It doesn't get more simple than bread and butter. They are the staples that can feature at every meal: Smeared thickly with jam (or avocado) at breakfast; enveloping cheese and ham, or dunked in soup at lunch; and as the opening - alongside pickles, salami, roast peppers, a green salad and tomatoes - to a decent dinner.

They are tough to do without - the ultimate double act. But so often, we rely on industrially produced bread (so handily sliced and uniform in size) and pale, easily spreadable supermarket butters, rather than the real deal.

And the thing is, if you've got proper bread and butter in front you, you don't even need cheese or ham, tomatoes or pickles. All you need is a knife, a board, and no embarrassment about going back for seconds, thirds, fourths...

If this is your thinking too, you'll appreciate Bread & Butter by baker Richard Snapes and chef Grant Harrison; it's both a cookbook, and a cultural and historical look at two of our most fundamental foods.

The problem is, "inherently we love s*** bread," says Snapes in the floury belly of his Snapery Bakery, a sourdough wholesalers in south-east London. As he shows me how to fold and rest bubbling dough in plastic tubs, he explains, we've grown incredibly used to sliced white, largely because it tastes like cake, when real bread should only be flour and water and a little salt.

The 90-100 sourdough loaves he sells a day, though, are the epitome of real. However, ask him about the age of his sourdough starter (wild yeast) and you'll be treated to a wry eye-roll. "I have a bee in my bonnet about starter stories," he says, incredulous at the bread world's penchant for putting ancient ones on a pedestal.

"It doesn't really matter, it all makes bread," he says with a laugh, before admitting that his initial starter did come via the Ukraine, thanks to fellow cookbook author Olia Hercules, who gave him some hop flours to experiment with, which turned out to be "immediately active, like rocket fuel."

We're making and baking his signature field loaf, a versatile plain loaf loaded with wheat; it was the first bake he really got the hang of as an amateur baker. "It's really nostalgic," he says, describing his childhood spent growing up in a village in Northamptonshire, surrounded by "miles of wheat". When he started making this field loaf, he realised it reminded him of something, and then it dawned: "It smells like a field of harvested wheat after it's rained."

It's a romantic story, and true, but the reality is, Snapes has been up since 4am (that's a lie-in for him, more often than not his day starts at 2am) and neither he nor Harrison get to go on bread and butter tasting trips - you'd assume they'd be dashing to the continent every chance they got - but there's no time (how could there be when you're churning out 150 kilos of butter a week?).

For Harrington, his early memories of butter feature Kerrygold at his grandparents' ("It was so yellow,") but one butter in particular changed the direction of his entire life.

A chef in restaurant kitchens like Gordon Ramsay's, he ended up at Faviken in Sweden, working for Magnus Nilsson. On day one, he tried the butter there, and "how buttery the butter was, blew my mind". So, he went and set up Ampersand Butter Culture, and now supplies fresh, cultured butter to Michelin-starred restaurants, amongst others.

Harrington and Snapes met at Druid Street Market - their stalls were side-by-side - but are still wowed by what the other produces. Snapes is practically giddy as we churn butter by hand in a small paddle churn, cheering Harrington on as the paddling agitates fermented cream from Jersey cows, until the fat in it emulsifies and splits into buttermilk and globules of yellow butter ('butter popcorn', to those in the know, and the yellowness indicates how much grass the cows ate).

While Harrington is almost as much a novice as me when it comes to turning proved dough out, ready to be slashed with razors to create a crust and give the bread room to swell in the oven.

'Why are they called 'ears'? asks Harrington gesturing towards the slashes in the bread.

"Because you can pick it up by the ears," says Snapes, hooking a freshly cooked loaf up by the crust, and grinning.

For Harrington, the whole business of bread and butter is about "trying to make the best of the basics, the stuff we eat every day." Neither of them has time for those who get jumpy about carbs and dairy. "These are essential items, they should taste the best they can, or it's doing them a disservice."

As we haul some loaves Snapes prepped earlier ("Blue Peter style,") a crackling sound fills the bakery. He explains it's the change in temperature affecting the bread that does it, but his first explanation that it's the loaves "singing" is even better.

We eat the butter on the bread, as thick as you'd spread peanut butter, or cheese. And it needs nothing else.

Bread & Butter: History, Culture, Recipes by Richard Snapes, Grant Harrington and Eve Hemingway is published by Quadrille, priced £22. Photography Patricia Niven. Available now.