Use russet potatoes: Russets — the potato we reach for most often for baked and mashed potatoes — are ideal for this soup. They hold up to hours of cooking, while providing plenty of starch to make the soup ultra-creamy.
Skip the cream and use canned milk: Nothing against heavy cream, but for a soup that cooks for hours in the slow cooker without separating, evaporated milk is the best milk for the job. You can add it at the beginning of cooking without any fuss.
Thicken with flour just before serving: You may find the soup to your liking without any additional thickening or mashing. Once the potatoes are tender, though, you can adjust the texture in two ways: First, you can take a potato masher to the soup and make it a little bit smoother. Second, you can thicken the soup by making a quick slurry with some of the soup’s cooking liquid and flour in a small bowl.
Serving and storing easy slow cooker potato soup: Classic potato soup is often served with a generous flurry of grated cheddar cheese and some crisp bacon.