In celebration of our king finding the village that was cheating him he decides to throw a celebration for the other 9 villages. In preparation for the celebration he orders 1000 barrels of the finest wine.
When the members of the uninvited village find out about the party they send an assassin to poison one of the barrels of wine. The poison takes 7 days to kill so the party guests won't realize what is happening for awhile.
However, after poisoning a random barrel the king's guard finds out and has the assassin executed. There is no time to order more wine so the king devises a genius plan to have his 10 loyal servants taste test the wine to find the poisoned barrel just in time for the party in 10 days. What is the plan that he devises so that he is left with 999 barrels of wine for the party?
Update: Added number of days until party (10)