May 6, 2007
Using the formula below and the data for Maris Otter malt , I calculated the ppg (SG of 1 lb of fermentable in 1 gal of water) for the Maris Otter Malt that I used in my bitter 2 recipe.
Key
DBCG = Dry Basis/ Coarse Grind
MC = Moisture Content
Brewhouse Efficiency = Your average home brewery mashing efficiency
S.G. = ((((DBCG – MC – 0.002) * Brewhouse Efficiency * 46.214) * 0.001) +1)
S.G. = ((((0.805 – 0.03 – 0.002) * 0.77 * 46.214) * 0.001) +1)
S.G. = 1.02750703494
This equates to 27.5 ppg for Maris Otter malt in my home brewery. This seemed pretty good to me considering that I used a candy thermometer when mashing my grain, and having to go over all my grain with a rolling pin. I will need to pickup a grain mill in the future so that I can have some consistency with my grain.
I found a formula that allows you to calculate the SG of 1 lb of malt in 1 gal of water based on the Malt Datasheet
http://www.brewingtechniques.com/bmg/noonan.html
“Extract yield measurements: Extract (% DBFG). This acronym stands for extract yield, dry basis, fine grind, and is determined using an ASBC laboratory mash. As mentioned previously, the measurements are adjusted for a uniform 0% moisture content. The fine-grind extract percentage indicates the maximum soluble yield possible for the malt. The higher the DBFG extract, the more soluble the material and the less husk and protein. Any base malt that doesn’t give at least 78% DBFG extract is substandard.
Extract (% DBCG). Whereas DBFG is a measure of the quality of the grain itself, DBCG (extract yield, dry basis, coarse grind) gives a better indication of the degree of starch modification that the grain underwent during malting, and it more closely approximates the crush achieved in the brewhouse. The DBCG rating alerts brewers to the amount of yield they can target (see chart for acceptable ranges). In reality, however, production breweries are not as efficient as lab equipment, so DBCG values need to be reduced by 5-15% to reflect the actual yields likely to be obtained in a given brewhouse.
Brewhouse extract yield can be calculated using the following formula (all percentages are expressed as decimals for purposes of calculation):
Brewhouse Yield = (DBCG – MC – 0.002)
X Brewhouse Efficiency For example, using typical figures:
(0.715 – 0.035 – 0.002) X 0.90 = 0.6102 In this example, actual extract yield to be expected would be 61%.
This calculation can be extended to give the approximate density (as °Plato or specific gravity) that a charge of malt will give to a volume of wort. The extended calculation simply multiplies the yield by a constant to arrive at °P or specific gravity (S.G.) of 1 lb of malt in 1 gal of wort:
°P = (DBCG – MC – 0.002) X Brewhouse Efficiency
X 11.486
S.G. = (DBCG – MC – 0.002) X Brewhouse Efficiency
X 46.214 For example:
S.G. = (0.715 – 0.0035 – 0.002) X 0.90
X 46.214 = 28.1998, or S.G. 1.028.”
I was just playing around with ProMash brewing software. It is neat, but does not perform the calculations to accurately reflect partial mash recipes with regard to high SG boils and hops utilization. The search continues. Overall it is clunky to use (the gui stinks). It looks like it would be useful if you were doing full wort boils (which I can’t). Maybe the software can perform the necessary calculations, but I am using the Demo version so It may be disabled. Regardless of that, if you were trying to sell something, you would Make the demo so that it would work… Right?
April 25, 2007
I received a box from NorthernBrewer containing 4 ounces of Whole Styrian Goldings hops (vaccum packed), an in line hepa filter and a 2 micron stainless steel diffusion stone for wort aeration. (I still need to purchase an air pump. I can’t wait to brew another batch.
April 23, 2007
While I was bottling on Friday, a few bottle caps really did not crimp well onto some bottles. Investigation this afternoon revealed that the capper that I am using does not work well with Guiness, Harp, and Bass bottles because the thick part at the top of the bottle is not long enough. The capper does not have anything it can grab onto while it is trying to crimp the cap. If I can find time tomorrow I will post pictures of a good bottle and a bad bottle side by side.