The texture and flavor of standard bread is the target of gluten-avoiders. Obtaining these taste and texture is as essential for free-from products as it is for any other type of bread. To achieve this, using yeast is necessary.
Yeasts are single-celled fungi that convert carbohydrates into carbon dioxide and alcohols during fermentation, the process that transforms dough. These microorganisms allow dough to grow and form the bubbles that will give the finished product its airy texture.
For thousands of years, yeasts have been used in baking and producing alcoholic beverages like beer and wine, as consumers love the taste specific to fermented products in baked goods.
Specialists from Lallemand Inc. explained that all types of baker’s yeast can be used for gluten-free products as in standard bread – fresh cream yeast, fresh compressed yeast or instant dried yeast. All of these yeasts have specific properties and the manufacturer has to choose the best match to for its baking requirements. For example, dried yeast needs a hydration step before it can be used in dough preparation. “As with all bakery products, the amount of yeast used is determined by the dough recipe and the process used. However, in free-from products, the quantity of yeast is usually greater than that necessary for standard bread products”, according to Mike Chell from Lalemand.
What does yeast do?
During the fermentation process, yeast eats sugar (carbohydrate) to produce carbon dioxide gas, fermentation and flavor components. Yeast may produce many secondary metabolites such as ketones, higher alcohols, organic acids, aldehydes and esters. Some of these, alcohols for example, escape during baking.
These stages apply to gluten-free products: the yeast still requires a carbohydrate source, which is obtained from glucose/dextrose or sugar. Producers have refined manufacturing methods, but all of these will include a proofing stage for the yeast to become active.
More than yeast
Production processes differ for the two end product categories of standard bread and gluten-free bread. Starches or flours transform into gelatin during baking to provide bread structure and texture. However, the basic components of gluten-free bread recipes are a gluten-free starch source, like tapioca, potato, rice or maize. In this case, stabilizing and gelling agents can be used as alternatives to balance the lack of gluten. Hydrocolloids such as xanthan gum, guar gum, HPMC (hydroxypropyl methylcellulose, a natural multifunctional carbohydrate polymer used as gelling agent), cellulose and egg albumen can all be used as stabilizing agents. In this case, hydrocolloids will provide the viscoelastic and gas-retaining properties found in wheat flour dough and functional proteins such as egg albumin will contribute to stabilizing the structure.
Aside from these ingredients, producing the perfect bread always starts with good flour and yeast.