Split Pea Soup

I got this recipe off the Internet years ago. It wasn't exactly like I've posted below but this is the way I have modified it and like it. You could omit the step to puree the soup and serve it chunky if you prefer. Also the original recipe called for 3 to 4 Tbsp of red wine vinegar, however that's too much vinegar for my taste.

2 stalks celery, diced
2 carrots, diced
1 onion, chopped
3 bay leaves
1 tsp marjoram
1/2 tsp thyme
1 1/2 cups dried yellow split peas
8 cups water
1 medium potato, peeled and diced
1/4 cup fresh parsley, chopped or 2 Tbsp dried parsley
2 Tbsp red wine vinegar
salt and pepper to taste

Saute onion, celery, carrots and bay leaves in water until soft. Add marjoram, thyme, split peas and water and bring to a boil. Lower heat to medium-high and cook until the split peas are soft, about 50 to 60 minutes. Add extra water if needed. Add potatoes and parsley and cook another 10 minutes or until potatoes are soft. Remove from heat, puree in batches in a blender. Add vinegar, mix well, salt and pepper to taste and serve.