Why you can’t substitute one ingredient for another in baking: the flour


How many times have I heard “Oh I wish you could make a gluten free croissant, or a gluten free baguette.” Although I’d be delighted to oblige people with dietary restrictions, unfortunately making the real deal without using wheat flour (which contains gluten) is impossible. In some bakeries you can get pretty decent gluten-free alternatives but I still have to eat a gluten free “croissant” that’s as light and flaky as the original recipe, really they’re two different things (hence the ” “).

I’m not a chemist so I don’t know exactly what goes on at the molecular level but I know some basics. And I know I’m always careful when I’m tweaking a recipe.

flour butter sugar eggs

In classic French baking, most desserts and pastries are a combination of the following ingredients: sugar, butter, eggs, flour. Let’s look at each ingredient’s role in baking, starting with flour.

We’re talking about regular all-purpose wheat flour here. I usually stick to unbleached flour because I don’t like the idea of adding unnecessary chemicals to my food (they sell bleached and unbleached in North America, I’m not sure about other countries).

Why do we need flour in traditional baking?

1- Flour gives structure and stability to your bread or pastries.
2- It helps achieve a certain texture depending on how you work it
3- It adds flavour

Flour is responsible for structure, stability and texture because of the gluten it contains. Flour is why your cakes don’t collapse like a souffle when they’re cooling down.

Gluten is a protein that can be found in wheat and other cereals and acts as a binding agent. It’s activated when it binds with water molecules. The ratio flour/liquid and the way you work it will affect the end result (see examples below).

Flour also contains starch (as much as 75%!) which acts as a binding agent as well. It binds very well with water, becomes gelatinous and increases the viscosity of the batter or dough (that’s why you use flour or starch when making bechamel for example or when you want to thicken a soup). Adding flour makes a nice batter instead of a liquid mess 🙂

In terms of taste, the proteins in the flour participate in the Maillard reaction that’s explained in the video below, it’s one of the most fascinating chemical reactions! The Maillard reaction is what makes your baked goods golden and caramelized.

Let’s take some examples

When you make a pie crust, you want something crispy, it shouldn’t rise or be moist but it shouldn’t be too crumbly either.

You’re going to use very little liquid and work the dough just enough to bind all the ingredients. Once you have a smooth dough, you need to stop and let it rest in a cool environment (like a fridge) for a few hours so that the gluten can “relax”. If you try to flatten a dough you’ve just made (or handled for too long), you’ll see it will shrink back right away because the gluten makes it too elastic.

On the contrary, when you’re making bread or brioche, you want something moist and fluffy inside with some crust outside. You need to add more moisture (water, milk or eggs for example) and work the dough a lot. That’s what we call kneading: we’re going to massage and squeeze the dough until it’s incorporated a lot of air and the molecules of water and gluten have fully bound together into a soft, smooth and elastic dough. Again, it will need to rest in a cool environment.

Why can’t I just replace the flour in the recipe to make it gluten free?

Some recipes like the chocolate lava cake can be made flourless really easily. You want to make a dense cake that will not rise, won’t have a crispy crust and won’t be fluffy or elastic, meaning you don’t need gluten. In our chocolate lava cake, we replaced the flour that was in the original recipe with corn starch because you still need some kind of binding agent to hold the cake together. In this recipe, you can decide whether you want to use flour or starch according to your own preference in terms of texture and taste.

Other recipes are naturally flourless (meringue, Marocaines, chocolate mousse, pannacotta…).

However, in most cases, if you want to adapt a recipe using wheat flour into a gluten-free recipe, you’ll most likely have to use a combination of ingredients to make up for the loss of gluten and starch. Now you understand why gluten-free recipes always call for a lot of ingredients! Making a gluten-free mix is advanced chemistry…

One thing a few wheat-sensitive customers told us when we had the store was that their body wasn’t reacting badly to our pastries, they were able to fully enjoy them! We believe the reason was that we used only organic unbleached wheat flour and no preservatives or artificial flavourings. So there is hope if you’re mildly sensitive and you can make your own pastries at home, controlling everything that goes in them! (I can’t guarantee this will work for everyone though)

Why are there so many types of wheat flours?

Professional pastry Chefs often have more than one kind of flour in their kitchens depending on the type of baking they’re doing. Each one is used to make different baked goods. 
The categories below are the main types we find in Canada and the US.

Bread flour (or 00 flour) will be “stronger”, meaning it contains the most gluten (11-14% of protein) and provides more structure than the other kinds. Use it for bread and pasta for example.
For pasta, you can also use semolina or durum which is a high-protein wheat flour.

Standard All-purpose flour contains 9-11% of protein and if you have to choose one kind only, this one will do for pretty much everything!

There’s also cake flour which has an even lower protein amount (8-9%) that you can use for pie crusts and everything you want light or crumbly (scones, biscuits, pancakes…).

Whole wheat flour is made by milling the whole kernel of wheat with its germ and bran. To make white flour, only the inside kernel is milled; the germ and bran are discarded. By doing so, we lose a lot of nutrients and fibres present only in the germ and bran, that’s why whole wheat is considered more nutritious.

I generally use whole grains in my savoury dishes but in pastry it’s just not the same. You can’t make proper French pastries with whole wheat 😀
You can make good whole wheat bread but a classic baguette has to be made with white flour!


Post a comment

Your email address will not be published. Required fields are marked *