The Grapes of Wrath Stomped is an achievement in Blood and Wine expansion and is only achieved if you help united the two warring vineyards (Vermentino and Coronata). For this, you must complete the side quests in a certain order.
Go start Wine Wars: Belgaard and you'll be given two additional quests, each with 5 parts: Wine Wars: Coronata and Wine Wars: Vermentino. Make sure to loot keys and read the letters, particularly at the guarded treasure location northeast of Coronata and at the guarded treasure northeast of the Sansretour Valley signpost for Vermentino.
It doesn't matter what order you do all 10 tasks, but it is important that before you turn anything in, you do Wine Wars: The Deus in the Machina (which will pop up once you gather the second piece of evidence). With this, go the designated location far south and investigate, making sure to loot and read the Stocktaking Report. Go back to Plegmund's Bridge and turn in this evidence, which will put an end to the bickering. If you already completed all 10 tasks, you can then go with them to Belgaard Vineyard or, if you haven't, the 2 separate vineyard quests will combine into Wine Wars: Consorting. Once complete, turn it in.
Once they've happily teamed up, you'll have to do one last quest, Wine Wars: Belgaard, with 5 more separate tasks. Afterwards, they'll ask you to drop back in after 3 days and, when you do, will name a wine in your honor, netting the achievement.
- You do not need to have Wine Wars: Consorting to appear to get this as it only appears if you found the two pieces and did Wine Wars: The Deus in the Machina before completing all the tasks.
- It's important not to turn in to the clerk until you gathered the evidence. Otherwise, even if you helped both, they'll still argue while reluctantly running Belgaard together.
- the name of the quest is a reference to John Steinbeck's novel, The Grapes of Wrath.