A protein boost?

[November]

Peter,

I'm sorry to say, that doesn't make any sense.  The example he gave results in 12.48% protein, not 12.6%.

- red.november

[November]

Here's the math, fully worked out, based on Tom's example:

100 lb. flour - 1% = 99 lb.
99 lb. flour w/ 12% protein = 11.88 lb. protein
1 lb. VWG w/ 60% protein = 0.6 lb. protein
11.88 + 0.6 = 12.48
12.48 lb. / 100 lb. = .1248 or 12.48%

I'm not aware of a purely algebraic solution, which is why I calculate the proportions using differential calculus.  I don't think Tom realizes how off these percentages can be based on this type of calculation.  I do find it interesting that he now states the VWG should replace the flour, which is what I conjectured might be the case, but it's still not very accurate.

EDIT:

Just as an added illustration of this method's level of inaccuracy, here's a real-world example: Take KA All-Purpose Flour (11.7%) and try to bring the protein level up to that of Sir Lancelot Flour (14.2%).  Using the proposed calculation would only yield 13.7%.

[Pete-zza]

According to calorie-count.com, Hodgson Mill VWG is 66.6% protein.  Reported at 12 gram increments, that percentage may not be perfectly accurate, but even still, it looks like 60% remains a mythical percentage.  I'm going to go ahead and add Hodgson Mill to the list on the tool.  If someone procures a different protein percentage, let me know.

http://www.calorie-count.com/calories/item/89233.html

November,

I received a voicemail message today from a customer service rep at Hodgson Mill and the percentage protein (66.6%) you found at the calorie-count.com website is indeed correct. It is also consistent with the nutritional data given for Hodgson's VWG at its website (8 grams per serving of 12 grams).

Peter

[November]

Peter,

In that case, I wish Tom would have included his source for the 60% value along with his explanation.  It's bad enough using an inaccurate method for calculation, but to use a percentage that can't be confirmed in the general marketplace amplifies the problem.

Thanks for the information.

- red.november

[Pete-zza]

I passed on November's calculations to Tom Lehmann and also noted that different consumer brands of VWG seem to have higher protein content than 60%. This was his reply, which came in this morning:

The 0.6% is just a rule to follow for figuring the total protein content of the flour. It is not exact/precise as all rules are. Figure it either way and you will be close enough. As for the protein content of a consumer pack of VWG this is the TOTAL protein content of the material in the bag and it is not representative of just the gluten forming proteins (roughly 60%). Not all wheat proteins are gluten forming. Of the seven main proteins in wheat, only two are gluten forming (glutenin and gliadin).
Tom Lehmann/The Dough Doctor

Peter

[November]

I take issue with the proposition that "all" rules are inexact or imprecise.  This one just happens to be.  The point about the gluten forming protein versus total protein was one I brought up before: "Is it from multiplying the percentage of gluten with the percentage of protein (i.e. .75 x .80)?" (http://www.pizzamaking.com/forum/index.php/topic,4252.msg35485.html#msg35485)  But it doesn't make a solid case for using 0.6, because the total protein in flour is the percentage you're trying to boost, not the gluten.  The gluten percentage in 12.7% protein flour is much lower than 12.7%, and varies among brands, so if that's his reasoning, he would also have to consider the gluten level in the flour and not just the protein level.

- red.november

[November]

Here's something to keep in your notes.  Although I thought an algebraic solution was reasonable given the variables, I was not aware of one, that is until I spent some more time thinking about it this morning.  It actually kind of bugged me that there wasn't a simpler solution, so I worked out the differential rate in reverse and came up with a reasonable formula that anybody should be able to use.  Peter, feel free to share this with Tom.

Attached is an image of the formula for clarity.  It should work fine for all the scenarios I gave earlier.  Key: MVWG is the mass of the target amount of VWG, PT is the percentage (in decimal form) of protein in the target combination, PF is the percentage of protein in the starting flour, PVWG is the percentage of protein in the VWG, MT is the mass of the target combination.  Example:

500g flour w/ 14.2% protein is the target, 12.7% protein is in the starting flour, and 75% protein is in the VWG.
(0.142 - 0.127) / (0.75 - 0.127) = 0.0240770465
0.0240770465 * 500 = 12.0g VWG
500 - 12 = 488g flour

- red.november

[Pete-zza]

It’s been a while since I last read anything by Tom Lehmann about how to supplement a particular flour with a particular protein content with vital wheat gluten to achieve a final flour with a desired, higher protein content. I also wondered whether he would use the information that I provided to him (via email) after November created the Mixed Mass Percentage Calculator at http://tools.foodsim.com/, and for which I provided the link to Tom.

Apparently, Tom continues to use the 0.6 rule that he has advocated all along, as noted by a recent post at the PMQ Think Tank at http://thinktank.pmq.com/viewtopic.php?p=23630#23630. For convenience, I have copied and pasted below the pertinent part of that post that applies to the determination of vital wheat gluten amounts:

For every 1% vital wheat gluten that you add to your flour, you will increase the overall protein content by roughly 0.6%, so, lets say that you have 22.5 Kg of flour at 11% protein content, and you add 1% (225 grams) of vital wheat gluten to the flour, the protein content is now at 11.6%. If you want to increase the protein content to say, 13% you would need to add 3.3% (743 grams) of vital wheat gluten to the flour.

I ran Tom’s numbers for the two examples noted above through November’s tool, using the Gilco brand of vital wheat gluten, which is a commercial product sold to professional bakers, and got 210.9 grams of vital wheat gluten for the 11.6% example, and 703.1 grams of the vital wheat gluten for the 13% example. Had I used the Bob’s Red Mill brand of vital wheat gluten I would have gotten the same results because its protein percent (75%) is the same as the Gilco brand. Using either the Arrowhead Mills or Hodgson’s brand of vital wheat gluten, I would have gotten numbers higher than Tom’s because of the lower protein percent (65% and 66.6%, respectively) of those two brands. As noted previously, Tom has stated that the 0.6 rule is just a rule and whether one uses the 0.6 rule or a more accurate one, the results will be close enough.

I believe Tom also forgot to mention in his post that the amount of the base flour, 22.5 Kg in this case, should be reduced by an amount equal to the calculated vital wheat gluten quantity so that the total weight remains the same. However, he did mention that one should add more water to compensate for the addition of the vital wheat gluten.

Peter

[November]

Off by around 6% (or more) is close enough and I'm the King of Scotland.  Thanks for the update, Peter.

- red.november

[Pete-zza]

November,

For the ranges we are talking about, maybe a "0.546 rule" would be a better one to use than 0.6  .

Peter

[csacks]

I am finding all the calculations to be overwhelming.  I have a package of Bob's Red Mill vital wheat gluten flour in front of me.  On the label...Bob's vital wheat gluten is 75 to 80% protein.  Add about one tablespoon per cup of flour in your bread recipe to improve texture and elasticity and help your bread rise.

I have used Hogsdon Mills before and I believe that it said to add 1 to 2 teaspoons per loaf of bread(bread machines) .  At any rate it will tell you on the label how much to use.  What I did was to add the VWG to my measure and add the flour on top.  (Replacing VWG 1 to 1 with flour) I used the same weight as before.  I like using VWG and like whatever the final taste is representative of, be it flour or VWG.

[Pete-zza]

Craig,

I go through the math because I enjoy the process. However, when I am using vital wheat gluten to supplement another flour, I go directly to November's Mixed Mass Percentage Calculator at http://tools.foodsim.com/. There are five different brands of vital wheat gluten in the pull-down menu. The results using that tool will be more accurate than using the recommended volumetric measurements that are given on the packaging for vital wheat gluten products because those recommendations are generic, that is, without regard to the flour to be supplemented by the vital wheat gluten or the protein content of that flour. Following the package instructions shouldn't get you into trouble. The results will just be less accurate in most cases.

Peter

[csacks]

I enjoy the exactness of all the threads that I read.   It is appreciated.  But sometimes I just want to GET-R-DONE.  CraiG