Petainer, KHS Japan and Mitsubishi Chemical have developed a 10L 'DLC' keg specifically designed for the Japanese market, and that supports the legislative trends aimed at reducing packaging weight limits.
The smaller size, ideal for craft beer ranges, complements the existing petainer range of 15L, 20L and 30L kegs, which are now also available in the market.
Sales of craft beer in Japan have continued to increase in recent years, despite the country's archaic regulations.
These stipulate that brews made with exotic ingredients have to be advertised as cheaper happoshu drinks because they often don't meet the 67% malt threshold required for a beverage to be called beer.
The finance ministry has pledged to change the rules, and is expected to expand the list of ingredients that can be used in beer later this year.
Microbrew momentum
Promises of a regulatory overhaul and growing consumer interest in craft ales have also led to several of the country's mainstream beer brands entering the market.
In 2016, Kirin took a 25% stake in Brooklyn Brewery, while its subsidiary Spring Valley Brewery has been creating its own microbrews since 2014.
Mitsubishi already uses the DLC keg for some of its existing product ranges, including those used by brands such as Kirin.
Commenting on the collaboration, Chris McEwan, global business development director at Petainer, said: "The partnership between Mitsubishi, KHS Japan and Petainer brings together best of breed expertise and technologies to create a much needed, cost-effective and sustainable packaging solution for Japan's beer market."
The three companies say single-use PET kegs are increasingly being used as a more economical and efficient alternative to traditional steel kegs and glass bottles by brewers around the world.
They added: "They are recyclable, cutting out costly return logistics and washing processes. In addition to significant cost of ownership and sustainability benefits, the kegs provide excellent product protection."