Place the chopped bacon in the Instant Pot and set it to the "Soup" setting. Add the chopped onion, carrot, turnip, and celery, and cook with the lid off for about five minutes, until the bacon starts to render. Add the chicken stock, thyme, and salt, and secure the lid, allowing the Soup function to run.
When the Soup function has finished, release the pressure naturally. Remove the lid and add the vinegar and tarragon leaves.
Serve immediately, or freeze in pint mason jars for later consumption.