US butter consumption officially hit a 40-year high in 2012 – hardly anyone eats margarine anymore.

But the amount of butter stored in refrigerated warehouses across the US is 42% lower this summer than last, according to the USDA (see graph). Not only did US cows produce less milk than expected this year, but the fat content of that milk was lower than usual, reports Bloomberg. That lack of inputs for making butter or cheese is pushing prices to new highs.

“Consumers believe that butter is a simpler product that feels more natural,” Mike Flaherty, vice president of Unilever, told the Wall Street Journal, “without understanding that it’s an indulgence made from animal fats.”

They will now.

Posted in: Infographic of the day