The Ultimate Guide to Oat Flour (How to Use + Make it)

Learn everything about oats flour with this Ultimate Guide to Oat Flour! It covers: what it is, how to make it, how to use it in baking, substitutes and the best oat flour recipes!

What is Oat flour?

Oat flour is a whole grain flour made by grinding oats into a fine powder. It’s naturally gluten free and packed with nutrients such as calcium, magnesium, iron, thiamine, phosphorus and zinc. It’s higher fibre and protein content not only helps with the structure of baked goods, but also makes them more satiating too. This inexpensive alternative to other gluten free flours and wheat flours can either be store bought or can easily be made at home (see below).

Is oat flour gluten free?

This is a VERY common question but simply put, yes. Oat flour is naturally gluten free but the milling process with other grains is what makes them potentially NOT gluten free due to cross contamination. If you’re celiac and cannot tolerate gluten, just be sure to purchase gluten free oat flour or gluten free rolled oats if making your own.

What does oat flour taste like?

It has a subtle sweet, toasty and nutty flavour. It also adds a lovely faint caramel flavour in baked goods such as cookies and cakes that pairs so well with other ingredients such as:

• nuts
• deep sugars: maple syrup, coconut sugar, brown sugar
• apples
• berries
• bananas
• dried fruit: dates, raisins, cranberries
• spices: cinnamon, nutmeg, all spice
• yogurt
• coffee
• chocolate
• coconut
• vanilla

How to Make Oat Flour

Oat flour is incredibly easy to make. All you need is a high speed blender and some oats! Here’s how I make oat flour:

1. Add 2 cups of rolled oats into a high speed blender (I use a Vitamix) and blend on high for 30-45 seconds. Scrape down the sides and mix it around with a spatula. Then blend again for 15-20 seconds, until as fine and powdery.
2. Optional, but I also dump the flour on a large baking tray to let it cool down since it does heat up in the blender.

To make 1 cup of oat flour (120g), you’ll need 1 1/4 cup of rolled oats (120g).

You can use any kind of oats to make oat flour: steel cut oats, quick oats, groats, flaked oats and large rolled oats.

If you don’t have a vitamix or high speed blender, a strong food processor may also work. However, in my experience it never gets as fine ground as store bought or making it in a high speed blender which can affect the texture of your baked goods dramatically (especially for muffins, pancakes, cakes and cupcakes). In that case, I highly suggest using store bought oat flour for bakes goods that are meant to be light and fluffy and use course ground homemade oat flour for cookies, biscuits and waffles.

Where to Buy Oat flour

Oat flour is much more readily available nowadays! I used to only be able to find it at specialty health food stores but now I can pick some up at my local grocery store. It’s usually in the baking aisle OR where the oats are sold. My go-to store bought oat flour is Bob’s Red Mills.

How to Store Oat Flour

For both store bought and homemade oat flour, store in a air tight container covered in a cool dry place for up to 2 months. After 2 months, the flavour tends to get a little stale. If planning to keep it for longer, you can keep it in the refrigerator for up to 6 months and in the freezer for up to 1 year.

How to Use Oat Flour in Baking

Oat flour is hands down one of my favourite gluten free flours to bake with. The subtle sweet and nutty-caramel like flavour enhances baked goods since it pairs incredibly well with so many other ingredients! It also has the ability to make cakes more tender and delicate and cookies more thick and chewy– thanks to its higher protein and fibre content. 

There are many recipes that call for just oat flour (and there are a lot out there) such as these waffles, mug cakes and muffins with excellent results but it can sometimes be tricky getting the right ratios of wet to dry ingredients. Too much liquid can make things gummy but not enough can cause a crumbly dry mess. 

When paired with other flours, oat flour can help soften and lighten up the texture, give more of a ‘chew’ and help keep baked goods moist since it has the ability to absorb a lot of liquid. 

So to recap, the properties of oat flour:

• Absorbent: retains liquid well, keeps things moist and thick
• Medium Density: has the ability to keep things soft and light but can also make things dense with additional liquid added
• Crumbly: must add a binder or egg to keep things held together
• Flavour: subtle nutty-toffee notes

My go-to oat flour gluten free flour blend:

1. Rice flour, oat flour + a starch: White rice flour is a light flour so keep things extra fluffy and light. Oat flour also also light in nature and also keep things moist, adds tenderness and removes any grittiness that rice flour sometimes leaves. A starch is essential to help bind these flours together since they do not contain any gluten. I’ll typically go to potato starch for fruit heavy recipes (ie. fluffy banana muffins or vanilla cup cakes) since it is a dryer starch and tapioca starch for cakes and cookies. Glutinous sweet rice flour is another great option that not only binds well but makes things more chewy. This blend is great for cupcakes, cake and lighter muffins. 
2. Almond flour, oat flour + a starch: Almond flour adds moisture and makes things slightly more dense when paired with oat flour which is great for breakfast muffins and thicker cookies. Again, the starch is added to help bind the ingredients together. This blend is ideal for cookies, denser muffins and quick breads. 

Tips for Baking with Oat Flour

• Starch & Binders: Above I mentioned starches as a binder but you could also use egg alternatives such as flax eggs, chia eggs or aquafaba. In my experience, these egg substitutes are better suited for things like cookies and denser bakes because they tend to weigh down cakes and muffins since they are heavier. 
• Substitute by WEIGHT not volume: Oat flour tends to be lighter when measured by volume (measuring cups) so you would be missing some dry ingredients that could potentially alter your baked goods and leave them overly moist. 
• Let Batters Rest: This tip is great for muffins and pancakes because it gives the oats time to absorb the liquid which results in a more moist and non gummy crumb. 

Can I use oat flour instead of all purpose flour?

In comparison to all the other gluten free flours, in my experience oat flour behaves the most similarly to wheat flour. However regarding substituting a recipe that calls for all wheat flour– it depends on what you’re baking and the recipe. Like mentioned above, denser baked goods tend to do better with all oat flour versus baked goods with a fluffy crumb like cakes. And since there is no gluten, you will definitely need a binder due to its crumbly nature. So generally speaking, I do not recommend substituting all of the wheat flour for oat flour because it tends to get gummy and dense if not used in the right liquid to dry ratios. Instead, start with recipes that use just oat flour intentionally like these mug cakes, muffins and cookies. 

How much oat flour do I substitute for white flour?

If you’re keen on replacing some of the flour with oat flour, start by swapping 25%-30% of the total amount and experiment from there. 

Oat Flour Substitutes

Oat flour is best substituted with another medium-density gluten free flour such as buckwheat flour, sourgum flour, spelt flour and quinoa flour. I don’t recommend substituting all of the oat flour with heavy flours (almond flour / coconut flour) or light flours (rice flours) because they require different amount of liquid and can make your baked goods dense or gritty. 

I hope you found this Guide to Oat Flour useful and helps with your gluten free baking!

If it’s your just getting into gluten free baking, here are some of my tried and true favourite oat flour recipes to get you started:

• Light & Crispy Oat Flour Waffles (all oat flour)
• Oat Flour Pancakes (oat flour + potato starch)
• Gluten Free Vanilla Cupcakes (oat flour + rice flour)
• Blender Oatmeal Banana Muffins (all oat flour)
• Blueberry Oatmeal Muffins (almond flour, oat flour & tapioca starch)
• Fluffiest Banana Muffins (oat flour, rice flour + tapioca starch)
• Blueberry Chocolate Muffins (oat flour, almond flour + potato starch)
• Lemon Poppy Seed Muffins (oat flour, almond flour + tapioca starch)
• Healthy Chocolate Chip Mug Cake (oat flour)
• Banana Bread Mug Cake (oat flour)
• Cashew Butter Blueberry Oatmeal Cookies (oat flour)
• Matcha Chocolate Chip Cookies (oat four + rice flour)
• Mini Blueberry Galettes (oat flour + almond flour)
• Blueberry Brownies (oat flour + tapioca starch)
• Cashew Butter Blondies (oat flour)
• Pumpkin Chocolate Chip Blondies (oat flour)

More from Gluten Free Baking Series:

• Ultimate Guide to Gluten Free Baking (Introduction)