There's more than one way to achieve the taste and aroma of freshly baked yeast-raised products. That option may be a boon to companies facing clean air regulatory deadlines later this year.

Adding yeast to a bread or cake is the traditional way, of course. The other method is to add a yeast flavor.

Natural and artificial yeast flavors can be added to formulations containing yeast to intensify the flavor, or they can be used with other leavening systems to contribute a yeast flavor. The deep meaty base notes in the flavor give it an intense "traditional bread flavor," according to officials at Seafla Inc., Milford, Ohio.

Applications for the flavor include bread, pizza dough, dinner rolls, cakes, donuts and other baked goods. The flavor is available in liquid or dry form so it can be added to liquid formulations or dry mixes.

"This flavor survives the heat of baking," says Jeff Higgins, general manager at Seafla. "We have not had a situation where it doesn't work." Usage levels range from 0.2% to 1% depending upon the application.

In light of yeast's connection to ethanol and the approaching regulatory deadline, some companies may wish to switch from yeast to yeast flavor even if it means reformulating. The Clean Air Act Amendment of 1990 requires that bakers in certain areas of the U.S. install control technologies for ethanol and have them running by May 31.

Ethanol is formed during yeast fermentation and is released into the air when products are baked. Although it's not a pollutant per se, ethanol is considered a volatile organic compound that could contribute to air pollution. After ethanol is emitted from ovens, a single oxygen molecule could break off from each alcohol molecule and combine with oxygen gas to become ozone. Ozone could react with other compounds in the air to form smog.

This is a concern for companies located in 33 ozone non-attainment areas identified under the amendment, explains Anne Giesecke, vice president of environmental activities for the American Bakers Assoc. (ABA). Companies with plants in these zones - depending on the area and the amount of ethanol the plant emits - will have to install ethanol emissions control equipment. ABA member groups in the affected areas are currently negotiating with their states to reach an agreement on acceptable rules.

The economics of installing control equipment may prove daunting for some plants. It could cost $500,000 to install control equipment at a single plant, and $125,000 to maintain the equipment for a year, according to Giesecke. Catalytic oxidation systems can be used for ethanol control. Other systems - such as heat exchangers and biofiltration systems - may be applicable, but may not have been used for this purpose before.

The critical factor in economic viability is not the overall size of the plant but the magnitude of the emissions. "If the cost is $2,000 to $5,000 per ton to control ethanol, the plant is still economically viable. If the cost is $10,000 to $14,000 per ton, the economic viability of the plant is challenged," Giesecke remarks.

Companies in the baking business are currently evaluating their options. Among them are the types of equipment to install. Another approach, though radical, might be to reformulate - to switch from yeast to a chemical leavening system and add yeast flavor.