Back in 2005 — before climate change took on a sense of urgency — Florian Pfahler launched a sandwich concept in Chicago with what was then a groundbreaking approach to sustainability.

Hannah’s Bretzel, a concept named for his first daughter, offers European-style sandwiches on freshly baked whole-grain “bretzel” bread, or pretzel baguettes, using premium, organic ingredients. But he also built the brand with the smallest environmental footprint possible — following sustainability trends seen in Europe, where Pfahler was raised.

For example, Hannah’s units were opened only in buildings operating 100% on solar and wind power (in partnership with an energy provider). All packaging and food waste is composted. Deliveries are made with an electric Mini Cooper. The chain was a founding member of Chicago’s Green Restaurant Co-op, to help other concepts on their sustainability journey.

But the pandemic took a toll on Hannah’s Bretzel, which had grown to seven units by 2019. When Chicago workers were forced to stay home, the breakfast-and-lunch concept saw its audience disappear.

Now two Hannah’s Bretzel locations remain open, and a third may re-open soon as workers come back to the office, said Tatiana Boucher, the chain’s brand manager.

The challenge now is finding workers for the restaurants, as it is for most restaurants across the city, she said. “We have interviews and lovely people who come through. Sometimes they show up and sometimes they just don’t.”

Still, Hannah’s Bretzel remains committed to sharing the message that sustainability can be written into a brand’s DNA. Each restaurant has a different design — with a very German emphasis on natural woods and living room-style seating — but the sustainability story is literally on every wall.

Perhaps most noticeable, is the scent of bread baking, with the bretzels — both full-sized and the bun-like “wecken” version for smaller appetites — made in house in full view of diners.

Here’s a tour of Hannah’s Bretzel in Chicago.

Lisa Jennings at [email protected]

Follow her on Twitter: @livetodineout