Also Known As Flour-Free Ferment or Water Preferment System
What is Water Brew?
Water brew, or flour-free ferment, consists of water, yeast, 3.5-4.5% sugar (based on flour weight), brew buffer (usually containing calcium carbonate), but no flour. It varies mainly by the ratio of water to yeast, which falls within the range of 4/1 to 20/1 ratio. Sugar is added to supply adequate food for the yeast for proper fermentation.
Brew buffers can prevent the pH of brew from dropping below 4.0. The pH of brew without buffer added will drop below 4.0 over time, causing yeast to be unstable and losing its gassing power. Different concentration of buffer added in the brew affects the brew’s pH value. A usage level of buffer depends on the percent of calcium carbonate used in the buffer, and usually a usage level of 0.1-0.25% (Baker’s percent based on the total flour weight of the dough) should be adequate. The acidity conditions must be maintained within an optimal acidity range for a quicker and efficient yeast metabolism. The pH of water brew should be around 4.2-4.3 and TTA should be around 10-12. Salt is sometimes used to help slow down the rate of fermentation and improve the fermentation tolerance for handling.
In the baking industry, water brew usually ferments for 60-90 minutes in a tank with a set temperature at 27°C (80°F). After the fermentation is completed, the water brew is cooled down to between 3 °C (38 °F). The cooled brew can be stored in the holding tank for as long as 8 hours (as long as pH is >4.0) before it is pumped through to each mix. Sanitation procedures by water rinsing are necessary between brews, and complete system CIP (clean-in-place) must be done at least once a week. To understand why a water brew is less advantageous than a flour brew, read our eHandbook on Dough Systems.