James White Drinks, maker of organic beetroot juices under the Beet It brand, grew the crop to cut import costs and boost its local credentials.
Some 200 tonnes of organic variety Pablo have been planted by Cambridge supplier Greens of Soham. The variety is said to have particularly high sugar levels and disease resistance.
"Bringing in beetroot juice from the Continent seemed mad," said MD Lawrence Mallinson. "East Anglia is the sugar beet capital of Europe and beetroots are a perfect crop for our local farmers."
Mallinson said sales of the juice soared after a study in August showed nitrates in beetroot juice could improve sporting stamina and boost oxygen usage efficiency.
Beet It is sold in Holland & Barrett, Sainsbury's, Morrisons and Waitrose (rsp: £2.59 for 75cl).