Production of beer and soda at the affected breweries stopped early on Wednesday, during the busiest time of the year for beer consumption in Norway. It was unsure how long it would last.
"The talks in the brewery sector have collapsed," trade union officer Oystein Gaare told Reuters. "We are on strike."
He said representatives of the brewery union NNN demanded to be included in decisions about hiring extra labor, but the employers' group NBL disagreed. He said the issue was particularly important after the EU expansion from May 1.
"We want to keep our jobs," he said. "We want real influence in how and how long labor is hired in."
He said workers feared that breweries in Norway, a high-cost country, would hire in cheap labor from eastern European countries, hurting Norwegian workers.
Norway's grocery stores are largely being depleted of eggs, butter, cheese and dry goods by a transport strike that will not end until supplies of infant products such as diapers and breast milk substitute go empty and the government enforces arbitrations.
