Its off-trade sales director John Whittle said the 500ml bottle is performing strongly in independents and specialists like Majestic, but has also seen a sales increase in multiples, particularly Booths.
He attributes the sales hike to more people drinking at home and matching lager with home-cooked meals.
The 10-pack is flatter than most cases of beer and is designed to stand out on shelves teeming with competition.
Whittle said: “The idea is that this new design is sufficiently different to help project that feeling of something special that customers shopping in the specialist outlet expect.
“Our new pack offers just what’s needed – a top beer and plenty of it in a party format that’s rather more elegant than anything offered by the mass produced brands.”
This week the Czech brewery won a Supreme Court case in which the UK's most powerful court ruled it can share the Budweiser trademark with global giant AB-InBev, which produces Budweiser.
The Supreme Court rejected a request by AB-InBev to overturn a ruling made by the Court of Appeal. The Court of Appeal had said Budejovicky Budvar NP should keep the right to name its beer Budvar Budweiser.