It's getting cold enough here in OK to start thinking of Backburner Soup again.
Backburner Soup is soup that is set on a low back burner and kept simmering night and day, using a stock pot that holds at least 6-8 quarts. Any less and the soup dries out too fast.
It does require some tending to keep the fluid levels up because if it gets too dry, the soup burns.
There are certain ingredients that don't go into a Backburner Soup for reasons I once felt I didn't have to state. Cabbage, Brussels sprouts, cabbage, broccoli, asparagus - these don't go into a Backburner Soup because they are strong flavored and the flavor goes off after a couple of days. Spinach, mustard greens, kale, radish greens, seaweed, collards, any other greens - they get slimy and sometimes get very strong. Beans - unless you are vigilant about fluids, and have a thick broth that supports the weight of beans, beans will fall to the bottom of the pot and burn. Burnt beans will ruin the flavor of the soup. Pasta, rice, and most grains are not good ideas, either, as they disintegrate and make the soup grainy. Mushrooms tend to get rubbery and nasty after a day of simmering. Fish and most seafood don't hold up well to long term cooking either, getting really strong and often rubbery. Beef, chicken, buffalo, venison, rabbit, duck, goose, bear, elk, squirrel, possum, ostrich, pigeon, ham, pork, turkey, Cornish Game Hens, pheasant...these should be used sparingly, and the longer you intend to keep your soup going, the less you should use.
This doesn't mean you shouldn't use the meat as part of the stock you make, just that shreds of the meat tend to break down and make for a stringy, sometimes unpleasantly mushy, soup.
To make a great Backburner Soup - sauté any combination of onions, garlic, finely chopped carrots, celery, and bell pepper in safflower or olive oil until they are limp, translucent, fragrant. When my garden has been productive, I use all of them.
Remove these from the pot for now and brown your meat (poultry, pig, cow, ostrich, buffalo, venison, bear are the best for long, long cooking - use less than a pound of meat total, and use boneless meat) in the remaining fragrant oil and mushrooms if you want them.
Remove the mushrooms and set aside. The mushrooms can be used as garnish on the first bowls of soup from the backburner Soup, or added to other dishes.
I like using chicken feet, they give a depth of flavor to stock and broth that is greater than using a chicken carcass and it costs about the same.
Return the mire poix (the sautéed vegetables) to the pot with the meat, add stock or broth, then add any combination of the following vegetables:
carrots, potatoes, green beans (the wide flat Italian green beans are my favorites), whole corn kernels, turnips, parsnips, kohlrabi, rutabaga, tomatoes, sweet potatoes, celeriac, bamboo shoots, water chestnuts, beets (only if you don't mid the soup being red or reddish), winter squashes (pumpkin, butternut, acorn...), okra (if you want the soup to develop a thickened almost gravy-like texture), peas, jerusalem artichoke.
If you can think of any other vegetables that can be simmered for days on end and not overpower the soup or get slimy or otherwise breakdown to render the soup less than tasty, please add them - and let me know what they are.
Bring to a boil and reduce the heat so the soup stays at a low simmer. I have a gas burner that's been stepped down so it holds a steady low simmer. This does double duty - it keeps the soup at a safe heat for days (better than a crock pot) and helps warm the kitchen. I always make sure the soup has plenty of broth in it and keep a lid on it so it doesn't evaporate and burn the contents. This is especially critical overnight or when I leave to work.
Every time you've eaten about half the soup, refill it with more broth and vegetables. Top the soup off with broth if it looks like it's getting too dry. It helps to have extra broth or stock in the freezer to add in.
This is a base soup. You can eat it as is at any time. I love having a bowl for breakfast because it's right there hot on the stove and ready to eat. It's a great midnight snack. And there's always enough soup for company.
And if you get tired of the flavor of this soup, you can alter it with minimal cooking - that list of food that you shouldn't simmer forever in your Backburner Soup can be cooked and stirred into a bowlful of the Backburner Soup. The mushrooms that were sautéed for flavor can be used as a garnish. Fresh or dried herbs can be added to subtly alter the flavor. Pour the soup over a few leaves of delicate fresh greens (baby spinach) or dried seaweed, they'll be cooked by the time you eat them.
Top the bowl of soup with pesto or salsa or a handful of shredded cheese.
Add a few cubes of cooked meat to the bowl.
You can season the soup with almost anything but salt. Save the salt to finish off the soup in the bowl, not the pot. It's far too easy to over salt Backburner Soup if you add a bit each time you top up the stock and add fresh veggies.
Why did I not recommend adding the meat to the soup? Because if you want meat, I always feel it's best to cook a little bit and add that to the bowl, not the pot. The meat used for the broth in the beginning is more as a flavor booster to enhance the stock or broth you used.
This soup does well with minimal attention and lasts through an average OK cold spell (2 weeks, generally).
There's a variant of this that we used to simmer on the back of the woodburning stove in Germany all winter long (4 months) that lacked meat so the soup kept its flavor. We used meat stock, but no actual lumps of meat in the soup. We also didn't put potatoes in it as they tended to disintegrate over time and thickened the broth too much. The goal was to have a rich veggie-filled broth for snacking on and sipping to warm up after being out in the cold and to use as a ready base for fuller meals.
It doesn't get cold enough in OK to need a 4-month Backburner Soup, but a 2 week soup is nice to have on hand - ready when you get in from work to sip for quick warmth and ready to add pasta, rice, cabbage, bacon, cheese, or other such things when you want a meal and not a warming snack.
This is some of my Backburner Soup a week in, poured over a bowl of noodles and served with crisp French bread. I also added a squeeze of lemon to brighten the flavor.