Oat Flour vs Soy Flour: The Ultimate Verdict

For all vegan and gluten-free baking enthusiasts, oat flour and soy flour are two ingredients that have earned their place in plant-based baking, delighting taste buds and boosting nutrition along the way. Oat flour brings a down-to-earth rustic feel, while soy flour takes the spotlight for its remarkable protein boost. 

We’re about to find out how they elevate vegan and gluten-free bakes with their unique qualities in this article.

Comparing oat flour vs soy flour

	Oat Flour	Soy Flour
Substitution ratio vs all-purpose flour	100% swap with all-purpose if done by weight. If done by cup, you need 1 ⅓ cup of oat flour for every 1 cup of all-purpose	Swap 30% of your all-purpose flour for soy flour.
Gluten-free?	Yes*	Yes
Keto-friendly?	No	Yes
Paleo-friendly?	No	No
Allergens	None	Soy
Liquid absorbency	High	High
Pantry shelf life (unopened/sealed)	2 months	3 – 6 months
Best for baking…	Dense baked goods like pancakes, bread, and muffins	Very dense baked goods like cakes and rolls, fudge, and pies.

*Check the label/ingredients to determine gluten-free status

Differences between oat flour and soy flour

Oat flour is not only gluten-free but also free from common allergens like nuts and dairy, which is good news for people with food sensitivities. And while soy has so many fantastic benefits, it won’t be suitable for baking if you have any soy allergies.

Now, let’s talk about dietary preferences. Oat flour may not be suitable for keto or paleo diets due to its higher carbohydrate content. But on the flip side, soy flour is both gluten-free and keto-friendly. Like oat flour, though, it’s not a paleo-friendly flour.

If you’re looking to sub out all-purpose for one of these flours, note that oat flour can often be used as a 1:1 replacement for wheat flour in many recipes, while only up to 30% of all-purpose should be replaced with soy flour. When it comes to liquid absorbency, both flours soak up liquid like sponges, so you might need to make a few adjustments to get the right consistency. Soy flour, in particular, has a strong thickening quality.

Note: Always choose certified gluten-free oat flour if you are gluten intolerant since some oats are processed on machinery that also handles gluten.

Baking with oat flour vs baking with soy flour

Baking with oat flour adds a moist and tender texture to baked goods, giving you goodies that are soft and chewy. The flavor of oat flour brings a hint of nuttiness and subtle sweetness, and a nice golden hue to your baked treats. For many classic recipes like cookies, muffins, or quick breads, oat flour can add that comforting touch.

Using soy flour can lead to a denser texture, but this can be balanced by using it in combination with other flours. As for flavor and color, soy flour is quite similar to oat flour, providing a sweetness and browning. Just like oat flour, soy can be used in almost any recipe and is ideal if you want to add some extra nutritional qualities and depth to your bake.

Ingredients in oat flour vs soy flour

Both flours are single-ingredient flours – oat flour is made from ground oats, while soy flour is made from ground soybeans!

Oat flour + soy flour nutritional facts

Per ¼ cup serving	Oat flour	Soy flour
Calories	120	140
Carbs	22 g	10 g
Fiber	3 g	3 g
Sugar	0 g	0 g
Fat	2 g	6 g
Protein	4 g	12 g
Glycemic index score	44	25

Soy flour and oat flour have many differences in their nutritional makeup. While they do have the same fiber content (3g per ¼ cup) and sugar content (0g per ¼ cup), soy flour is 4x higher in protein (4g vs 12g!) and has less than ½ the carbohydrate content as oat flour does (22g vs 10g). That makes it one of the lowest carb flours around and one that is jam-packed with protein. As a high-protein flour, your baked goods will be filling and teeming with texture. 

Oat flour has a lower fat content at 2g vs 6g and is slightly lower in calories than soy flour (120 vs 140).

Oat flour vs soy flour storage

Oat flour typically has a shorter storage life of around 2 months, while soy flour can last for 3 to 6 months. The shorter shelf life of oat flour is due to its higher fat content, which can lead to rancidity over time if not properly stored. Soy flour has some natural preservation qualities that help extend its shelf life and maintain freshness.

Oat flour vs soy flour: What’s the verdict?

Oat flour and soy flour are two of the most widely used and best vegan flours in the plant-based realm. My personal verdict is that each flour can play a big role in your kitchen – oat flour brings versatility and can act as a pantry staple for many vegan bakers. Meanwhile, soy flour is an amazing way to add a ton of protein to various treats and provide a robust texture.

If you’re interested in experimenting with other types of flour in your baking, we’ve broken down 61 different flours.

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