A food-processing mistake turned into a free gift for cooks in Burlington this morning. The Sterzing Food Company, which has operated in the city since the 1930s, got a shipment of potatoes that managers said wouldn’t do for the firm’s old-style potato chips. They unloaded them and discovered the potatoes hadn’t been stored at the correct temperatures, and though they weren’t spoiled they wouldn’t do for making chips, as when cooked they’d all turn brown. Cathy Merritt, who works at the plant and was one of the few workers still there in the afternoon after the giveaway, says the company decided to just give away ten tons of fresh potatoes. They took the crates outside on the loading dock and people came down and got them, and took them away by 9:30 A.M. Merritt says local folks were familiar with the company because of a similar incident once before.Fifteen years ago on Christmas Eve day there was a similar situation, potatoes that couldn’t be made into chips even though they were perfectly good for other uses — so the company put out the word, people heard, and they came. The potatoes, specially grown in North Dakota for chip-making, develop too high a sugar content if they’re not stored properly, and the sugar causes the chips to turn a dark color when they’re fried.