Bakers embarking on gluten-free processing may feel like Christopher Columbus stepping off onto Hispaniola. It’s a whole new world out there and one that doesn’t automatically reward knowledge of conventional bakery engineering. But there are enough common factors in equipment selection and performance to get you started.

The essential processing aspects for gluten-free lines apply as well to most bakery needs, according to Stephen Marquardt, sales director of North and South America, Zeppelin Systems USA, Odessa, FL. Equipment must handle doughs and their inclusions gently. It must be designed to avoid cross-contamination and fit the sanitation needs of emerging food safety regulations. It must control temperature and time parameters accurately, and it must be configured for quick changeovers.

Click for a slideshow about gluten-free processing.

But it’s the doughs that make things different.

“What’s most important are the ingredients and the formulation,” said Ken Hagedorn, vice-president, sales, and partner, Naegele, Inc., Sussex, NJ, who recently helped teach a course about gluten-free baked foods to a group of QSR operators. “These determine the equipment choice.”

Nature of the dough

Of course, the chief problem with processing these doughs is that they have no gluten. To be labeled “gluten free,” foods can contain no more than 20 ppm (20 mg per kg) gluten, according to regulations announced by the Food and Drug Administration in August 2013. The CODEX standard is the same. Even if present at 20 ppm (the equivalent of a shotglass of vermouth added to a tanker load of gin), that’s not enough to form the unique wheat protein network responsible for the desirable light, airy texture of baked foods.

Guar and xanthan, often the choice to replace gluten’s structuring function, become very gummy and sticky when wet. They can gum up slicer blades during packaging of finished products. And from an ingredient handling standpoint, the dry materials are often lighter and starchier in texture than conventional wheat flour. Many gluten-free flours absorb more water than regular flours. Some flours exhibit reduced water retention, although typical gluten-free doughs are generally moist and sticky. They form gas cells slowly, and the elasticity of the dough system is decreased.

“The various grain flours, starches, gums and different protein sources impact the rheology of the dough,” said Cesar Zelaya, bakery technology manager, Handtmann, Inc., Lake Forest, IL. “That makes each gluten-free dough unique in terms of how it needs to be properly handled for proofing or baking.”

And now, those structuring ingredients are changing again. “The latest trend is to get rid of gums (guar and xanthan) that have become so high-priced because of competition from the oil drilling industry,” observed Franco Fusari, sales managing director, Minipan s.r.l., Massa Lombarda, Italy.

Bakery equipment designers and engineers have their work cut out for themselves. “We start by analyzing and learning the new product and have developed some solutions dedicated solely to gluten-free foods,” Mr. Fusari explained. “These accommodate the various enzyme and starch ingredients now being used, which make ­every application different.”

Still, it’s the lack of a gluten network that poses the main difficulty. “Despite a similar appearance in finished products to gluten-containing goods, all gluten-free doughs lack structure and don’t have the tension of conventional doughs,” Mr. Fusari said.

Some bakery products are more difficult to produce than others. Mr. Marquardt observed that frozen doughs and items requiring the sponge-and-dough process don’t readily go gluten-free.

Divide and conquer

Dough handling presents the most challenges in this category. “Proofing and baking will be the same as a conventional product,” Mr. Hagedorn said. “It’s the front of the line that’s different. With batter-like doughs, an extrusion or depositing system is necessary. Some doughs are like English muffin doughs and even wetter than ciabatta dough. But stiffer, more dough-like mixtures can be managed like regular bread dough.”

Another factor is the broad diversity of gluten-free baked foods with widely differing processing equipment needs. “In the conventional world, companies tend to specialize in product types,” Mr. Fusari observed, “but in the gluten-free world, all the major players have a broad range of products, savory to sweet.” And that complicates equipment specs. “Each line has to be different,” he said.

Consider the demands of dividing. During depositing, gluten-free doughs tend to entrain air and stick to equipment surfaces, explained John McIsaac, vice-­president, strategic business development, Reiser, Canton, MA. “To automate the process, we need to consider how to minimize and disperse air in the dough and get the divided portion directly into the pan it is going to be baked in,” he said.

Extrusion is generally the choice for portioning and depositing such doughs. This technology can accommodate both loose and stiff doughs, although customizing may be required.

Reiser’s Vemag dividers address the problem of sticky, fluid doughs with a double-screw design for moving the mass gently through the machine. “Our new ‘zero’ double-screw disperses entrained air,” Mr. McIsaac explained. “[The results are] no large holes in the bread and a nice, even crumb.” The company offers attachments that divide bread and roll doughs directly into pans.

The Handtmann VF 600 Bakery Series divider employs a vane cell system to manage widely varying viscosities without incorporating air or damaging dough structure. The machine moves small portions through the system for continuous output. “The vane cell geometry provides a very short dwell time, greatly reduced friction and minimal manipulation of the dough,” Mr. Zelaya said. The system can be customized for semi- to fully automatic operation and benefits both loose, high-absorption and stiff, low-water doughs.

The overly dense nature of some gluten-free baked items creates an interesting handling puzzle that Handtmann engineers are able to manage with simple adjustments of the divider settings. “We achieve high volume and quality standards with gluten-free products,” Mr. Zelaya reported.

One big recent installation for Minipan was a gluten-free pizza line in Spain doing 6,000 crusts per hour. “The company claims to be the biggest such operation in the world,” Mr. Fusari said. “In that line, the challenge was to feed the dough without using a pump between the mixer and the divider.” Instead, engineers developed a special dough transfer hopper.

Although gluten-free foods have been marketed for many years, consumers have new expectations of this category that affect the type of equipment used to produce these goods. They want their gluten-free foods to not only taste like regular styles but look like them, too. What’s more, demand now comes from more than just the celiac and wheat intolerant communities.

Makeup and handling

“This is the third time that the gluten-free game has changed for us,” Mr. Fusari said. Italy leads the world in gluten-free foods, and the company started designing and building equipment for this category in the mid-1990s. At first, the need was supplying bread acceptable for celiac diets, and then food companies moved into making products close in appearance and taste to conventional products. “This allowed a celiac to invite friends to dinner and serve gluten-free breads that wouldn’t be recognized on sight as gluten-free,” he said.

“Now, people are eating gluten-free for health and wellness reasons even if they are not celiacs,” Mr. Fusari said. “The challenge to us as a bakery machinery company is to help our customers make products that are attractive to the eye and ­appealing in taste.”

Minipan’s SYR3 and COMBY3 lines are customized to ­gluten-free processing needs. “We have also recently launched sheeting lines for gluten-free,” Mr. Fusari added.

Gemini Bakery Equipment Co. has delivered gluten-free makeup lines for bagels, pan bread and pan rolls. “We have learned that gluten-free doughs differ from bakery to bakery substantially,” said Mark Rosenberg, CEO of Gemini Bakery Equipment Co./KB Systems, Philadelphia. “We normally need to do in-house testing of a client’s ­formula before determining our best solution.

“The ability to bake gluten-free product is quite similar from one client to another,” he added. “We have had good success with both our double rack and quad sized rack ovens for the full range of gluten-free products.”

Considering the limitations of gluten-free doughs, Liam Burns, vice-president and managing director of Fritsch USA, Inc., Cranbury, NJ, indicated that the company’s baking lines can be made suitable for these products. “The only time we have to pass is when a product and its production presuppose a certain minimum elasticity in the dough, as with the three-­dimensional coiling process,” he observed.

Rolling and dusting

“[Gluten-free] dough tends to be very sticky and can pose issues for some equipment,” said Jon Thompson, national sales director, Rheon USA, Irvine, CA. The company applies its Stress Free technology in combination with encrusting and co-extrusion systems to manage the needs of gluten-free dough.

“With our WN066 and KN550 Encrusting systems, bakers can produce a wide range of gluten-free products from loaf breads, hot dog buns and hamburger buns to dinner rolls, sandwich rolls and bagels,” he continued. “Cookies can also be produced from a simple divided puck to up-scale cookies with fillings and unique shapes such as filled twists and open-top styles.” Breakfast bar shapes can also be made.

Rademaker equipment with low-stress feeding systems fits the makeup needs of this category, according to Eric  Riggle, vice-president, Rademaker USA, Hudson, OH. “Gluten-free doughs behave better with lower stress,” he said.

For flow control, these lines monitor the dough as it goes into and out of the reduction rollers. “You can’t stretch these doughs or put them under too much tension,” Mr. Riggle said. “Given any stress, they will release water. The less pressure and stress you put on these doughs, the more accurate and consistent the finished product.

“Another thing, gluten-free dough doesn’t like to sit around,” he added. “It has to be processed quickly or else it becomes sticky and difficult to handle.”

For Moline Machinery, the key to success is managing stress during sheeting. “It is critical to start with a good sheet,” said David Moline, sales and marketing manager, Moline Machinery LLC, Duluth, MN. “Tearing is a challenge. For this reason, we employ automatic gap control and automatic spread control for the rollers on the Libra line to ensure the sheet is as relaxed as possible. We also automatically control the conveyor speeds.”

These lines employ sensors to monitor the condition of the dough and to enable automatic adjustments on the fly. “You really can’t do that with manual operations short of putting an operator at each reduction station,” Mr. Moline said. “You have to let the equipment be your eyes.”

If doughs are so sticky and prone to tearing, why not use dusting flour to smooth the operation? “With regular doughs that are sticky, you can use wheat flour to dust it so it moves through makeup equipment,” Mr. Hagedorn noted. “But with gluten-free products, you have to use gluten-free flours. They are much more expensive than wheat flour, and they are more difficult to reclaim and are basically non-reusable. The other choice is oil.”

Mr. Fusari described another approach to dusting that employs starch rather than flour. “These starches can be very dry and very different from each other,” he observed. “So the starch sprinklers have to be custom designed for each kind.”

Appearance is king, but making products too uniform isn’t always best. “Some gluten-free producers want all the products to be identical; others want the look of handmade artisan products,” Mr. Moline said.

Fortunately, there are good choices for achieving such effects. “But you have to allow this in the automation,” Mr. Moline said. Such systems include a computer-timed guillotine that subtly alters individual piece weights but yields uniform total weight for multiple-piece packages. Rotary cutting methods, applied to flatbreads, can also foster a handmade appearance.

A tip about packaging: Consider the advantages of gas-flush techniques with nitrogen or carbon dioxide. “Our Repak packaging machines offer modified atmosphere packaging to extend shelf life,” Mr. McIsaac said. This method lets bakers market gluten-free items at ambient temperatures in the bread aisle, rather than putting them in refrigerator or freezer cases.

Learning from experience

Several equipment manufacturers offered advice to bakers considering this category.

“Think ahead,” Mr. McIsaac urged. Products in this category seem to change more quickly than standard baked foods. “We have seen producers buy machinery that can only be used on one product type. When their product mix changes, they need new equipment.” Instead, he recommended seeking systems with modular design that eases modification.

And then there’s the testing needed to optimize equipment selection and configuration. “To ensure success, we advise customers to ‘slow down, test first,’ ” Mr. Riggle said. Rademaker operates a test bakery in Culemborg, The Netherlands, where the company is headquartered. “We’ve tested every gluten-free job at this facility, and we learned something new each time,” Mr. Riggle said. He described working last year on one of the biggest gluten-free lines to be installed in the US. “After running tests of the equipment, the line’s configuration came out completely different,” he reported.

Equipment choice boils down to what works best for the product. “I recommend bakers approach it in a similar way to all other products,” said Jim Kline, president, The EnSol Group, Erwinna, PA. Functional specs for gluten-free doughs should describe their viscosity, extensibility, density, absorption, temperatures and so forth, just as any other baked food.

“If you don’t find what you are looking for, don’t hesitate to look outside of the box,” Mr. Kline advised. “With enough persistence, you will find a supplier who will not flinch when they read your requirements.”