Protesting dairy farmers say they shut down a Morrisons depot for 11 hours on Thursday night as part of a continuing protest over milk prices.
Tractors lined the road to the store's distribution centre in Bridgwater, Somerset from 1600 BST, leaving at 0300 following talks with police.
Farmers have accused the supermarket of backtracking on pledges over the price of milk used to make cheese.
Morrisons said it was disappointed at the actions of "a minority" of farmers.
The supermarket announced weeks ago it would create a new "Milk for Farmers" cheddar which would "deliver the equivalent of 10p-a-litre back to farmers", amid a row over the price of milk.
But farmers joined the protest from Somerset, Devon, Cornwall and elsewhere.
One, James Badman, said: "Unfortunately Morrisons seem to be just backtracking and not willing to go along with what everyone else is already doing."
It is the second time this week protesters have parked tractors outside the regional distribution centre, just off the M5.
Farmers for Action said hundreds of people turned up on Thursday.
Delivery lorries were backed up along the road to the centre, but Somerset farmer James Small denied "blockading" the depot.
"The tractors are parked on the side of the road so employees can get in if the need to... the protest acted at all times within the law".
A spokesman for Morrisons said: "We know that this is a difficult time for British dairy farming, but we are disappointed by the actions of a minority of dairy farmers who are attempting to disrupt the supply of food to our customers."
It added that following discussions with the National Farmers' Union, it was "introducing measures" to help farmers deal with global reduction of the farm gate price of milk.