Baking is a form of applied chemistry, though most bakers never need to learn this because they work with a small number of well-understood ingredients. Life is much more complicated for bakers who work without crucial ingredients such as eggs, either because of food allergies or as part of a vegan lifestyle. Successful vegan bakers must understand the role played by specialized ingredients such as xanthan gum to achieve the best possible baked goods.
The Problem of Eggs
Milk and butter are readily replaced by vegan substitutes, but eggs are more problematic because of the multiple roles they play in baking. Emulsifiers in the egg yolks help other ingredients mix and stay mixed, while adding richness, flavor and fat. The proteins in egg whites firm up when baked, and help give the finished goods their structure. Egg proteins also trap air in the dough or batter, helping it rise. No single ingredient or product can replicate all of those characteristics, but xanthan gum is one of the most useful.
Xanthan gum is produced by microscopic bacteria. They're fed on a high-sugar growth medium derived from corn or wheat, much as yeast is commercially produced on a molasses base. The bacteria construct a protective coating for themselves, which is purified into xanthan gum. The gum has a strong thickening effect, and is often used in low-fat salad dressings and other food products to improve their texture. The gum is sold to consumers as a powder, which can be mixed into either liquids or oils for baking and cooking purposes.
Xanthan Gum in Baking
Xanthan gum is valuable to vegan bakers in several ways. For one, it bonds freely with both oils and water-based liquids and helps keep them emulsified. It also helps replace the eggs' contribution to the structure of your baked goods, holding other ingredients together in much the same way as the egg proteins. This in turn helps trap expanding gases within the dough or batter, contributing to the lightness and tenderness of the finished product. The effect is even stronger when xanthan gum is combined with starch-based thickeners or guar gum, which have many similar properties.
A Few Tips
Xanthan gum has only a mild benefit as an emulsifier, but it works well in conjunction with other emulsifiers such as lecithin. Liquid lecithin or lecithin granules can be found at most health food stores, and will help your ingredients combine more readily for improved texture. Xanthan gum is also crucial to gluten-free baking, where its elasticity helps replace the gluten proteins and make lighter, fluffier breads. In quantity xanthan gum can cause intestinal distress for some diners, but the small amounts used in home baking aren't a problem for most people.
- On Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
- Bob's Red Mill: Guar Gum vs. Xanthan Gum
- Kids with Food Allergies: Cooking and Baking Without Egg Ingredients
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