The COVID-19 pandemic continues to put significant strain on Molson Coors' (TAP -0.41%) business. That's the main takeaway from the alcoholic beverage giant's latest financial update, which covers the months of April, May, and June, spanning the biggest impacts yet on bar and restaurant closings.

The sharp drop in customer traffic at these establishments pushed sales volumes down 12% compared to a 2% decline in the prior quarter, Molson Coors said.

The slump was most pronounced in Europe, where sales dove 21%. But the U.S. business also shrank by a brutal 8%. Executives estimate that on-premises sales fell to essentially zero during the period, leaving the supermarket and retailing channels to provide all of Molson Coors' revenue production.

A cooler filled with ice and bottled and canned drinks

Image source: Getty Images.

The company says sales started to pick up again as economies reopened in June, but volumes will likely remain pressured at least through the next quarter. Meanwhile, Molson Coors is working through several supply chain problems related to the dramatic shift toward at-home alcohol consumption. It is having trouble sourcing enough aluminum cans to package its products, for example.

These challenges combined to convince executives to hold off on issuing any outlook for the rest of the year. "The market remains too unpredictable to provide an updated detailed financial outlook at this time," management said in a press release.