The River Cottage star labeled the festival a "plastic nightmare" after seeing venues give out plastic cups instead of reusable glasses over health and safety fears.
Revellers are given single-use plastic pint glasses to carry their drinks from venue to venue and eliminate the risk of broken glass underfoot.
Hugh tweeted: "Having a great time at the #EdinburghFestival, but it’s a #plastic nightmare, with most bars and venues insisting on plastic for all drinks (except cans).
"I get the wish to avoid broken glass, but SO MUCH PLASTIC. Anyone here found a good solution? #WarOnPlastic #edfringe2019".
Other anti-plastic campaigners at the festival backed the chef, including comedian and actor Vikki Stone, who said: "I completely agree. I took a plastic cup back to a bar to re-use, and they told me they WERE NOT ALLOWED TO. Insane."
While other festival goers told of their own enterprising ways to enjoy an eco-friendly Fringe.
Amy M tweeted: "My husband and I bought leather tankards a few years ago & take them to events - they don't break & beer stays cool."
Other attendees suggested Fringe bosses give out hard, reusable plastic cups for a deposit of a few pounds.
Festivals including Glastonbury have stopped using plastic cups at their bars, while Reading Festival gives revelers 10p for every cup or bottle that is brought to a recycling point.
An Edinburgh Festival Fringe spokeswoman said: "The Fringe Society is committed to reducing the environmental impact of the festival and has a number of initiatives in place to achieve this.
"We have worked with Creative Carbon Scotland since 2010 to provide advice and guidance on sustainability for Fringe participants and venues to limit the impact of our activities on the environment.
"Venues across the Fringe landscape have adopted a range of measures this year including the use of fully compostable plastic cups and Vegware."