Culinary Chemistry: Gluten-Free Recipe Conversions – Strategies for Substitutions
by Jenn Oliver
When my husband and I first started cooking gluten free in our kitchen, we mainly focused on one type of meal — those that were naturally gluten free.
The naturally gluten-free foods were the easiest to cook from scratch because they required no substitutions at all — risottos, fresh fruit, vegetables, custards & puddings, stir fry, roasted potatoes, homemade “chips”, salads, fresh steamed fish, bean stews, meringues, and even a macaron attempt or two. As a beginner to the gluten-free world nearly five years ago, I was thrilled with how many foods we could make without ever having to worry about an ingredient on a package label that could be harmful to my husband’s health. As long as we cooked from entirely fresh ingredients and avoided anything that came in a package or required flour, we were fine — and what a great variety we had to choose from!
But it didn’t take long before my husband would say, “You know, I really miss pizza,” or “Wouldn’t it be nice to have a thick creamy gravy to go on mashed potatoes sometime?” It was inevitable, really, that shunning all things flour-related was bound to cause waxing nostalgia for the meals we no longer ate. While it was great to get our feet wet by starting with the easy gluten-free meals that didn’t require any substitutions or extra thought, it seemed wrong to deprive ourselves completely of other foods that we enjoyed.
I set out on a mission of sorts to figure out how to convert our favorite foods to gluten free, where I found a veritable “Wild West” frontier land when it came to recipes — myriad flour blends and formulas either in packages on grocery store shelves or listed in books, none of which explained how they came to be or why they worked, often calling for expensive and elusive ingredients. It all seemed like some esoteric recipe voodoo.
I decided instead to create my own blends, first categorizing the various alternative flours and ingredients by texture and coarseness, and then quickly realizing that while those aspects do play a role in the end product, the key factor was in fact not the texture, but the starch, protein, and fat content, as these are the things that determine most how a flour will behave in a recipe. I can’t say I get a perfect product every single time on the first try, but the turning point in my success was when I started looking into exactly what I was replacing with my gluten-free flour blends.
Sometimes it really is the gluten that needs to be emulated, such as in a bread recipe, where the developed network of gluten in conventional breads actively works to trap the air pockets made by the yeast, allowing the bread to rise. Techniques for mimicking this include adding other leavening agents to help account for the fact that some of the air will indeed escape before the bread is done, or adding binding agents to help trap the air that is formed — and maybe even a combination of both of these techniques.
Often this is why one sees gluten-free recipes that include extra eggs, or gelling agents like ground flax or chia seeds, manufactured gums, or incorporation of starches into the GF blend, such as tapioca or arrowroot. Once we understand why these ingredients exist in a gluten-free recipe, we can better judge how to make substitutions to fit our needs – for example, don’t have ground chia seeds? Maybe adding an egg in its place will do the trick. The bread fell flat a bit and was too dense? We now have options. We consider the properties of the ingredients we are using, and this information can be used as tools for determining how to logically go about changing our recipes to improve them.
Other recipes that conventionally use flour don’t actually care about the gluten at all. Take, for example, a roux, essentially made up of a flour and a fat that are cooked together and then used as a thickening agent in soups and stews, such as gumbo. In the case of roux, there’s no elasticity needed, and no air to be trapped – all we are looking for is thickening, which occurs thanks to the starch components within wheat flour. This is great news for gluten-free cooks; there are lots of starchy gluten-free ingredients at our disposal that we can use to replace conventional wheat flour!
All-purpose wheat flour contains, along with gluten, a fair amount of starch. So to create a 1:1 substitution (by weight of course), one would just need to come up with a gluten-free flour blend that is also mostly (but not all) starch. This can be done either by using flours with similar starch content to wheat flour, or by supplementing the GF blend with a pure starch (cornstarch, tapioca, arrowroot, potato, glutinous rice flour, etc.). Each type of starch differs slightly in its chemistry, but for the most part they all have gelling and viscosity properties – i.e. they help food thicken and stick together. In something like our roux example, it’s not going to matter a whole lot what kind of starches we use, because the only aspect of the starch we are calling upon in this case is its thickening power.
Obviously, for baking, things get a little more complicated, but I’m convinced the overall strategy remains the same. The first thing I ask myself when converting a recipe is, “what in conventional wheat flour is doing the work? What traits do I need to make sure I replace with my gluten-free mix?” And then we can use our knowledge about the various gluten-free ingredients available to reproduce those properties. Actually, I think once one gets a bit more comfortable with gluten-free substitutions, there is even more freedom and more possibilities for “customizing” than when working with conventional all-purpose wheat flour. This is because one has the ability to pick and choose from amongst so many great ingredients — not just for certain properties, but also for flavors. For example, I often incorporate chestnut flour, because I just love the earthy rustic qualities it lends to baked goods.
Gluten-free substitutions don’t have to involve some mysterious wizardry in order to have success. Sometimes it’s just a bit of recipe tweaking, and other times, a little knowledge about the science behind why a recipe works goes a long way.