Mamaw Kitty’s “Mater, Tater, Onion Soup”

“Mater, Tater, Onion Soup” is a hearty and bright dish that captures all of the wonderful flavors of summertime tomatoes. This simple, yet satisfying, soup is one of the most beloved and cherished recipes passed down by my paternal grandmother.

Mamaw Kitty always had a house full: grand-kids, nieces, nephews, and plenty of extra tag-a-longs. Any given summer night, she would have 7 or 8 well fed kids sleeping on pallets in her living room floor. One of the dishes that she fed us all frequently was this soup. Now that we are all grown, we make this for our own little tribes. The kids love it. Friends love it. We all love it.

This soup is so incredibly straight forward. If you were to  have asked my grandmother for a recipe, she probably would have answered, “It’s just maters, taters, and onions.” For years, I have had many people ask me for this recipe, and I have always said that it is really just the magic of those three simple ingredients. But, I have finally decided to work out some basic measurements and the process for making it. I’m sure each of my cousins have their own variations of our grandmother’s original, but we all still keep it pretty basic. My version is totally vegan, and I have added a few seasonings and tiny touches to make this a more suitable recipe for canning.

As is the case for most beautifully simple foods, the quality of the ingredients is key. Vine ripened summer tomatoes make the best soup. If you grow your own potatoes and onions as well, you are in for a real treat. Two years ago I made a batch of this soup entirely from home-grown vegetables, and it was incredibly satisfying to know I did not have to purchase any of the main ingredients. I did the same this year and made a double batch with ingredients from our gardens: Yukon gold and Red Lasoda potatoes, Candy and Super Star onions, and a myriad of assorted tomatoes.  This soup is good if it is made from store-bought ingredients, but it is really amazing with fresh home-grown veggies.


I make and can this every summer when our counter tops start filling up with tomatoes. We rely on batches of this soup to provide easy weeknight dinners all winter long. “Mater, Tater, Onion Soup” with grilled cheese sandwiches is one of our favorite family meals. It is also really great when served with fresh cornbread (how my Mamaw served it). But, you could ladle this soup with no accompaniment and it would still be a wonderful meal.

Making a canner full of this soup is a bit time-consuming, but worth all of the effort. In the middle of Winter when I am missing sweet Summer tomatoes, I can open a jar of this soup and feel the warmth of July. There is really no better way to can tomatoes.



Yields approximately 7 quarts.

  • 3 sweet onions or whatever large onions you have
  • 8 quarts of fresh whole tomatoes (2 standard sized woven chipwood/peach baskets) I use assorted tomatoes including yellow, green, and black heirlooms.
  • 1 dozen large new potatoes
  • juice from 1/2 lemon
  • 1 teaspoon balsamic vinegar
  • 1 teaspoon celery seed
  • 1 pint vegetable broth
  • 1 pint water
  • 1 teaspoon salt
  • 1 teaspoon sugar
  • 1/2 teaspoon black pepper
  • 1 teaspoon dried thyme
  • 1 tablespoon olive oil


  • Dice onions to desired size. I usually leave the pieces fairly large because I like a chunky soup.
  • In a large stock pot, slowly saute half of the diced onions in the olive oil. The remaining half of the onions will be added to the soup without being sautéed. You could caramelize all of them or throw them all in without being caramelized. This is just a little step that I add to enhance the flavors of the onions and soup.
  • While the onions are slowly cooking, start peeling the tomatoes. I handle this task differently depending on what product I am making. For this recipe, I prefer scoring an X in the skin on the bottoms of the tomatoes, very quickly heating them in boiling water, and then shocking them in an ice-water bath to loosen the skins. After the skins have been removed, remove the tough stem end of the cores. Roughly chop the tomatoes and toss them in with the sautéed onions. Seeds and all juices should go in the stock pot as well.20180715_160008
  • Keep the heat on low as you continue to add tomatoes to the stockpot. Slowly simmer the tomato and onion mixture for 15 minutes after you have finished adding all of the tomatoes.
  • Add the vegetable broth, water, and seasonings.
  • Peel and cut potatoes into small bite sized pieces and add them to the stock pot. Simmer for an additional 10-15 minutes. The potatoes should still be firm but not raw. If they are cooked too long, they will be too soft and fall apart during the canning process.
  • Add balsamic vinegar, lemon juice, sugar, and any additional desired salt. (Taste the soup and use your own judgement, just don’t go crazy with the salt.).
  • At this point you have enough soup to feed an army. You could simmer it for 10-15 more minutes and feed an army…..or you can proceed to the canning instructions. IMG_6017

Canning Instructions

This soup and any other foods containing potatoes should be pressure canned in order to be considered safe. The vinegar and lemon juice added to this soup are to enhance flavors, but are not added to increase acidity in order to safely lower processing times or water bath can. Potatoes should be peeled.

  • Sterilize jars. Ladle hot soup into hot jars, leaving 1″ headspace.
  • Clean jar rims with a damp paper towel.
  • Apply 2 piece canning lids.
  • Process in a pressure canner for 40 minutes at 11 lbs of pressure (sea level). DO NOT processes this in a water bath canner. If something contains potatoes, I pressure can. There are no actual government approved recipes for soups containing only potatoes, tomatoes, and onions. However, the recommended time for processing onions and potatoes is 40 minutes. So, that is the process time that I use to can this recipe every year. If you wish to process according to National Center for Home Food Preservation guidelines for vegetable soup, please refer to this link
  • If you double this recipe, bring the soup for the second batch up to a simmer before filling your second batch of jars. Do not fill all of the jars at one time. Only fill the jars that will fit in you canner at one time.

I always try to save our jars of soup until the cold dreary days of winter.  I’ll be sipping this soup dreaming of all the glorious tomatoes we will be growing next Summer.

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