OXFORD – Roger Jackson has been making maple syrup on and off since he was 6, along with his father and his grandfather. It was the family’s sugar substitute during World War II. But just five years ago, his syrup-making skills were on the shelf.

Now the shelves are lined with bottles of home-made maple syrup. Jackson and his family are back in the business. And like dozens of producers across the state, they’ll open their operation Sunday to the scrutiny of public tastebuds for Maine Maple Sunday.

The event is in its 20th year. Visitors to area sugar houses can often see syrup made as well as sample the results on pancakes or ice cream.

Jackson had pretty much given up tapping trees, boiling sap and the rest until his granddaughter said the magic words: “Papa, I want you to make me some syrup.”

She must have heard about it in kindergarten, he figures. Anyway, that was the turning point.

“She got me boiling, and I started smelling the syrup, and said, ‘Oh, boy, I’ve got to get back into that.'”

He’s back, with help from his younger brother, Caldwell, his daughter, his wife and the whole family. They’re running about 600 taps on 300 trees and this year graduated to a professional evaporator. He’s hoping to produce between 70 and 100 gallons of syrup.

They might even make some money at this in a couple of years, he said.

Until then, there’s the sweet smell of the sap and the smiling faces of his customers.

Here are some of the places to be on Maple Sugar Sunday: