The Burton-Upon-Trent brewer has "changed the process, not the recipe" of its 50cl bottle in order to better reflect the taste and aroma of the cask ale version, according to brewing director Richard Westwood.
The new red label design will also be rolled out to cans and cask hand pulls, but they will both remain at 4.5%abv.
Westwood told OLN: "We didn't want to produce a new beer. We used the same raw materials and tweaked the process to produce a beer that retains all of Pedigree's characteristics.
"It's a better match to the cask version."
The new bottles will start appearing on shelves over the next couple of weeks. Marston's have pledged to absorb costs so there will be no price rises stemming from the launch and new look.