[S. cerevisiae]

I've always used what Palmer lists in How to Brew, 40-43 points per gallon. 40 is also an easy number to work with as it is easily divisible by 5 or 10 gallons.

That number is easier to use, but using it can lead to a significant error in final gravity if enough DME is added to a batch of wort (e.g., 50% extract from grain/50% DME partial mashes).  I do all of my recipe formulation work in PPG because I track my batch extraction rates as mixed-grist PPG values, not efficiency percentages where every grain in the grist is weighted against a theoretical DBFG value; therefore, these kinds of errors stick out a like a sore thumb. 

[hopfenundmalz]

DME is about 40 points per pound per gallon.

DME carries points per pound per gallon (PPG) value of 46.  DME's PPG value is used to determine the maximum extract possible from a batch of malt based on it's dry basis, fine grind (DBFG) percentage

Briess 2-Row DBFG = 80.5%

Briess 2-Row extract in PPG = 0.805 x 46 = 37 PPG

Hey S.C., never seen that. If you have some information that shows how that is a reference standard, can you share?

The method to determine the extract from a batch of malt is the Congress Mash, which has a procedure for preparing the malt, the fine grind, the water is distilled, the time and temp are specified. And so on.
http://www.brewingwithbriess.com/blog/understanding-a-malt-analysis/

Noonan has some information on malt analysis, too.
http://morebeer.com/brewingtechniques/bmg/noonan.html

The brewers that have mash presses/filters can exceed 100% by a little, as they squeeze the mash and get more liquid out.

I am really looking forward to the Malt book by John Mallett. Now that the Water book is out, I think that malt is the area that is lacking in information.

[Stevie]

number is easier to use, but using it can lead to a significant error in final gravity if enough DME is added to a batch of wort (e.g., 50% extract from grain/50% DME partial mashes).  I do all of my recipe formulation work in PPG because I track my batch extraction rates as mixed-grist PPG values, not efficiency percentages where every grain in the grist is weighted against a theoretical DBFG value; therefore, these kinds of errors stick out a like a sore thumb.

In small scale it won't be that significant.


Example: 15 min before the end of the boil I find I am 8 points shy of my desired OG (bad efficency, lower rate of boil off, whatever). I multiply the 8 by my batch size to get 40. Woah, that's about a pound of DME! Close enough. This isn't surgery and I did it without paper or a calculator.

[denny]

I've always used what Palmer lists in How to Brew, 40-43 points per gallon. 40 is also an easy number to work with as it is easily divisible by 5 or 10 gallons.

FWIW, I've never seen any other source that has it that low.  I count it as 45, because it's easy to divide into a 5 gal. batch.

[HoosierBrew]

In small scale it won't be that significant.


Example: 15 min before the end of the boil I find I am 8 points shy of my desired OG (bad efficency, lower rate of boil off, whatever). I multiply the 8 by my batch size to get 40. Woah, that's about a pound of DME! Close enough. This isn't surgery and I did it without paper or a calculator.

+1.  For years I've used 45pts/lb/gallon (read it somewhere) to correct OGs on occasion - ie., 9 points /lb DME in a 5 gallon batch.  I get to within a point of target this way.

EDIT - Come to think of it I think I got that from you, Denny !

[Stevie]

I've always used what Palmer lists in How to Brew, 40-43 points per gallon. 40 is also an easy number to work with as it is easily divisible by 5 or 10 gallons.

FWIW, I've never seen any other source that has it that low.  I count it as 45, because it's easy to divide into a 5 gal. batch.

Northern Brewer lists it at 40-43 as well. Guessing their source is the same as mine. Actually, the first result in a google search of "DME PPG" was Northern Brewer for me. 45 is simple as well, 43 not as simple.

[HoosierBrew]

Northern Brewer lists it at 40-43 as well. Guessing their source is the same as mine. Actually, the first result in a google search of "DME PPG" was Northern Brewer for me. 45 is simple as well, 43 not as simple.

Yep, in the scheme of things, it's 8 or 9 pts/lb in 5 gallons. At the homebrew scale, just not major.

[S. cerevisiae]

Hey S.C., never seen that. If you have some information that shows how that is a reference standard, can you share?

From what I can ascertain, the dry basis, fine grain (DBFG) percentage values provided by maltsters are based on the percentage of the total weight that can be extracted from a given product.  Briess specs their 2-row malt has having a DBFG value of 80.5% (Extract FG, Dry Basis, http://www.brewingwithbriess.com/Assets/PDFs/Briess_PISB_2RowBrewersMalt.pdf).  Assuming that 100% barley corn conversion would yield 46 PPG (the reference value for pure sugar) leads to the equation 0.805 x 46 = 37 points per pound per gallon (PPG).  If one searches the popular maximum theoretical extract tables for American 2-row, one finds that most spec the malt as having a maximum yield of 37 PPG. 

With that said, I would like to know where some people are getting their maximum theoretical extraction rate tables.  Many of these tables contain values that are a point high or a point low if calculated using the data provided by the maltster and 46 PPG as the reference for 100% conversion of a barley corn to extract.  The inaccuracy found in many maximum theoretical extraction rate tables is why I spec my recipes using mixed-grist PPG values, not efficiency percentages.  Not only are mixed-grist PPG values easier to calculate (batch_gravity_in_points x batch_volume_in_gallons / grist_weight), they are more accurate because they are actual measured values.  With efficiency percentages, the accuracy of a stated efficiency percentage is dependent on the lookup tables of maximum extraction values used by a recipe creator and a recipe user.  This possible impedance mismatch is not a problem if the recipe creator and recipe user are using the same brewing software. However, as the number of brewing software packages grows, so does the possible number of impedance mismatches.

[hopfenundmalz]

Hey S.C., never seen that. If you have some information that shows how that is a reference standard, can you share?

From what I can ascertain, the dry basis, fine grain (DBFG) percentage values provided by maltsters are based on the percentage of the total weight that can be extracted from a given product.  Briess specs their 2-row malt has having a DBFG value of 80.5% (Extract FG, Dry Basis, http://www.brewingwithbriess.com/Assets/PDFs/Briess_PISB_2RowBrewersMalt.pdf).  Assuming that 100% barley corn conversion would yield 46 PPG (the reference value for pure sugar) leads to the equation 0.805 x 46 = 37 points per pound per gallon (PPG).  If one searches the popular maximum theoretical extract tables for American 2-row, one finds that most spec the malt as having a maximum yield of 37 PPG. 

With that said, I would like to know where some people are getting their maximum theoretical extraction rate tables.  Many of these tables contain values that are a point high or a point low if calculated using the data provided by the maltster and 46 PPG as the reference for 100% conversion of a barley corn to extract.  The inaccuracy found in many maximum theoretical extraction rate tables is why I spec my recipes using mixed-grist PPG values, not efficiency percentages.  Not only are mixed-grist PPG values easier to calculate (batch_gravity_in_points x batch_volume_in_gallons / grist_weight), they are more accurate because they are actual measured values.  With efficiency percentages, the accuracy of a stated efficiency percentage is dependent on the lookup tables of maximum extraction values used by a recipe creator and a recipe user.  This possible impedance mismatch is not a problem if the recipe creator and recipe user are using the same brewing software. However, as the number of brewing software packages grows, so does the possible number of impedance mismatches.

Re-reading Palmer, the reference is 100% sucrose (didn't remember that). DME would be close or at 46 pppg. There seems to be some variance when you look on the net for what DME is. I need to make some starters, so time for some measurements later on.
http://www.howtobrew.com/section2/chapter12-3.html