Salt as a yeast stabilizer
August 16, 2016
by Charlotte Atchley
Salt assists in critical formulation needs such as yeast stabilization, gluten strengthening and flavor.
Salt’s importance in the bakery is most evident in the fact that even in the simplest bread formulation — flour, yeast, water and salt — its presence makes a big difference. Though considered a micro ingredient, salt carries important functions.
“Salt has three major functional roles in baking: enhancing flavor, strengthening protein and controlling yeast fermentation,” said Marie Thomas, vice-president of Innovation, bakery ingredients, AB Mauri North America. “While standard salt levels found in baked goods only average around two percent of ingredients (on a flour weight basis), it makes a large impact on dough processing, yeast activity and finished taste profiles. On a commercial scale, salt plays an important role in extending the shelf life of products, and it impacts the dough’s rheology.”
In various bakery applications, these different functions carry more weight than in others. For example, in products relying heavily on gluten, yeast stabilization and protein strengthening rise to the top. In products where gluten isn’t as important, flavor takes center stage.
“In baked goods leavened with baking soda or baking powder, such as cookies, muffins and biscuits, salt still serves the same functional properties,” said Chef Scott Keys, manager, culinary operations, Nu-Tek Salt. “However, despite its decreased role in the functional sense, the role of salt, in this case, becomes increasingly important to the overall flavor and mouthfeel of this variety of finished goods.”
But all the same, changes in salt content will have an impact on finished products, whether in structure, texture and mouthfeel, or flavor.
In yeast-raised baked goods, salt plays an vital role in stabilizing the yeast. Yeast needs the water present in bread or cracker dough to become active and start producing carbon dioxide, the gas bubbles that cause all the expansion needed for dough to rise. Salt competes with yeast for that water.
“Salt slows down the yeast’s ability to grow and produce carbon dioxide,” said Julie Schuette, senior food technologist, Cargill. “It slows down the proofing time.” That may not seem like a desirable outcome, but when unchecked by salt, yeast can become overactive and produce carbon dioxide very quickly causing dough to expand faster and more than it should.
Without enough salt, gas bubbles form before the gluten structure of the bread has enough time to form and strengthen properly, and the gas just bursts through the fragile gluten strands. “You won’t have the nice homogenous distribution of air cells throughout the slice,” said Janice Johnson, PhD, food applications leader, Cargill Salt. “You’ll have these big gaping holes in there, which are not desirable for sandwich breads.”
From a production standpoint, overactive yeast not only results in inconsistent finished products but also unpredictable fermentation rates. Salt helps rein in that active yeast to a more controllable and predictable standard, something commercial bakers need if they are going to produce consistent loaves of bread or runs of crackers.
Even in bakeries that struggle with extreme temperature fluctuations or high humidity that could impact proofing times, salt can help regulate this production stage. “If a bakery gets really hot in the summer, bakers really appreciate being able to control their fermentation rates and times,” Ms. Schuette said.
In bread, controlling the yeast fermentation prevents the dough from becoming too sticky and hard to handle, said Siobhan Hudson, technical sales representative for Kudos Blends. This is important on a commercial scale where bread is handled by automated equipment.
While the absence of salt or not enough creates over-active yeast, tip the scale in the opposite direction and yeast can’t get its job done. “Too much salt can slow down the yeast activity, not allowing enough expansion,” said Adam Fisher, partner and COO, Oceans Flavor Foods. “The challenge is to find the right salt that does the right thing for the right application every time.”
The partnership between salt and yeast is so intertwined, that to maintain proof times, Ms. Thomas said, adjustments in salt and yeast levels must go hand-in-hand.
While this function of salt is critical in all yeast-raised products, it also plays a unique role in frozen doughs. These goods need to be able to rise after being thawed out. The yeast must lay dormant and survive the freezing process until the dough can be thawed. Only then should the yeast be activated. “As soon as you activate that yeast, it’s vulnerable to the freezing process,” Ms. Schuette said. “If you can keep it from becoming active, you ensure it will be active later when the baker thaws it out.” Cold water and a quickly dissolving salt keep the yeast dormant for the freezing process. Once the dough is thawed, that yeast will wake up, and the dough can be proofed as normal.
To ensure this process and product stability when going from frozen to oven, SaltWorks offers custom encapsulation options.