Alfred Frederick Bird, who designed the factory, was the son of an inventor who had solved a domestic problem and built a national business on it. The factory architect was a firm called Hamblins. The buildings went up across fifteen acres - sixty thousand square metres - of red brick, blue brick, and steel-framed loading bays. When the Bird company moved its production to Banbury in 1964, the site lost its purpose. By the late 1980s it was the kind of post-industrial wreck that Birmingham had a great deal of: too big to demolish, too compromised to convert, slowly leaking value back into the ground. Bennie Gray bought it. His son Lucan Gray took over and ran the project until June 2017. A City Grant of £800,000 unlocked £1.6 million of private investment for the first phase - 100,000 square feet of buildings rebuilt as 145 units for artists, designers, and communicators. Glenn Howells Architects, a Birmingham firm, did the design work. The first phase created around 300 jobs.

The first phase of the project, completed in the mid-1990s, included one of the most theatrical decisions in modern British adaptive reuse. The factory's main loading bay was flooded. Where lorries had once pulled in to be packed with custard powder, there was now a shallow lake, with two hundred studio workshops looking down on it from the upper floors. On the ground floor surrounding the water are meeting rooms, dance studios, holistic therapy rooms, a cafe, a record shop and clothes shop, an exhibition gallery, and a 220-seat theatre with stages for musicians, DJs, and rappers. An iron dragon - enormous, riveted, faintly menacing - clings to the rear elevation of the building from the outside. It became the most photographed object in Digbeth. Phase two, completed in 2002 and now called Gibb Square, added about a hundred more studio offices, plus galleries, restaurants, and shops set around a central pool with fountains. The pool drains for dance music events.

Tawny Gray, no relation to Bennie or Lucan, built a forty-foot sculpture of the Green Man and installed it overlooking Gibb Street. It is made of vegetation grown into stone, a face composed of climbing plants and lichen and exposed mineral, the kind of work that takes its time. The Green Man is a figure from English folklore - the foliate head carved into cathedral roof bosses across the medieval country, a survival from pre-Christian woodland religion absorbed into church decoration. Putting one in a Birmingham creative quarter is a quiet act of cultural archaeology: this part of England has always built up its working myths from whatever is at hand, and the Custard Factory's myths are made from custard, code, and bracken. Toin Adams's later work, the Deluge, was installed in the restored Devonshire House building when it reopened as Zellig in May 2010 - a £9.6-million project supported by Advantage West Midlands, providing a hundred more office and workspace units in a Grade-II-listed shell.

Some of the names that have rented space in the Custard Factory over the years: the Gadget Show. Ocean Colour Scene. ASOS, before it became one of the country's largest online retailers. Codemasters, the video-game publisher. Rare, the games studio. Maverick Television. North One Television. Fused Magazine. Punch Records. The cartoonist Alex Hughes. Huel, the meal-replacement-shake company. Across the road from the Custard Factory is Birmingham Coach Station, the National Express hub that has dispatched cheap long-distance buses across Britain since 1929. Three-quarters of a mile north is the Birmingham Institute of Art and Design, the country's largest university art and design centre outside London. The whole quarter feeds on a circuit of training, production, distribution, and pubs - the same circuit Birmingham has always run on, just rerouted through software companies instead of brass-foundries.

Phase three has not formally finished. The Custard Factory now plays host to workspaces for some 400 small businesses, almost all of them in tech, digital, or creative fields. The complex also includes bars, restaurants, an arcade, the Mockingbird Cinema, a hair salon, a gallery, and a multi-purpose event space called the Old Library. Across Digbeth around it, the BBC is moving its regional operations into the former Typhoo Tea factory, Steven Knight's Digbeth Loc Studios is filming Peaky Blinders and MasterChef and This Town, and the West Midlands Metro is being extended down to the coach station. The Sunday Times rated Digbeth the coolest neighbourhood in Britain in 2018. The point is not that the survey is right - those surveys are mostly about journalists making themselves feel current - but that the area that produced egg-free custard for a hundred years has reinvented itself as the place that produces British screen drama for the next hundred. The yellow powder is still on supermarket shelves, made in Banbury. The factory it came from is now where people make television.