It began as a hobby over lockdown. The sourdough starter was a gift from his watchful neighbour, Marge. Before that, David had no interest in baking. He’d always been perfectly content with his shop bought pan. But soon he found himself setting four-a.m. alarms, getting up to feed the culture with the attentiveness of a new father. He liked that the starter needed him. A living being under the same roof. He could talk to it, like you might a dog or a houseplant. The starter was pallid and frothy, like cottage cheese that had got a little too excited. Its smell: acerbic, eye-watering if he leaned in too close. Soon David found he was making more bread than he could eat. He gave fresh loaves to neighbours and visited soup kitchens and shelters with his surplus goods. The more he fed the starter, the greedier it got. He couldn’t say exactly when it happened, but soon he was up four or five times a night, sleepwalking to the kitchen to feed his growing charge. …