I crafted the drink ahead of time, clicked on the three items for the quest then went to my inventory and consumed the drink I had crafted - got the achievement the second I did that.

jle30303 wrote: »

you haved to drink the relevant drink (1) while the quest is active (i.e. after completing the meal and before going back to Breda), and (2) within the Betnikh feasting area.

I actually finished the quest and ate/drank the quest items, then consumed the provisioning food while still in the area and it worked for me.

Just to be clear, “drinking” the spiced ale as part of the quest does not count. You or someone else must obtain the festival provisioning recipe and craft the item to be consumed.