‘The process starts with soaking the dried soy beans. We wash and rehydrate them in water, then we grind them up,’ David points to what, to all intents and purposes, is a gigantic coffee bean grinder, ‘so that we can cook them.’ The ‘coffee’ which spurts out, splattering the steel basin, is a shade of creamy mashed potato. From there it’s transferred to three cauldron-like cookers and heated up to 100°C.

The process isn’t pretty. As it cooks, the purée bubbles over, lending a mad scientist’s lab look to this part of the factory. Cleaning these at the end of the day can’t be an enviable task – yet the smell emitting from the cauldrons is curiously comforting, like roast nuts or malted milk. ‘Once we have it at 100°C, we can separate the soy milk from the fibre,’ says David. Though Ron, the ‘hippy’ who founded the business, did this bit by hand, the Knibbs automated it when they took over. ‘Those bits where it doesn’t matter whether a machine or a person is in control we have automated, where possible. This machine presses out the fibre, and we give that to local farmers for animal feed. It’s the milk we’re interested in,’ he continues, moving toward the heart of the factory where a team of blue-hairnetted people stand over steel vats wielding long wooden spoons.

‘This is what I call the art form end,’ explains David, peering carefully into each of the vats. Inside is the junket: the soy milk which, thanks to the addition of a coagulant, is slowly separating into curds and whey. The coagulant David uses is nigari, but bigger tofu makers invariably use calcium sulphate. ‘That makes it taste chalky, and while nigari (a natural extract of sea salt which David sources from the Dead Sea) doesn’t get as a good a yield, it makes for a better flavour.’ Meanwhile, the art of stirring this mix – getting the right curd formation and spotting the precise point at which to drain the whey off – is the difference between firm tofu with bite and texture, and the jelly-like slop which historically gave the curd such a bad name.

‘This here is getting quite nice.’ Dave seizes a spoon and pokes gently at a vat’s custardy contents. ‘You’re looking for a scrambled egg texture. A fairly solid curd should form after twelve minutes – but you have to watch it.’ Too soon, and it’s soggy; too late, and you’ve the soy bean equivalent of an in-flight cooked breakfast on a budget flight. ‘Now we can press out the whey,’ – a laborious processes involving one man, a colander and a lot of heavy lifting to transfer the whey from the vat to a drainage system. ‘We are working with the Bio Renewal Centre of York at the moment to see if there’s a way of concentrating the whey to make it a worthwhile ingredient. At the moment we are just throwing it away, and it is such a shame as it still has protein content,’ laments David, whose sense of environmental responsibility remains admirably unshaken by the pressure he’s under. Next year he’ll start recycling water and looking into alternatives to plastic packaging. Right now, his priority is his bulging order book.

The next step is one even the most intermittent of tofu eaters will have heard of: the press, responsible for transforming loose curds into a block that’s recognisably tofu. For centuries this took the form of heavy bricks or wood blocks, placed on top of the muslin-wrapped curds for hours; these days even smaller producers like Tofoo have resorted to a machine. The muslin cloth remains however: there are some things technology can’t better, and the muslin allows the whey to seep out without affecting the curds’ taste or texture. After cooling down – an optional phase, but one David firmly believes helps the tofu hold together – the finished product is hand-cut into portion sizes and packed up in thermaform. ‘Most tofu you see in the supermarket comes in a water bath, which can be a bit off putting. Ours is firm – there’s no need to press it further – and ready to use.’

Unlike Ron, the business founder, the Knibbs are not vegetarians or vegans– nor do they want to confine their sales to non-meat eaters. ‘We want everyone to enjoy it.’ Meat-free Mondays and Veganuary, for example, have done wonders for their outreach amongst flexitarians. ‘The biggest barrier to selling tofu is people understanding what to do with it,’ David continues. They’ve worked hard to overcome this, slotting tip cards into their packs and encouraging customers to share their recipes, but Tofoo is also swimming with the tide. Our appetite for Southeast Asian cuisine and for meat alternatives is growing. Our awareness of environmental and ethical incentives to curb our meat intake is, slowly, rising. The secret to Tofoo’s success is not clever marketing or social media, but the quality of their product: and that, in a soy bean shell, boils down to how it is made.

Photography by Joseph Fox.