TLDR: These metrics can give you an idea of how a flour will perform during baking or cooking, but it is nowhere near a complete picture of what a flour is capable of. The best way to tell how a flour performs is to use it.

Here we are going to get into the weeds a bit when it comes to wheat and grain by digging into what these markers mean and how you can use them to more confidently purchase flour.

Protein

Wheat contains a good bit of protein. On average, 1/4 cup of wheat berries contains 6 grams of protein or around 10% of the recommended daily intake for most Americans. That's great news for us from a nutritional standpoint. Two of the big proteins that make up a wheat berry's total protein content are glutenin and gliadin which make up the wonderful, air-trapping, matrix known as gluten. It is because of this that many people associate a flour's protein percentage with its potential gluten strength.

Cake flour is the most delicate and has the lowest protein levels, generally ranging between 5-8%. This makes it great for cakes, cookies, pie dough, and most other sweet applications that don't utilize a biological leavening agent like yeast or sourdough starter.

All-purpose flour generally falls in the 9-11% range when it comes to protein, which makes it a versatile option for many applications but may not have enough strength for longer fermentations powered by yeast or a sourdough starter. 

Bread flour is the strongest of the most common types of flour you'll find in your grocery store and therefore boasts a higher protein percentage, generally 12-14%, and are best suited for bread or bread-adjacent applications that require the dough to hold onto gas created during fermentation. 

The tricky part here is that this metric mostly tracks with gluten strength but it is by no means a guarantee. I've used flour that clocked in at 9% protein that turned out to be one of the best flours I've ever used when baking bread. You're probably safe following this, but the numbers don't reveal the whole truth.

Ash Content

As we've discussed in previous posts, the wheat berry has a few different major components: The bran, the germ, and the endosperm. All of these parts contain minerals, but the large majority of the mineral content in the wheat berry is contained in the germ and the endosperm. One of the ways that laboratories will test for a flour's mineral content (aka, how much bran and germ are present) is they take a sample of the flour, weigh it, and incinerate it under controlled conditions. After the test they weigh what remains (the ash) and compare it to the starting weight and express the difference in a percentage. 

A wheat berry in its whole state contains about 1.5 – 2% ash whereas pure endosperm contains approximately 0.35% ash. Since the largest portion of the wheat berry is endosperm but most of the ash is contained in the bran and germ we can get a good idea of how much of the bran and germ was in the starting sample of flour by looking at its ash content. 

At Raising Oxen we do not sift any of our flours at all so you can expect all of our ash contents to fall between 1.5 – 2%

Falling Number

A flour's falling number tells you about its enzymatic activity. It's a way of revealing whether the farmer harvested the grain at the right time. If wheat is left too long in the field the enzymes in the wheat berry will begin to activate and break down the carbohydrates present. This is important for a couple of reasons: a flour with an abundance of enzymatic activity will ferment very quickly because the complex carbohydrates in the starch have already been broken down to more simple sugars which are quickly consumed by yeast. This is a problem for bakers because one of the most crucial parts of working with fermented doughs is creating an environment in which you can line up gluten development with fermentation activity. If the fermentation happens too fast the gluten may be underdeveloped and unable to hold onto the gas created during the fermentation process, leading to flat and gummy baked goods. 

Another potential problem for bakers is the fact that all of these simple sugars greatly contribute to browning. If you have too many of these simple sugars available, the outside of your baked goods will burn before the inside is fully cooked. Not delicious.

To ascertain this number a laboratory will mix flour with water to form a slurry and place the mixture in a test tube. A plunger or something similar is then placed in the test tube at the top and timed to measure how many seconds it takes to reach the bottom. Generally, you are looking for 400 seconds or greater for wheat. More research needs to be done for other grains like rye, spelt, and einkorn though. 

This is actually an experiment you can do at home, although it may be a little harder to control the variables completely.

How to Use These Numbers

You can get even more technical and granular than this if you like; scientists are quantifying and correlating just about everything these days and to be sure, more needs to be done. To reiterate, these numbers are helpful but they by no means tell the full story of how a flour is going to perform. The only way to truly understand how it will act is to use it. Take note of its texture, how it smells, how well it bakes and browns, does fermentation seem to happen faster or slower. Experimentation is part of the joy of baking and I hope after reading this you feel more empowered to do so.