Bay of Plenty's popular boutique flavoured milk is set to add another flavour to its range with the introduction of Fresh Double Caramel Milk tomorrow.

Lewis Road Creamery has teamed up with ex-MasterChef NZ contestant and social media star, Chelsea Winter, to create a rich golden caramel and butterscotch blend the creators say tastes like a "Werther's Original in a bottle".

Lewis Road Creamery's new caramel flavoured milk will be on shelves tomorrow. Photos: supplied.

Lewis Road founder Peter Cullinane told Stuff the fresh double caramel milk is "authentic and nostalgic," inspired by a recipe Chelsea whipped up with their sea salt crystal premium butter.

"Chelsea made this amazing salted caramel slice and when we tried it we knew we wanted to get her on board," says Peter.

Lewis Road founder Peter Cullinane with Chelsea Winter.

Chelsea, whose book Everyday Delicious was the top selling cookbook in NZ last year, reckons the outcome is "insanely good".

"The double dose of caramel sees the deep roasted, golden caramel - with a hint of burnt sugar - combine beautifully with the sweet notes of silky butterscotch with its old-fashioned toffee flavours.

"This is the first time I have partnered with a producer to develop a product with my name on it, so it's pretty exciting to say the least. I can't wait for people to try it."

The new milk hits shelves across New Zealand tomorrow. Lewis Road added vanilla and coffee flavours to their line-up in September last year on the back of their hugely successful chocolate milk collaboration with Whittaker's.

Lewis Road first started producing (butter) out of a small shipping container in Lewis Road, Otakiri in the Bay of Plenty. The company's head office is now based in Auckland.

-Additional reporting Stuff.