Stocking your kitchen for low-carb baking requires an investment of money and time. You’ll get the best results by using a combination of flours.
Nut flours are the basic ingredients of most low-carb baking. They are fairly high in fat, so don’t go overboard with these. You can create them on your own using whole nuts and a food processor, but it’s easy to cross the line between nut flour and nut butters. I especially like to make pecan flour for pancakes and waffles.
The following flours are available commercially:
• Almond flour produces heavy, dense baked goods due to the high fat content. Unrefined almond flour, also called almond meal, has skins and has a mottled appearance, which lend more of an earthy flavor to baked goods. Trader Joe’s produces a great Almond Meal. Bob’s Red Mill produces a finer, refined almond flour which is fluffy and fairly light textured. Almond flour can go rancid in high temperatures, so if you live in a warm climate, store it in the fridge. The carb content varies, but it’s between 3 and 4 net carbs per 1/4 cup.
• Coconut flour is dried, ground up coconut meat that has been defatted. It will impart a definite coconut flavor to your recipe. It tends to be dry, and is good in combination with other nut flours to produce a dryer “crumb”. You’ll need to increase the liquid in your recipe when using coconut flour. It has 8 net carbs per 1/4 cup.
• Peanut flour is a fairly new development in the west. Indian cooks use this to thicken curries and add flavor. It will dry out a recipe, so you may need to add some extra liquid. It has about 3 net carbs per 1/4 cup.
Flaxmeal is much less expensive than nut flours – around $1.25/lb. Flax will absorb water and swell to twice its size, so adding water to flaxmeal will produce a fairly thick gel after a few minutes. You can use this to your advantage to produce focaccia bread and pizza dough. It will go rancid in time, so it’s better to buy whole flaxseed and grind it yourself. Golden flaxmeal is 0 net carbs; dark brown flaxmeal is a bit higher.
Oat fiber is the husk of an oat, and is all fiber. It will absorb up to 7x its weight in water, so when you use it in a recipe you need to add an extra egg. (Adding extra water will not work – your recipe will turn into a runny mess.) In recipes, you can substitute 1/4 to 1/2 the amount of wheat flour with oat fiber. It pairs well with almond flour for breads. Best of all, it’s carb zero.
While not a flour, glucomannan (also called konyaku or konjac) can refine the crumb on baked goods made with nut flours. It is a fiber that provides a lot of viscosity, and a little goes a long way.
One note of caution about using fibers like glucomannan and oat fiber: too much fiber intake, especially if you're not used to it, can cause gastric problems, so don't overdo it.