points (1650 for this example) (A refractometer is very useful for this).

You do this by multiplying what you have collected by the gravity of what you have collected. Your own efficiencies will dictate at what volume you reach your required Sugar Points, for the sake of this example lets say we collected 25L of 1.066 wort ... 25 x 66 = 1650.

This 25L is then diluted down to your pre-boil volume (you will have to work that out based on your equipment), boil happily away down to your post boil volume knowing that it will be at the OG you want.

It sounds complicated but it easy really.

I'll be lowering my efficiency to 65% from 85% next time to try to improve the quality of extract.