DB Export trucks were out in force at Gull Omahu Night'n Day on Saturday morning, but there was no beer in sight.
Instead, people scrambled to take advantage of free Brewtroleum - fuel made from a DB Export byproduct - which was dished out in the form of vouchers. The owners, Karen and Perry Laurent, said the giveaway was brilliant "with a lot of happy folks".
In June last year, after teaming up with Gull petrol stations, DB Export's Brewtroleum became the country's first commercially viable biofuel from the by-products of brewing beer.
There were television advertisements and social media posts touting, "drink DB Export and help save the world", to increase beer demand which increased the byproduct, yeast slurry, to make petrol.
Yeast slurry is usually sold off to farmers for cattle feed. It still has ethanol coming off it and during "ideas over beers" the team at DB Export dreamed up the idea of using it to power cars.