The sourdough loaf has become synonymous with gentrified high streets, healthy eating and smashed avocado, as they take pride of place in bakery windows across the UK.

But despite the seemingly unstoppable rise in popularity, conventional toasters may be struggling to keep up as they are too small to accommodate them.

Artisan loaves, baked at home or in trendy bakeries, are often wider, longer and thicker than the standard white sliced supermarket offering.

And, according to consumer watchdog Which?, this makes them too big to get into the standard British toaster.

The company reviewed a sample of 78 toasters and found the average slot is 5.78 inches wide and 5.10 inches high, with a variety of depths. 

Slices of sourdough can measure up to 8.8 inches wide and therefore the only way to fit them in is by cutting the slice in half. 

Sourdough toast aficionados will also be aware of the extra time and effort it can take to make when the slice isn’t cut in half, as one end typically juts out of the toaster and must be flipped. 

"This isn’t the end of the world, but it means you can sometimes end up with a pale white border around the edge of your toast where it hasn’t had any heat," Which? said.

White-sliced bread sales were down 12 per cent in the five years to 2017, according to Mintel, and although sales of pre-packed bread were set to grow six per cent last year its artisan rivals were rising even quicker. 

According to Mintel’s 2020 UK bread market report, speciality bread and rolls were expected to have a double digit growth of 11 per cent, taking the market value to £1.1 billion. 

Opportunity for bakers

Karen Dear, the director of operations for the Craft Bakers Association, said toast is a "quintessentially British food" and remains as popular as ever. 

But she added: "It’s a shame if there aren’t more toasters that can fit the larger artisan loaves." 

Alex Waugh, the director of the UK Flour Millers’ Association, said bakers could consider making small loaves, which would eradicate the need for flipping or cutting the slice. 

"There might be an opportunity also for bakers to make sourdough loaves, or artisan loaves, less wide so they can fit in," he told The Telegraph. 

"And I think that’s likely to come along because not everyone wants a huge loaf all the time."  

He added that grilling your toast in the oven could also be an easier option. 

Lisa Barber, the Home Products and Service Editor for Which?, said: “Whether you prefer sourdough or sliced white, there’s nothing quite like hot buttered toast.

"But our research has found that many toasters are the wrong size and shape to squeeze your favourite slices of bread into.

"We found that most toasters are designed for smaller slices of bread, so anything taller or wider might struggle to fit into the slot.

"If you’re a bit of a toast perfectionist, there are a handful of toasters that will meet your baked goods needs, whether that be for an artisan bread slice or a bagel."

Changing tastes

Specialist toasters can handle wider slices and have settings for crumpets, bagels and other non-conformist teatime treats, but range from £20 to more than £100, Which? found.

The KitchenAid Design Collection toaster, for example, comes with one long slot rather than the typical two, allowing for easy cooking of artisan loaves, while the Rangemaster toaster has two slots wide enough to fit in thicker, doorstop style slices.

The research by Which? comes amid the rising popularity of artisan baked goods, Mr Waugh said.

"What people are looking for is more variety, and sourdough is part of that. In the bakery sector as a whole you’re seeing people moving away from a standard to more variety, different flavours,” he said.

He added that although sourdough’s airy texture is not to everyone’s tastes, "people are looking for that choice and individuality".