In a large slow cooker, mix together the broth, diced tomatoes, salt, pepper, oregano, bay leaf, garlic, onion powder, zucchini, carrots, and green beans. Stir in cabbage and red wine if using.
Cook on low for 8-10 hours or high for 4-6 hours.
Turn the slow cooker to high. Add in the pasta and cook for 20-30 minutes until pasta tender.
Remove bay leaf, stir in vinegar, and serve with a generous grating of Parmesan.
Tomatoes: If you have textural issues with diced tomatoes, replace them with tomato sauce or crushed tomatoes. Marinara: For the BEST flavor in minestrone soup, use your favorite prepared spaghetti sauce or marinara. Vegetables: Add any vegetables you like to this soup--chopped zucchini, carrots, green beans, yellow squash, celery, etc--whatever your family likes or you have on hand.Using Spinach instead of Cabbage: If you prefer spinach over cabbage, omit cabbage and stir in spinach when you stir in the red wine vinegar and let wilt before serving. Beans: Kidney beans, cannellini beans, northern white beans, and pinto beans all work in Minestrone. Use all of one variety or mix and match. Red Wine: Use a dry red wine, such as Merlot or a Cabernet, to add additional flavor and depth. But feel free to omit it.Broth: If you don't have vegetable broth and are not vegetarian, chicken stock works just as well in this soup.Storage: Store leftover Minestrone soup in a sealed container for up to 5 days or freeze for up to 3 months. You may need to add a splash of stock or water before warming up as the noodles absorb the stock as as they sit.