Alaska Air just carried paying passengers on two flights using a mix of jet fuel and a biofuel made from corn. The flights took place on Tuesday.
The airline said the flights were the first ever to use fuel based on alcohol made from fermented corn.
Both flights departed from Seattle. One landed in San Francisco and the other completed a longer trip to Washington D.C.
The biofuel was developed by Colorado-based Gevo and used a similar process to that used to make traditional ethanol.
Gevo separates the nutritional protein for animal feed and then converts the starch to isobutanol, a kind of alcohol that is then converted to jet fuel.
The new isobutanol used in jet fuel was only approved by US regulators in March.
The first commercial flight powered by a mixture of conventional fuel and biofuel took place in 2011.
Biofuels are expensive and oil prices have been falling which has led airlines away from such fuels.
Depending on the type, biofuel can cost between a third more and three times more than conventional fuel, according to RDC Aviation Economics.
Gevo said its new fuel could address those concerns because it can be derived from other, cheaper inputs such as sugar or waste wood.
“Gevo’s jet fuel product is an important step forward, in that it has the potential to be scalable and cost effective, without sacrificing performance,” said Joseph Sprague, Alaska Airlines’ senior vice president.
The airline estimated the 20% biofuel blend it used for the two flights reduced greenhouse gas emissions by 50%.
It’s not clear if Alaska Air will continue with the biofuel blend on future flights.