What is Gluten? 
Gluten is a protein most notably found in wheat, but also present in a number of other common grains. It permits the flexibility of wheat flour as a baking material. Gluten's elasticity allows the cells that form in bread, and keep baked goods from crumbling. The elasticity of gluten increases when it is worked and decreases if it is permitted to rest.
Where is it present? 
Gluten is present in the following grains: wheat (including spelt and triticale), barley, and rye (including triticale) and almost any foods made therefrom; although oats are not themselves dangerous they are (certainly in the USA) contaminated to some degree with wheat and must be, at best, a suspect ingredient. Gluten may be present in many unexpected places. Fermented, undistilled alcoholic beverages made from these grains do contain gluten, as may such seemingly innocuous products as cold cuts, soy sauce, or hard candies. Additionally, many ingredients that are commonly found in processed foods, such as modified food starch, can be made from wheat and therefore contain gluten.
Another place you will find gluten, though not obvious, is in the production of many foods that do not contain wheat or substances in their ingredients. One common example of this are foods that do not contain gluten in their recipe, but the conveyor belts where the food is processed is dusted with flour to prevent sticking. Many "energy bars" fit this description.
There is no other way to know if this is the case by reading the label; you must call the vendor to be sure.
Why Gluten Free? 
This diet is necessary for those with gluten sensitivity, gluten intolerance and auto-immune diseases like Celiac Disease. A gluten-free diet can be useful for those suffering from an allergy to one or more of the grains (mainly wheat, barley and rye) this diet excludes. There are over 190 medical conditions that have been linked to gluten sensitivity and gluten intolerance, Celiac Disease being one of them. Celiac Disease is often still undiagnosed. Some people find that a gluten-free diet is beneficial for children with autism. It should be noted, however, that there is no evidence for an autism-gluten link. A distinction is important, because wheat and gluten are high quality food sources, not to be rejected on the basis of unfounded speculation.
It is important to note that Celiac Disease is NOT itself an allergy, but an auto-immune disorder - the body rejects its own digestive proteins used to process gluten and produces antibodies against them. In essence, the body is fighting itself, in the presence of gluten, and doing damage to the small intestine in the process. Celiac Disease becomes a two-fold issue due to the damage done to the villi in the small intestine creating a nutrient malabsorption problem that is not reversible.
How can gluten be avoided? 
Careful and constant reading of ingredients is necessary to purchase truly gluten free foods. If flour (which means "wheat flour" unless otherwise specified), starch (including "modified food starch", "food starch"), malt, or any grain containing gluten is present, do not purchase the food. Unfortunately for the person with gluten sensitivity or gluten intolerance, it may be necessary to also investigate every step of the handling of the products, due to widespread wheat contamination of certain foods by way of shared equipment, containers, and processing rooms. Cross contamination is a big issue that many do not think about when it comes to storing, handling and preparing food. Finally the utensils, equipment, and surfaces for cooking and eating must be free of accumulations containing gluten, especially ones which have been hardened on by heat, especially in toasters and bakeware.
A gluten-free diet can only be achieved by complete removal of all gluten from your foods, medicines, and any cosmetic products which will accidentally enter the GI tract (in practice, probably all of them); reducing the amount will not be a sufficient treatment. Be aware that gluten can be hidden in many processed foods and products you may normally use.
Cooking gluten-free 
To cook appetizing gluten-free meals, it’s a good idea to be aware of what function the flour is performing in your recipe before you attempt to replace it. Wheat flour can perform multiple functions: thickening, binding, adding flavour, changing texture, and absorbing moisture. No alternative to wheat flour can do all these things in the same way as wheat flour. The most difficult behaviour to replicate is gluten's binding ability.
For this reason it is commonly advised that you mix several flours or starches when substituting for wheat. Different mixtures are suggested: no one mixture is ideal in all cases, and experimentation and customization are advised.
Many, if not all, gluten-free products do not have preservatives, so it is important that they be kept frozen or used soon after purchase. Do not store cooked gluten-free breads, cakes or confections for days at a time, or they will rapidly degrade and mold. Foods containing a significant proportion of potato starch, a common ingredient in gluten-free breads, are particularly susceptible to spoilage.
You must also be aware of the presence of gluten on the surfaces and utensils you use. Flour gets in the air and can't be cleaned. So avoid cooking one thing that is non-gluten free and gluten free in the same area when using flour. Also make sure you thoroughly clean all surfaces and utensils you use for both. Remember, you can never be too careful when it comes to your health.
Other useful starches and ingredients 
Anything containing natural oils can become rancid at room temperature. Refrigerate flours in airtight packaging.
Amaranth flour 
Amaranth flour The yield of grain amaranth is comparable to rice or maize. It was a staple food of the Aztecs, and was used as an integral part of Aztec religious ceremonies. Amaranth is a complete protein.
Chia seeds produce a gel-like substance when moistened that can assist when baking raised doughs. They also function as an egg replacement in baked goods. Ground chia seed can make the end product softer and more pliable.
Cornstarch is ideal for thickening, but does not have a pleasant flavour. Too much corn starch in a liquid sauce will give a jelly-like consistency. In baking, corn starch often gives a more pleasant texture, but can give a very hard, dense consistency.
Flaxseed meal produces a gel-like substance when moistened that can assist when baking raised doughs.
Millet flour 
Millet flour Millet flours are also known as Bajari, Rotla, Bhakri, Rotti. Millets, like sorghum, are predominantly starchy. The protein content is comparable to that of wheat and maize.
Potato starch 
Potato starch is a light starch that will rise with egg as the leavening agent. Allows lighter baked goods. Use is limited by the short shelf life of products made using this starch. This includes Sweet Potato Starch.
Potato flour 
Potato flour is a pleasant thickener for gravies and can also be used in baked goods. Some bread recipes also use mashed potato flakes!
Rice flour 
Rice flour is close to wheat flour in behaviour, taste, absorption, and thickening. However, it lacks any binding ability whatsoever, and works best when combined with other flours and starches in baked goods; delicate baked goods may fail if attempted with rice flour alone.
Sweet rice and white rice flour is finer than brown rice flour, although mills are now producing fine brown rice flours for the gluten-free market. Choose the finest grind possible for gluten-free baking; coarser grinds are slightly gritty.
Brown rice flour is a whole grain flour containing higher protein than the white rice flours, and imparts a pleasant heft to baked goods. Sweet white rice flour from a Chinese or Asian grocery is as fine and powdery as cornstarch, and behaves similarly in baked goods. Sweet rice flour can be used as a thickener in gravies. Brown rice flour also makes a good roux for cheese sauces, gumbos, or brown sauces.
Teff flour 
Teff flour Teff is an important food grain in Ethiopia and Eritrea, where it is used to make injera, and less so in India and Australia. It is now raised in the U.S., in Idaho in particular, with experimental plots in Kansas. In addition to people from traditional teff-consuming countries, customers include those on gluten-restricted diets.
Xanthan Gum 
A strong binding agent that is used to replace the "stretchy" quality inherent in gluten, xanthan gum is often added to gluten-free flour blends to promote an improved texture. Use sparingly in bread, cake and cookie recipes. Xanthan gum is the fermentation product of the bacteria Xanthomonas campestris.
Celiacs who cannot tolerate Xanthan gum, due to corn allergy or trehalose intolerance, must find other alternatives.
Other binders and gums 
Xanthan gum is the most popular binding agent, but others can be used too. These include soy lecithin, guar gum, carageenan, agar, carob (locust bean) gum, gum Arabic/acacia, fenugreek gum, tara gum, konjac gum, tragacanth gum, slippery elm powder, and even gelatin and pectin. Methyl Cellulose (MC) and Hydroxypropyl Methyl Cellulose(HPMC) are commonly found in processed and package goods. These agents are often used in combination with each other.
Tapioca starch 
Tapioca starch is a thickening agent often used in Chinese foods and gum candies. This starch is derived from cassava (aka manioc) roots; it is the same tapioca as in tapioca pearls, or tapioca pudding. Best used in combination with other gluten-free flours.
Chickpea Flour 
Flour made from chickpeas, a popular alternative to gluten flours. This flour is commonly used in Indian cooking and can often be found in Indian or Asian grocery stores, sometimes labelled "besan". It has an unpleasant taste when raw but has a good approximation of wheat flour's texture when cooked. Unfortunately, some may find that it promotes flatulence.
Sorghum Flour 
Sorghum flour (also known as sweet sorghum or jowar) makes an excellent wheat flour substitute in quick-leavened baked goods such as muffins or banana bread. It is ground from the small, millet-like grains of the sorghum plant (used to make sorghum syrup). Sweet white sorghum flour is a pale pinkish-brown in color and has a pleasant, faintly sweet and grassy taste. It is best combined with a gluten-free starch such as cornstarch or tapioca and creates a fine crumb, good texture.
Skim Milk Powder 
Gluten-free bread recipes often contain skim milk powder. It adds protein and also has beneficial effects on the end product. The casein in milk makes it a good emulsifier, and it makes for a finer crumb and better consistency. People who are allergic to dairy can try substituting soy milk powder, but the results will not be as good.
Soya flour 
Soya flour is also often added to gluten-free bread recipes to add protein.
When cooking gluten free, it is simplest to look for dishes that require the least customization. A pasta dish may only require the substitution of a rice pasta, for instance. Soups may only require a substitution for thickening (rice flour, cornstarch, or potatoes also thicken soup). Gravies and sauces can be made using arrowroot starch or sweet rice flour instead of wheat flour. Recipes calling for bread crumbs may be translated into gluten-free by using leftover gluten-free breads and crackers, and even baked items, processed into crumbs. Cooked rice or potatoes may also be substituted in many recipes calling for bread crumbs.
Sandwiches can be made with corn tortillas (grilled tuna melts, Mexican-style quesadillas, turkey and cheese, refried beans) -- though the ingredients label of commercial tortillas should be checked, as some commercial firms include wheat flour in apparently "corn" tortillas -- and also with salad leaf wraps (Boston and Romaine lettuce wrapped around filling such as egg salad, tuna, turkey, ham and Swiss, etc.), and moistened rice paper wraps.
Cakes, cookies and brownies can be made with a mix of alternative flours; including nut meal. Nut meal/flours can lower the carbohydrate content in a recipe, and up the protein that is often lacking in alternative starches and gluten-free flours. Other higher protein gluten-free flours include quinoa, buckwheat, soy, and amaranth.
Cookies depend more on the physical properties of sugar than on the characteristics of gluten. Substitute any gluten-free flour or blend for wheat flour on a cup-for-cup basis, but refrigerate the dough at least two hours before baking.
Cakes also depend heavily on sugar. Add starches and possibly some guar gum until you find an effective balance.
Pies require a gluten-free crust, and possibly a new thickening agent for the filling. Use packaged gluten-free cookies to create a crumb crust.
Flatbreads such as pancakes are relatively easy to produce with the right starches and gums. Loaves are more difficult, as they need some strong, elastic gel-like behavior for the air bubbles. Xanthan gum produces an acceptable loaf, if the gum is tolerated. If Xanthan gum cannot be tolerated, try gelatin, chia seeds/meal, and/or flaxseed meal in combination with gluten-free starches and flours.
Grocery Shopping 
Avoid these ingredients:
- Bulgur is wheat that's been cracked and steamed. (Note: A good substitute for bulgur, in dishes such as tabouleh, is cooked quinoa.)
- Couscous are actually tiny round pasta spheres, and outside of Africa, couscous is almost always made from wheat flour. (Again, a good substitute is cooked quinoa, or cooked millet.)
- Modified Food Starch
- May be made from cornstarch OR wheat starch. Look for products which specify "corn starch" instead.
- Spelt and Kamut/QK-77
- These are species of wheat. (Other names include spelta, Polish wheat, einkorn, and small spelt.)
- This is a grain cross-bred from wheat and rye.
Use these ingredients with caution:
- Buckwheat is completely unrelated to wheat, and contains no gluten. However, buckwheat flour is reportedly often contaminated with wheat. To avoid wheat in your buckwheat, one alternative is to buy only whole-grain buckwheat, and check it before using the same way you would check your raw beans for a stone. Buckwheat grains are small and triangular, and a wheat grain will stand out like a sore thumb. Another way is to use only buckwheat flour that has been tested for gluten. Bob's Red Mill no longer has gluten free buckwheat flour.
- Oats are biologically unrelated to wheat, and do not contain wheat gluten. People with a simple wheat intolerance may have no trouble with uncontaminated oats, unless they have a separate allergy to oats. However, some people with celiac disease also report sensitivity to oats. There's an ongoing controversy over whether or not people with celiac disease can or should eat oats. See celiac.com for a summary of some of the research. Note that commercial oats may be contaminated with wheat; some people think this risk is higher for oats because their grains resemble wheat grains in size and shape, some people think the risk of oat contamination is the same as for any other gluten-free flour. It comes down to an individual decision. Oat flour is not a key ingredient in gluten-free baking, but rolled oats are a nutritious, delicious, versatile, and easily available food.
Check the label on these ingredients:
- Baking powder
- Some baking powders, especially in the United Kingdom, use wheat flour or starch as a carrier for the reactive ingredients. Check the label for a baking powder that uses cornstarch.
- Amy's Kitchen produces gluten-free soup in cans. Amy's tests every batch of gluten free products to 20ppm to ensure that they are Gluten Free.
- Campbell's Soups are not gluten-free; wheat is used as a thickener.
- Pacific and Imagine soups produce many gluten-free broths and soups packaged in cartons.
- Progresso soups label foods that contain the top allergens such as wheat, milk, eggs, soy, etc.; some are gluten-free. Always read ingredient labels. Pearled barley is barley, and is not gluten-free.
- Thai Kitchen produces soup in cans and rice noodle/broth packages; many are gluten-free, always check labels.
Gluten Free Yellowpages: Collaborative Database of Gluten Free Products and Services: http://www.TheCeliacSite.com
Gluten-free baking mixes are available. Some of the more widely recognised are:
- Refer to your local Coeliac Society
- North America
- Arrowhead Mills
- Authentic Foods
- Bob's Red Mill
- Breads from Anna
- Cause You're Special
- Cravings Place
- El Peto
- Gifts of Nature
- Gluten-Free Pantry
- King Arthur
- Laurel's Sweet Treats
- Miss Robens
- The Really Great Food Company
- Sylvan Border Farm