Climate change is to blame for shrinking bread loaves, a baker in Canada has told customers.

Graham Beck, who owns Little Stream Bakery in Ontario, said a prairie drought had impacted the supply of ingredients required for his loaves, resulting in much smaller loaves as they aren’t rising as they should.

In an online post, Mr Beck wrote that his bakery purchases spelt wheat and rye from Ontario farmers. However, their Kamut—a heritage grain also known as khorasan wheat—comes from the prairies.

“Kamut needs to come from the prairies as it needs a dryer climate of the typical prairies weather. But not extremely dry! This extreme drought has led to a supply issue and currently the only Kamut we could locate is of lower protein and therefore rises considerably less,” he wrote.

“You may notice our Kamut breads are significantly smaller and that is why we put them in more compact loaf pans.”

Kamut International, which owns the Kamut trademark, told Mr Beck that crops in the US had also been hit hard by the harsh conditions. Although he found a new supplier, the grain wasn’t up to scratch.

“It was kind of like a lump and, sure enough, the bread didn’t rise much,” he told CBC News.

“And we had to work with it because that’s all we could get.

“We weren’t happy about it, but we had two choices: make it the way we could with what we had or not make it.”

With supply issues caused by the pandemic compounding the impacts of climate change and extreme weather, Mr Beck expressed concern for the future of small businesses.

“We have to really be looking at the big picture and food security,” he said.

“And what we can do to look more locally, have alternative supplies, [and] be working to support farmers.”