FARMINGTON — The users and the gurus of compost were among those dropping by the two-day compost demonstration at the Sandy River Recycling Association recently.

The users went to purchase finely screened compost that was a year in the making; the gurus went to see the machine that was screening it. And the man who designed and manufactured the portable screen for his family’s company in Brooks, Jon Thomas, went to see his new machine in operation.

“It was a good turnout; people came with everything from five-gallon buckets to pickup trucks and left with finely screened compost made from food scraps and manure,” said Ron Slater, SRRA manager.

Among the compost gurus were Mark King and Will Brinton. King is with the Maine Department of Environmental Protection, is on the faculty of the Maine Compost School at High Moor Farm in Monmouth and is advising SRRA on expanding its compost operation.

Brinton is CEO of the internationally recognized Woods End Research Laboratory in Mt. Vernon that has advised everyone from students at Cape Cod Hill School to Prince Charles to the San Diego Zoo in the making of compost. He came to check out the screen.

The Mallett School picked up some compost. The food scraps from the cafeteria made up several tons of the compost. Slater gave the school four cubic yards to use in planting trees at the new school.

Picking up three truck loads for use in his community-supported market garden was Joe Hodgkins of Temple. He paid $45 for the three loads.

Those who did not make it, said Slater,  may pick it up from 7 a.m. to 3 p.m. Monday through Friday.

The basic “recipe” for making compost calls for air, water and organic matter rich in carbon and nitrogen.