Ok,

Degrees Brix is a measurement of the percent by weight of sucrose in solution at 60 degrees F. The higher the degrees Brix, the greater the content of sugars in the sample.

For example;

1993 Handley Cellars Chardonnay = 23 Degrees Brix (which means there is 23% sugar in solution).

Natural Orange Juice = approx. 11 or 12 Degrees Brix

The term "Degrees Brix" is 150 years old, named after Dr Antoine Brix and is commonly used by winemakers. There are several other scales of measurement used in lieu of degrees Brix. For example, the Baume scale is also used in Europe - it was named in 1768 after it's creator Antoine Baume. An online conversion table between Brix and Baume is

available here.
(Ok, enough of the history wankfest!!)

Liquid Malt Extract is typically 80 Degrees Brix. There are 4 brewers degrees per one Degree Brix. This means that the SG of 1Kg of 80 Degrees Brix LME in 1 Litre of water is 320 brewers degrees or 1.320.

Dry Malt Extract has a higher sugar content again - it measures approximately 90 degrees Brix = 1.360 or 360 brewers degrees.

Sucrose yields an SG of 1.386, ie, 96.5 Degrees Brix.

Armed with this info, we can easily calculate the Original Gravity and amounts of malt required in the wort of a given volume.

In this case, let's see how much malt I need to make 23 Litres of beer from hell with an Original Gravity of 1.090... :blink:

If I use LME, I know the weight of the malt = 320 brewers degrees (80 Degrees Brix)

I know the final volume of the wort to be fermented (this volume is the solution plus malt added, NOT the volume that you add malt too) = 23 Litres

The amount of malt required is therefore = OG/(SG of malt/Vol of Wort)

IE = (90/(320/23))

= (90/13.913)

= 6.46877 Kg

Or, if I used Dry Malt Extract at 90 Degrees Brix;

= (90/(360/23))

= (90/15.652)

= 5.7500 Kg

So, I need 6.47Kg of LME or 5.75Kg of DME to produce a 23L wort with a starting gravity of 1.090 at 60 Degrees F (16C).

With a bit of manipulation, you can use the above formula to tell you what the Original Gravity of the wort will be, based on a given volume and amount of malt added.

OG or SG of wort = (Weight of Extract x SG of Extract) / Volume of Wort.

So 6.47Kg of LME in 23 Litres results in:

OG = (6.47 x 320) / 23 = 90 Brewers Degrees (1.090)

Cheers,

TL