Margarine and butter prices are soaring. Here's why.

The cost of butter and margarine has skyrocketed over the last year, one of several humble kitchen staples that have surged in price amid the fiercest inflation in 40 years.

As of December margarine prices were up a whopping 44% from a year ago, according to the Consumer Price Index, while butter prices jumped 31% during the same period. The average price of butter soared to $4.81 per pound in December, up from $3.47 a year prior, according to the Federal Reserve Bank of St. Louis.