This is the major protein in grains and is proportionally highest in wheat. Gluten is what allows the flour of yeast-raised baking to swell and lighten, but this only happens if the gluten is first encouraged to stretch by kneading. So-called 'hard wheats' have the highest gluten content, which is why they are preferred for yeast baking. Such other bread-making grains like rye have much lower gluten content and thus are often mixed with wheat flour to make breads.
Gluten can be isolated from wheat flour by thorough washing and thus is extracted and used as an incomplete vegetarian protein source in Asian and in Western vegetarian food; it needs to be eaten with pulses or legumes to provide complete protein.
Gluten intolerance (coeliac disease) is increasingly recognised as a dietary concern and gluten-free products are now more available, even in supermarkets.
Gluten is contained in all wheat and products that contain wheat, and to a lesser degree in many other grains. Buckwheat, corn, millet, oats, quinoa, rice and wild rice are gluten free. Commonly sold as seitan (Japanese), health food shops and the web offer gluten as a vegetarian meat substitute. Powdered gluten can be added to bread mixes for a lighter result.
Choose the best
For best baking results, flour must be dry and never smell musty. Use seitan and other extracted gluten products strictly as instructed.
Storage advice is the same as for the product that contains the gluten.
Hard wheats with high gluten content need a lot of kneading to ensure a good result in yeast-raised baking. Choose soft, lower gluten flour for home-made pasta, because domestic pasta rollers struggle to stretch the degree of gluten in hard wheats. Gluten-free flours make excellent cakes of all kinds as baking powder does not need gluten content to create risen lightness.
Gluten (seitan) is slightly firmer than tofu (soy protein) and is thus more like meat. Its bland taste absorbs other flavours the way tofu does, so is used very much the same way.