Protein content of flour

Fact is, at least in the US, there are no regulations on the labeling of flour as ap, bread, etc., at least as far as protein content is concerned.

Examples: White Lily AP flour is about 8% protein, while King Arthur AP is 11.7%. Of course many think of 8% as cake flour, and 11.7% as a not too shabby bread flour.

If you can, forget the "labeling" as to the why and how, and find what flours you prefer, and use those. If you really must know the precise protein%, this can only be obtained from those with the wherewithall to perform the analysis(manufacturers, etc). Many do publish such info, but are only (probably) required to be within the range on the nutrition label. Some companies, like King Arthur, pledge to maintain their published, precise levels.

AS far as the nutrition labels as the souce of info for the protein level, because of rounding, it can only give you the possible range. In the flour you mentioned, that "3" grams in 30, could actually be 2.5 grams, or it could be 3.4 grams.

2.5 / 30 = 8.3%     3.4 / 30 = 11.3%

So your flour could be 8.3%, 11.3%, or anywhere in between.

I tend to think of KAAP as the(my) reference standard for "bread flour" as that is what they prescribe for most of their yeast "bread" recipes. Having said that, I use White Lily Bread flour, because in my area, it is less than half the cost of KA and is known(supposedly) to have the same protein% as KAAP. Whatever the levels, it makes great breads, for me. But I imagine many others would also. I just have not had occasion to try them.

Again, the main thing is, just find a flour that works for you. And if you are trying to find the precise levels for store brand, private label, etc., you can pretty much forget that.

We live in Indiana but we travel quite a bit throughout SC, GA, and Florida. Does Anyone know where we can purchase White Lilly bread flour. Right now we purchase KAAP, Sir Lancelot, and KABF in 50# bags.

Protein for propriety brands will always maintain/meet an average. Contact them, they should never fall/rise above a certain value range. As for millers, it will change per batch of flour. I'm not sure about the laws in the US.

As for 10% protein flour, it would not be used for 'bread' (tall-rising), let alone labelled 'bread flour' here in the UK, it should never fall below 12% protein, so you're right to be suspicious. Though here and in Europe, naturally local softer wheat is cut with 'super strong' flour.

I did a lot of Googling to put this list together.

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FLOUR PROTEIN BY TYPES AND BRANDS (retail flour):
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CAKE FLOUR - 7% to 9.4% protein
Best Use: cakes, blending with national brands all-purpose flour to make pastry flour or Southern flour substitute.
-King Arthur Queen Guinevere Cake Flour, 7.0%
-King Arthur Unbleached Cake Flour Blend, 9.4% 
-Pillsbury Softasilk Bleached Cake Flour, 6.9%
-Presto Self Rising Cake Flour, 7.4%
-Swans Down Bleached Cake Flour, 7.1%
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PASTRY FLOUR - 8 to 9% protein
Best Use: biscuits, cookies, pastries, pancakes, pie crusts, waffles.
-King Arthur Unbleached Pastry Flour, 8%
-King Arthur Whole Wheat Pastry Flour, 9%
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ALL-PURPOSE FLOUR, SOUTHERN - 8 to 9% protein
Best Use: biscuits, cookies, muffins, pancakes, pie crusts, quick breads, waffles.
-Martha White Bleached All-Purpose Flour, 9%
-White Lily Bleached All-Purpose Flour, 8 to 9%
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SELF-RISING FLOUR (flour, baking powder, salt) - 8 to 10.5% protein
Best Use: biscuits, cookies, pancakes, muffins, quick breads, waffles. 
-Gold Medal Bleached Self-Rising Flour, 10.5%
-King Arthur Unbleached Self-Rising Flour, 8.5%
-Martha White Bleached Self-Rising Flour, 9.4%
-Pillsbury Best Bleached Self-Rising Flour, 9.7%
-Presto Self Rising Cake Flour, 7.4%
-White Lily Bleached Self-Rising Flour, 8 to 9% 
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ALL PURPOSE BAKING MIXES (flour, shortening, baking powder, sugar, salt) - 6.25 to 12.5% protien
Best Use: biscuits, cookies, coffee cakes, pancakes, quick breads, pastry, waffles
-Arrowhead Mills All Purpose Baking Mix, 12.5%
-Bisquick Original Baking Mix, 7.5%
-Jiffy All Purpose Baking Mix, 6.25%
-King Arthur Flour All Purpose Baking Mix, 10%
-Pioneer Original Baking Mix, 7.5%
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INSTANT FLOUR 10.5 to 12.6% protein
Best Use: thicken gravies, sauces, and soups without lumps.
-Gold Medal Wondra Quick Mixing Flour, 10.5%
-Pillsbury Best Shake & Blend Flour, 12.6%
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ALL-PURPOSE FLOUR, BLEACHED & UNBLEACHED, NATIONAL BRANDS - 10 to 11.5% protein
Best Use: makes average biscuits, cookies, muffins, pancakes, pie crusts, pizza crusts, quick breads, waffles, yeast breads.
-Gold Medal All-Purpose Flour, 10.5%
-Pillsbury Best All-Purpose Flour, 10 to 11.5%
-Pioneer All-Purpose Flour, 10%
-White Wings All-Purpose Flour, 10%
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ALL-PURPOSE FLOUR, NORTHERN, BLEACHED & UNBLEACHED - 11.5 to 12% protein
Best Use: cream puffs, puff pastry, yeast breads, pizza crusts.
-Heckers and Ceresota All-Purpose Flour, 11.5 to 11.9 %
-King Arthur All-Purpose Flour, 11.7%
-Robin Hood All-Purpose Flour, 12.0%
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BREAD FLOUR - 12 to 13.3% protein
Best Use: traditional yeast breads, bread machine, pizza crusts, pasta.
-Gold Medal Better For Bread, 12% 
-King Arthur Unbleached Bread Flour, 12.7%
-Pillsbury Best Bread Flour, 12.9%
-White Lily Unbleached Bread Flour, 11.7%
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DURUM WHEAT (Semolina) 13 to 13.5% protein
Best Use: Pasta.
-Hodgson Mill Golden Semolina & Extra Fancy Durum Pasta Flour, 13.3% 
-King Arthur Extra Fancy Durum Flour, 13.3%
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WHOLE WHEAT FLOUR - 12.9 to 14% protein
Best Use: hearth breads, blending with other flours.
-Gold Medal Whole Wheat Flour, 13.3%
-King Arthur 100% Whole Wheat Flour, 14%
-King Arthur 100% White Whole Wheat Flour, 14%
-Pillsbury Best Whole Wheat Flour, 12.9%
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HIGH-GLUTEN FLOUR 14 to 15% protein
Best Use: bagels, pizza crusts, blending with other flours.
-King Arthur Organic Hi-Gluten Flour, 14% 
-King Arthur Sir Lancelot Unbleached Hi-Gluten Flour, 14.2%
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VITAL WHEAT GLUTEN FLOUR, Breadmaking Supplement - 65 to 77% protein
Best Use: Added to raise gluten. Adds extra gluten to low-gluten whole grain flours, such as rye, oat, teff, spelt, or buckwheat.
-Arrowhead Mills Vital Wheat Gluten Flour, 65.0% 
-Bob's Red Mill Vital Wheat Gluten Flour, 75.0%
-Gillco Vital Wheat Gluten Flour, 75.0%
-Hodgson Mill Vital Wheat Gluten Flour, 66.6%
-King Arthur Vital Wheat Gluten Flour, 77.8%
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Retail Flour Companies - Brands:
-Bob’s Red Mill Natural Foods, Milwaukie, Oregon -Bob's Red Mill 
-C.H. Guenther & Son Inc, San Antonio, Texas - Pioneer Flour, Pioneer Baking Mix, White Wings Flour
-General Mills Company, Minneapolis, Minnesota - Bisquick, Gold Medal Flour, (sold US Pillsbury Flour , retains Pillsbury frozen goods)
-Hain Celestial Group Inc, Boulder, Colorado - Arrowhead Mills
-J.M. Smucker Company, Orrville, Ohio - Martha White Flour, Pillsbury Flour, Robin Hood Flour, White Lily Flour
-King Arthur Flour Company, Norwich, Vermont - King Arthur Flour
-Reily Foods Company, New Orleans, Louisiana - Swan's Down Cake Flour, Presto Self Rising Cake Flour
-Uhlmann Company, Kansas City, Missouri - Heckers Flour, Ceresota Flour
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10 g protein to 30 g serving size would be anything other than 10% ?  I can see it legally being 10.49%   But not 12%.  If it was 12% it would easily be bread flour and they would sell it at that for way more money?

I love LaFama AP flour from Mexico for flour tortillas and bread at 13.3% protein but it could be as low as 12.6% - still good bread flour at 4g protein per 30 g serving size.  I also like the price at $1.88 for 5 #'s for LaFama.  I know it feels and performs better than many of the premium flours at 3 times the price.

The Desert Durum I recently found was 14.7 % protein and the best durum ever - very tough to get though.

I just stumbled on this today. Looks like a lot of work on those listings

I am trying to make my grandmother’s Easter bread recipe.  I have learned that she always used Robin Hood flour, and that it is a mixture of hard red wheat and soft wheat.  Could I not then make my own mixture of King Arthur AP flour and White Lily flour?  Any ideas on which proportions to use?  (KA is 11.7% protein and WL is 8%, based on what I could find.)