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While what you describe could be accurately described as sparging, I believe your "definition" is too restrictive.
Wikibrew (certainly not the gospel) states
"All sparges work on the basic principle of moving stuff (we are looking at sugars here) from places of higher concentration (the crushed malt) to places of lower concentration (the sparge water). How we manipulate this determines the sparge technique that we use." In simple terms, sparging or lautering is the rinsing of sugars from the grains. There are multiple ways to achieve that objective.
At the end of a mash, you shouldn't have significant concentration gradients within the mash. Simply draining wort from the grain mass does not create a concentration gradient between the retained wort and the drained wort. Concentration gradients are created by adding plain water to the mash. In the case of batch sparging, the concentration gradient is short lived (it's demise is hastened by stirring.) In continuous (fly) sparging, concentration gradients exist for the duration of the concurrent sparge and lautering processes, although the gradients are continuously changing. Lautering is the separation of the spent grain from the wort, whether there is sparging involved or not. Sparging is removal, by rinsing, of sugars left in the spent grain,
after an initial draining. Rinsing is the reduction of residuals due to the action of dilution (which creates concentration gradients.) Sparging and lautering are not the same thing, even though they may be going on at the same time. In a full volume mash, there is no rinsing of residual sugar from the grain mass after the initial drain, so there is no sparge.
I haven't done the extensive research to back my statements, so I'll accept that they may not be definitive. demonstrably false is bit of a harsh description. In your cited earlier post, you stated "There are many different ways to brew, that all work, and meet the needs of the brewers that use them."You are taking your simulations as gospel and implying that they are 100% accurate and without doubt. I'm not saying whether they are accurate or not, but I can't simply accept them as the definitive truth. We all have opinions. You appropriately corrected me for implying that my opinion was "fact", yet it seems like you have done the same thing.
"Demonstrably false" is the correct description of the assertion that "full volume mashing provides better efficiency than sparging." I will now proceed to demonstrate the falsity of that assertion, thus demonstrating that "demonstrably false" is correct. Unless you can find fault with the physics and math below, the discussion is over. If you don't understand everything that follows, you have no credibility to criticize it. If you have questions about the details, ask specific questions, and I will do my best to provide better, or more detailed, explanations.
If you identify any errors, please provide specific details that show why they are errors. I want to make this simulator as accurate as possible.
First we'll look at the lauter efficiency of a full volume mash, using some arbitrary, but realistic, choices for grain weight, water volumes, grain absorption rate, etc. All volumes will be measured/calculated at 68˚F. The starting point is:
- Grain bill of 10 lbs, 4% moisture content, @ 80% extract potential (dry weight basis)
- Total brewing water volume of 8 gal
- Grain absorption rate of 0.08 gal/lb (typical for a squeezed grain mass)
The dry weight of the grain is:
Dry_Wt = As_Is_Wt * (1 - Moisture_Content) = 10 lbs * 0.96 = 9.6 lbs
The extract (mostly sugar) potential is:
Potential_Extract_Wt = Dry_Wt * Extract_Potential = 9.6 lb * 0.80 = 7.68 lb
We will assume 100% conversion efficiency during the mash, so that our actual Extract_Weight = Potential_Extract_Weight = 7.68 lbs.
Water density at 68˚F is 8.3304 lb/gal, so our 8 gal of water weighs 66.64 lb. We also have the water from the moisture content of the grain. This is 10 lb * 0.04 = 0.4 lb. Thus our total mash water will be:
Mash_Water_Wt = Strike_Water_Wt + Grain_Water_Wt = 66.64 lb + 0.4 lb = 67.04 lb
So, at the end of the mash the wort will contain 7.68 lb of extract and 67.04 lb of water. It is assumed that the mash has been stirred to the point that there are no concentration gradients in the wort. We have the following:
Wort_Wt = Water_Wt + Extract_Wt = 67.04 lb + 7.68 lb = 74.72 lb, and
Wort ˚Plato = 100˚ * Extract_Wt / Wort_Wt = 100˚ * 7.68 lb / 74.72 lb = 10.28 ˚Plato
The volume of wort obtained by lautering is:
Lautered_Wort_Vol = Strike_Volume - (Grain_Wt * Grain_Absorption_Rate) = 8.0 gal - (10 lb * 0.08 gal/lb) = 7.2 gal
We now have to convert ˚Plato to SG so that we can calculate the weight of the 7.2 gal of collected of wort. The equation for conversion is:
SG = 1 + (˚Plato / (258.6 - ((˚Plato / 258.2) * 227.1))), so
10.28 ˚Plato ==> 1.0412 SG
We determine the Lautered_Wort_Wt as:
Lautered_Wort_Wt = Lautered_Wort_Vol * 8.3304 lb/gal * Wort_SG = 7.2 gal * 8.3304 lb/gal * 1.0412 = 62.45 lb
The extract weight recovered is:
Lautered_Extract_Wt = Wort_˚Plato * Lautered_Wort_Wt / 100˚ = 10.28 * 62.45 / 100 = 6.42 lb
For lauter efficiency we have:
Lauter_Efficiency = 100% * Lautered_Extract_Wt / Extract_Wt = 100% * 6.42 lb / 7.68 lb = 83.6%, and Mash_Retained_Extract_Wt = Extract_Wt - Lautered_Extract_Wt = 7.68 lb - 6.42 lb = 1.26 lb
Whew, we're finally done the the full volume, no-sparge part of the analysis. Now we'll look at an equal runnings volume, single batch sparge for the same grain bill, moisture content, extract potential, total brewing water (8.0 gal), and conversion efficiency as we used for the no-sparge. The actual total Extract_Wt is the same 7.68 lb as before. The total brewing water will be split into 4.4 gal of strike water, and 3.6 gal of sparge water. The analysis of the mash and first runnings is similar to the full volume case:
Our 4.4 gal of strike water weighs 36.65 lb. We have the same 0.4 lb of water from the grain. Thus our total mash water will be:
Mash_Water_Wt = Strike_Water_Wt + Grain_Water_Wt = 36.65lb + 0.4 lb = 37.05 lb
So, at the end of the mash the wort will contain 7.68 lb of extract and 37.05 lb of water. It is assumed that the mash has been stirred to the point that there are no concentration gradients in the wort. We have the following:
Wort_Wt = Water_Wt + Extract_Wt = 37.05 lb + 7.68 lb = 44.73 lb, and
Wort_˚Plato = 100˚ * Extract_Wt / Wort_Wt = 100˚ * 7.68 lb / 44.73 lb = 17.17 ˚Plato
The volume of wort obtained by lautering is:
Lautered_Wort_Vol = Strike_Volume - (Grain_Wt * Grain_Absorption_Rate) = 4.4 gal - (10 lb * 0.08 gal/lb) = 3.6 gal
We now have to convert ˚Plato to SG so that we can calculate the weight of our 3.6 gal of wort. The equation for conversion is:
SG = 1 + (˚Plato / (258.6 - ((˚Plato / 258.2) * 227.1))), and
17.17 ˚Plato = 1.0705 SG, and
Lautered_Wort_Wt = Lautered_Wort_Vol * 8.3304 lb/gal * Wort_SG = 3.6 gal * 8.3304 lb/gal * 1.0705 = 32.10 lb
The extract weight recovered is:
Lautered_Extract_Wt = Wort_˚Plato * Lautered_Wort_Wt / 100˚ = 17.17 * 32.10 / 100 = 5.51 lb
Mash_Retained_Extract_Wt = Extract_Wt - Lautered_Extract_Wt = 7.68 lb - 5.51 lb = 2.17 lb
We now need to determine the water weight in the mash after adding the sparge water, To do this we need to calculate the weight of water retained in the mash. Since:
˚Plato = 100˚ * Extract_Wt / (Extract_Wt + Water_Wt), then
Retained_Mash_Water_Wt = Retained_Mash_Extract_Wt * 100˚ / ˚Plato - Retained_Extract_Wt, ==>
Retained_Mash_Water_Wt = 2.17 lb * 100˚ / 17.17˚ - 2.17 lb = 10.47 lb
The total Sparge_Mash_Water_Wt then becomes:
Sparge_Mash_Water_Wt = Retained_Mash_Water_Wt + Sparge_Water_Wt
= 10.47 lb + 3.6 gal * 8.3304 lb/gal = 40.46 lb
Now that we now how much extract and water are in the sparged mash, we can calculate the Sparged_Wort_˚Plato as:
Sparged_Wort_˚Plato = 100˚ * Mash_Retained_Extract_Wt / (Mash_Retained_Extract_Wt + Sparge_Mash_Water_Wt)
= 100˚ * 2.17 lb / (2.17 lb + 40.46 lb) = 5.09 ˚Plato
The volume of wort obtained by lautering the sparge is 3.6 gal, the same as the sparge water volume, since there is no additional grain absorption during the sparge. The ˚Plato of the sparged wort is converted to SG using the formula above:
Sparged_Wort_˚Plato = 5.09 ==> Sparged_Wort_SG = 1.0200
The Sparged_Wort_Wt then becomes:
Sparged_Wort_Wt = Sparged_Wort_Vol * 8.3304 lb/gal * SG = 3.6 gal * 8.3304 lb/gal * 1.0200 = 30.59 lb
And the Sparged_Extract_Wt is:
Sparged_Extract_Wt = Sparged_Wort_Wt * Sparged_Wort_Plato / 100 = 30.59 lb * 5.09 / 100 = 1.56 lb
And the total collected extract is:
Total_Collected_Extract_Wt = First_Runnings_Extract_Wt + Sparged_Extract_Wt = 5.51 lb + 1.56 lb = 7.07 lb
This is more than the 6.42 lb of extract collected with the no-sparge process.
For lauter efficiency we have:
Lauter_Efficiency = 100% * Total_Collected_Extract_Wt / Extract_Wt = 100% * 7.07 lb / 7.68 lb = 92.1%
92.1% lauter efficiency for single batch sparge vs. 83.6 lauter efficiency demonstrates that full volume, no-sparge mashes
do not have better efficiency than batch sparged mashes.
You can change the grain weights, total brewing water volumes, and grain absorption around all you want, but the resulting conclusion of which process has better efficiency remains the same, as long as you keep the inputs the same within a case, and only change the sparging process. This is what I did to create the chart posted earlier in this thread.
In your cited earlier post, you stated "There are many different ways to brew, that all work, and meet the needs of the brewers that use them." You are taking your simulations as gospel and implying that they are 100% accurate and without doubt. I'm not saying whether they are accurate or not, but I can't simply accept them as the definitive truth.
I don't claim that the simulations are 100% accurate, but they are accurate enough to prove that the efficiency with a sparge is better than without. There is no doubt about the accuracy of the dilution math used in the model. Things that could affect the accuracy of the model are errors in grain potentials, moisture content, grain absorption rates, the assumption that grain absorption is equal for all runnings, and the assumption of no concentration gradients within in the wort before lautering, but none of these will affect the comparison between sparge vs. no-sparge, since the differences aren't even close.
We all have opinions. You appropriately corrected me for implying that my opinion was "fact", yet it seems like you have done the same thing.
The bottom line is to take everything you hear as guidance, not fact.
Some things are facts (gravity, and the physics that describe the behavior of objects in our universe, for example), and some things are opinions or value judgments. Opinions and value judgments are debatable, facts are not. You need to be able to tell which is which. In the case of the present discussion, the physics of dilution are fact.
Brew on
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