Don't get hung up on the Dew quite yet... It's very possible/likely if there is a goal it'll only be to get the building to level 5. All buildings got level 6 as a part of the Dew "upgrade" and the new tavern probably has level 6 because of that.
But by all means continue to collect Dew(at least from Ivy Hut) and make the special beams and blocks but don't use them to upgrade anything until S8 advertises a goal requiring it... The Dew is just too hard to come by to upgrade the "wrong" building and it would take years to Max out the new Beams/Blocks.