Ethanol gained the most in five weeks on speculation that natural gas pipeline shutdowns will force distillers to reduce production. Futures rose 2.1 percent, snapping the longest streak of losses since July, as TransCanada Corp. (TRP) shut three pipelines after an explosion and fire 50 kilometers (31 miles) south of Winnipeg, Manitoba. Natural gas is used to power ethanol plants. “That pipeline up in Canada is affecting things,” said Mike Blackford, a consultant at INTL FCStone in Des Moines , Iowa . “That may cause some of these plants to slow down.” Denatured ethanol for February delivery advanced 3.7 cents to settle at $1.794 a gallon on the Chicago Board of Trade. Today’s increase was biggest on a percentage basis since Dec. 19. Futures have fallen 25 percent in the past year. Gasoline for February delivery rose 0.61 cent to $2.6278 a gallon on the New York Mercantile Exchange. […]