So I always wondered what each flour does to the baking and I thought I would share what I now know. I got the information from a cook book Deliciously G-free by Elisabeth Hasselbeck. Everything I write is straight from the book. I recommend that you buy this book, it's very helpful and has great recipes.
Black Bean Flour:
Black bean flour works great with dense chocolate desserts because the rich taste of chocolate masks the flavor of the beans. Since beans are high in fiber, black bean flour holds moisture in chocolate cakes and brownies. I don't recommend this flour for vanilla-flavoured baked goods since the color and bean flavour will come through.
Brown Rice Flour:
I consider this the "all-purpose" flour for g-free baking. It has a mild flavour and is a great base for many recipes. Because it has a gritty, slightly granular texture, mix it with flours that are great at absorbing moisture, like black bean, coconut, and sorghum.
Coconut Flour:
This is one of my favourite flours. It's extremely high in fiber: just 2 tablespoons deliver 5 grams, a boon for celiac sufferers, who need to supplement their fiber intake. Even if you're not a fan of coconut, mixing small quantities of this golden-yellow flour with other flours improves texture of your cakes and cupcakes and helps ensure a moist crumb. Coconut flour gives my yellow cupcakes (pg 194) their lemony color and cuts the graininess of brown rice flour while keeping moisture in.
Millet Flour:
Millet flour is milled from a small grain that reminds me of tiny round popcorn kernels, but with a milder yet nutty flavour and a much lighter texture. Since some gluten-free flours don't absorb as much liquid as their glutenous counterparts, millet's drier chalky consistency and medium texture make it the perfect sponge for any baked good containing moist fruit or large amounts of heavy liquid, like my banana bread (page 213).
Potato Flour:
Like coconut flour, potato flour grabs moisture, but it contains less than half the amount of fiber found in coconut flour. It works well when combined with gritty flours like brown rice and sweet white rice to balance out the texture in cookie recipes and baked goods that contain less liquid. Use potato flour in moderation when mixing with other flours, as it burns easily.
Potato Starch:
Many g-free bakers sat that potato flour and potato starch at the same, but potato starch tends to be a lot finer in consistency and bright white in color, compared to the dull of-white of potato flour. Potato starch works well to enrich sauces and provides a crisp-on-the-outside, soft-inside texture for waffles.
Sweet Sorghum Flour:
Sorghum is grain harvested from a grass, and is America's third largest grain crop. Like gluten-full whole wheat flour, sweet sorghum flour has a dark, speckled cinnamon appearance and a course texture. It has a unique mineral profile that is high in iron (for healthy blood and heart), potassium (crucial for hydration), and phosphorus (important for growing bones and teeth). It's the perfect base for quick breads, muffins, pancakes, and biscuits.
Sweet White Rice Flour:
Sweet white rice flour reminds me of powdery white cake flour, traditionally used to create the fine crumb for which dainty white cakes are famous. I use sweet rice flour as the main flour in my brownies because, much like cake flour, it has a lighter texture and is higher in starch than brown rice flour. It also seems to magnify the flavour and mimic the texture of the melted-chocolate.
Tapioca Starch:
Tapioca starch has the lightest, finest texture of all the baking flours. It's responsible for that irrestible "crackle" on top of my brownies (page 209). It also makes the dreamy-smooth pudding filling that you'll find in recipes like my banana cream pie (page 202), and it helps to crisp the outside of my signature chocolate chip cookies (page 215).
Subsitutes for Gluten:
Gluten is a combination of two binding proteins, gliadin and glutenin. Found in wheat, rye, and barley the very ingredients to avoid on a g-free diet - these proteins are what give bread its chewy bounce and cakes and brownies their delicate, moist crumb. Without gluten, or without the major players that step in to do its work, most baked goods crumble and lack that tender, moist, or chewy texture that makes homemade treats so good. Xanthan gum and Guar gum have been pinch-hitting for gluten in baking for some time. If you've done and g-free baking up to this point, you've probably encountered them in recipe ingredient lists. But if you've not heard of them before, don't be intimidated. Here's what you need to know:
- Xanthan gum is a binder made from the fermentation of sugars isolated from corn. Traditionally it is used in salad dressings to help them pour well and prevent separation, and it is added to toothpaste and ice creams to help those products maintain their thick mousselike consistency. (If you've ever had xanthan gum clinging to your fingertips, then washed your hands, you've noticed an interesting slippery flim forming on your fingers before it melts away). In baked goods, xanthan gum increases the viscosity of the batter. Xanthan gum is sold in powder form, usually in 5-6 ounce bags. Since it's used in small amounts, one bag will be enough to supply you with great baked goods for many months to come.
- Guar gum is derived from the seed of a plant grown in India and is typically found in powder form (like xanthan gum) in health food and specialty food stores. Guar gum has eight times the thickening power of standard starches, like corn or potato, and gives more bounce to baked goods. Commercially, it's used for a thickener in hot and cold drinks, and you'll find it in your favourite summertime Popsicles.
Both xanthan and guar gum range wildly in price - from $3.50 a bag to $12 per 8 ounces, depending on where you buy it. Look for deals on the Internet, but remember that there's no need to order either one in bulk since most baked goods require only a teaspoon.
In recipes, xanthan and guar gum add the binding and moisturizing properties that are lost without the gluten from wheat, rye, and barley. In most cases you can use xanthan or guar gum interchangeably in cakes, cookies, and breakfast foods like pancakes and waffles. Using too much will create a gummy, almost rubbery baked good, and using too little will mean crumble city - that dry texture that gives g-free baked goods a bad rap. As a rule of thumb, start with 1 teaspoon xanthan or guar gum when converting your favourite traditional cookie or cake recipe.
Just like the g-free flours, xanthan gum and guar gum store well in a dark, cool place. Xanthan gum has a long shelf life, up to two years, and guar gum up to eighteen months, so once you stock your baking shelf, you'll have a go-to ingredient any time you're craving brownies or chocolate chip cookies warm from the oven. I usually mark the date of purchase somewhere on the container, to eliminate guesswork later on.
