ST. LOUIS — New innovations are rolling out from a test bakery opened last summer by Panera Bread Co in New Haven, Conn. The company said it is using the facility to test new products while reimagining Panera classic items, including bread with new grains and croissants with updated fillings and flavors. The company also is using the facility to experiment with staffing models, with a goal to enhance the bakery side of the company’s business.

“Panera began with bread,” said Tom Gumpel, the company’s head baker. “It’s our passion, soul and expertise. Our test bakery is an example of our continued focus on our identity as bakers, as we push ourselves to keep learning how best to lay out, staff and operate our bakeries.”

Panera is studying the test location to understand how updated products and staffing models may affect its nearly 1,800 bakery-cafes.

Several innovations are planned to roll out across the bakery-cafe chain this year. A new sprouted grain bread offering, currently testing at the New Haven bakery, will be available in all Panera locations as a bagel flat beginning in May.

“We are one of the first restaurant chains in our industry to offer sprouted grain bread products to our customers,” Mr. Gumpel said. “This grain wasn’t available to purchase at scale when we started testing, but through relationships with our millers we’ve been able to grow the supply. Sprouted grains are a good source of fiber and rich in taste. This is another nutritious whole grain that Panera is making accessible to its customers in popular bagel form. It’s an incredible step forward for our bakeries.”

The sprouted grain bread launch follows the recent introduction of a lineup of flatbread sandwiches. In test for more than a year, the flatbread is Panera’s take on traditional Indian “naan” with fillings inspired by the global travels of Mr. Gumpel and Panera’s head chef, Dan Kish. The three flatbread varieties include Mediterranean chicken, Thai chicken and Southwestern chicken.