A velna is a cane crushing mill: rollers turned first by bullocks and later by a tractor power take-off, feeding juice into a line of open iron pans over a furnace, boiled down and poured into moulds to set as gur.
The season runs from about November to February. The furnace is fed with the crushed cane itself, so the process is self-fuelling, and the smell of a working velna carries a long way.
Gur, shakkar and the softer rab are eaten through winter, given after childbirth, used in pinni and in medicine, and offered at shrines.
Sugar mills and the cooperative sugar factories took most of the cane. Punjab's cane acreage has fallen and the velna is now largely a Doaba and Kandi practice, run seasonally by families who sell direct.
It is one of the very few food processes left in Punjab that is done in the open, at village scale, and sold without a label.
The pans are a graded set and the juice is moved from the largest and coolest toward the smallest and hottest as it thickens. When it is ready is judged by eye, by a drop let fall into cold water, and by the sound of the boil. There is no thermometer on a velna anywhere in Punjab.
The whole operation is seasonal and shared. A velna serves several families in turn and the boiling runs day and night for weeks.
Gur keeps the molasses that a sugar mill takes out, which is where its colour, its minerals and its taste come from. White sugar is the same juice with that fraction removed and sold off separately as cattle feed and distillery input, so the two products are the same plant split in two directions.