Sorghum Press

Sweet sorghum is a tall grass whose stalks hold a sugary sap, much like sugar cane. A sorghum press is the machine that gets that sap out. Cut stalks are fed between heavy rollers that squeeze them flat, the juice runs off into a vessel below, and the crushed fibre comes out the far side. What the press makes is not yet a sweetener: the juice is thin and watery, and a separate pan and fire boil most of the water away to leave syrup. The press is the half of the job everything else waits on.

Two things decide how much syrup a season yields. The first is the day the cane is cut. Sugar in the stalk climbs to a peak and then falls away, and growers judge that peak with a Brix meter, a handheld instrument that reads the sugar content of a drop of juice. The second is speed. Juice begins losing sugar and fermenting within hours of leaving the rollers, so pressing and boiling happen on the same day, and the mill sits close to both the crop and the fire. Stalks are stripped and topped before they reach the mill, and a good one takes 45 to 50 kilograms of juice from every 100 kilograms of clean stalk (45 to 50 lb per 100 lb); older roller mills often recover less than half of what the stalk holds.

The press runs a few weeks a year and stands idle for the rest, which shapes what owning one costs. It pairs with a settling vessel, an evaporator pan and its fire, and stock or a compost heap to take the spent fibre, called bagasse, which comes out wet and bulky all at once. Eight to ten parts of juice boil down to one part of syrup, so the fire behind the press burns far more fuel than the finished jars suggest. The rollers are the hazard: they pull in whatever is fed to them, hands included. A mill washed down as soon as a run ends, greased through the season and stored dry will last decades; steel left wet through the idle months is what fails at the start of the next.