Well, let's not call them Vikings for a moment since that word in old norse merely means raiders or pirates. Norsemen established a farflung trading empire across northern europe and the Black sea that would have brought them into contact with trade goods, possibly through secondary traders, from not only the Islamic world, but, through the Western end of the Silk Road, with goods from China and India. 8th century textiles have been recovered from norse burials and, of course, they had access to resources like amber and narwhal and walrus ivory, luxury goods sought after throughout the known world. It's quite likely coffee would have been at least known to them. It's a misconception to think of norse people as primarily sailing warriors. They were mostly agrarian people. Eldest sons inherited everything so their brothers could either herd pigs for them or go raiding. That's really why they went to Iceland and Greenland, to not be a thrall with no future but an owner of your own sheepcroft