D_BLOCK
Member
I've been reading up on all-grain brewing and the amount of sugars you can expect to get out of your malts. I don't understand how to convert the percent yield (weight of extractable sugar / weight of malt) to specific gravity or points per pound per gallon. I have a table that does this, but I am trying to understand an equation to do this.
I tried to do this with sucrose, which has a 100% yield. I came up with: (3.8 kg water + 1/2.205 kg sugar) / 3.8 L water = 1.119 kg/L. Thus, one pound of sugar dissolved in one gallon of water should yield a solution with a specific gravity of 1.119, or 119 GU points per pound per gallon.
However, this is off by a factor of ~2.6, as we all know the correct answer is 46 points.
I get the same thing when I calculate using metric units (points per kg per liter): (1+1)/1 = 2. So 1000 points. It should be about 386 points. Again I am off by a factor of ~2.6.
There must be something I am not understanding or something wrong with my methodology. Does anyone know how the values in those % yield to GU point conversion tables are derived?
I guess this isn't necessary to understand for the brewing process, but i figured someone on here may be able to come up with an answer.
THANKS
I tried to do this with sucrose, which has a 100% yield. I came up with: (3.8 kg water + 1/2.205 kg sugar) / 3.8 L water = 1.119 kg/L. Thus, one pound of sugar dissolved in one gallon of water should yield a solution with a specific gravity of 1.119, or 119 GU points per pound per gallon.
However, this is off by a factor of ~2.6, as we all know the correct answer is 46 points.
I get the same thing when I calculate using metric units (points per kg per liter): (1+1)/1 = 2. So 1000 points. It should be about 386 points. Again I am off by a factor of ~2.6.
There must be something I am not understanding or something wrong with my methodology. Does anyone know how the values in those % yield to GU point conversion tables are derived?
I guess this isn't necessary to understand for the brewing process, but i figured someone on here may be able to come up with an answer.
THANKS