1. Cook bacon in skillet until crisp; remove to paper towels. Reserve 1 Tbsp. drippings. Crumble the bacon when cool enough to handle.
2. Peel and slice the vegetables. Place the onion in the bowl fitted with the ultrablade knife and mix at speed 11 for 10 seconds.
3. Scrape down the sides of the bowl, add the bacon drippings and celery. Launch the P1 simmer program at 270°F for 5 minutes.
4. At the end of the program, add remaining ingredients and cook at speed 1 at 210°F for 45 minutes.
5. At the end of cooking, pulse for 10 seconds or until desired consistency is reached.