Proofing is one of the most important elements of the baking process. During proofing, yeast is activated and converts glucose and carbohydrates to carbon dioxide and alcohol. The carbon dioxide makes the dough rise, while the alcohol lends flavor once it is converted to to acetic and lactic acids by the yeast. The time needed for proofing varies and is a result of mixing, first fermentation, yeast level and temperature of the proof box.

“Doughs that are too soft usually spread out rather than rise because of their inability to trap gases,” says Rich Labriola, owner, Labriola Bakeries, Alsip, Ill. Different dough formulations require varying temperature, time and humidity.

Various options exist for achieving optimal humidity in the proof box. Steam proofing, for example, uses steam to create humidity in the proofer. In a water-mist proofer, steam or electricity raises the box temperature, and then a water mist is sprayed into the air to achieve the desired humidity. Regardless of how humidity is created, having the controls to maintain proper temperature and humidity is imperative.
“Accurate humidity is crucial in many ways,” Labriola says. “Too dry a proof box and the product will ‘skin’ over, thus hindering its ability to grow in the proofer.” By contrast, if a proof box is too wet, the product can get too soft and spread, affecting its volume and final fermentation ability. “Usually when you are doing pan breads, you want a wet proof box so the dough can spread and still be supported by the pan,” Labriola says.

Bakers look to suppliers for added control
“We have control systems that allow some range of adjustment,” says Bill Terry, director, sales and marketing, Turkington APV USA, Goldsboro, N.C. “When a baker is running a particular product he can set the parameters so they are repeatable. If he wants a certain temperature for one particular product, he selects that product and those temperatures. Those humidities are already in the PLC, which transmits the information to the control devices.”

A proofer’s temperature varies depending on baker preference, product and proof box set-up. Usually the temperature ranges from 110°F to 125°F with a relative humidity of 95 percent to 98 percent. “We have our proofers set a little warmer than needed for artisan bread, but we put them in the retarder to extend the total proof time,” Labriola notes.

In recent years, advancements in proofers have been focused around the design. Proofers are becoming easier to maintain with a focus on sanitation. Many proofers contain all stainless-steel, non-corosive materials inside and have washers or rack washers that can be operated on a down day, without the need for added labor. The Henry Group offers a spiral proofer with an optimal belt washing system, which uses line water pressure through spray nozzles to clean away product debris.

Proofers also are growing more automated. “Today’s modern bakeries have all the automated controls and the PLCs,” Terry says. In the past, conveyorized and rack proofers required more manual labor, including different controllers that someone needed to set. “Now a lot of these functions have moved to the PLC and you have an operator interface that allows the operator to see what is going on,” Terry says.  “You can look at the temperature over time and the humidity, the speed and things going on inside the proof box.”
In the past, proof boxes were set up to run multiple products. Today’s bakeries are choosing higher speed lines with greater throughput, but running fewer types of products. When running multiple products in one proof box, bakers need a proofer with a lot of flexibility, which means it may not offer as high a throughput.

Manufacturers predict future proofers will feature better controls and more automated maintenance, something bakers are already requesting from their suppliers; including proofers that can predict if maintenance or lubrication will be needed soon. Eventually a proofer may even be able to automatically maintain itself.

When choosing a proofer, remember options abound and every bakery has unique needs. “There is no one particular proofer that is right for everybody,” Terry says. “A supplier has to talk with a customer to find out what products he wants to run, what his floor space requirements are and how automated he wants the proofer to be. Then, you can select the right piece of equipment for a customer.”