Simple Homemade Spaghetti Sauce from Fresh Garden Tomatoes (Plus Easy Canning Instructions)

As a kid, my parents grew tomatoes and cucumbers every summer in their backyard city garden. I still remember those brown paper bags full of fresh veggies — eaten straight with garlic salt or tossed in summer salads. 
When we started our own garden at Blackbelly Ranch, I knew I wanted to recreate that same joy for my family.
My boys love cucumbers (fresh or pickled), but tomatoes haven’t won them over quite the same way yet. Even though we didn’t get overflowing paper bags, we still had a solid harvest — especially since I was the main one eating the fresh tomatoes! Not wanting any to go to waste, I grabbed about 2 pounds of extras and turned them into a fresh batch of spaghetti sauce.This recipe makes just enough for one pint (16 oz) mason jar — perfect for a small harvest. If you’re not canning, the total cook time is about an hour.
A Quick Note on Tomatoes
I used a mix of cherry tomatoes and two beefsteak tomatoes because that’s what we had. However, Roma or plum tomatoes are ideal for sauce — they’re meatier, have less water, and help the sauce thicken faster and nicer. I’ve since stocked up on heirloom Roma-style seeds for our greenhouse!

Ingredients & Tools (Makes 1 Pint)Ingredients:

  • About 1.75–2 pounds fresh tomatoes

  • 1 large yellow onion
  • 3 large garlic cloves
  • Handful of fresh basil
  • 1–2 tablespoons extra virgin olive oil
  • Salt, pepper, oregano, and any other spices to taste (optional)
  • ½ tablespoon tomato paste (optional, helps thicken if using watery tomatoes)
  • For water bath canning: ¼ teaspoon citric acid or 1 tablespoon bottled lemon juice per jar
  • For pressure canning: No extra acid needed

Tools:

  • Blender or immersion blender
  • Potato masher or large fork
  • Sieve (optional, for smoother sauce)
  • Large pot
  • Pressure canner or large pot for water bath canning (optional)
  • Canning supplies: mason jars, lids, rings, funnel, and distilled vinegar for wiping rims

Step-by-Step Directions

  1. Prep Your Ingredients
    Wash the tomatoes and score the bottoms lightly. Wash and roughly chop the basil. Slice or dice the onion and garlic (you’ll blend everything later, so size doesn’t matter much).
  2. Blanch and Peel the Tomatoes (Optional)
    Boil the tomatoes for a few minutes until the skins start to shrink and loosen. Transfer to ice water and peel. Save the skins for your compost!
    Note: I peeled every single cherry tomato the first time (painstaking!). Later batches I skipped peeling and just blended longer — it still turned out delicious. Your call!
  3. Build the Sauce
    In the same pot, warm the olive oil over medium-high heat. Sauté the onions until translucent, then add the garlic and cook until fragrant.
    Add the (slightly cooked) tomatoes, basil, and your chosen spices. Use a masher to help break everything down as it cooks.
    Once about half the tomatoes have released their juices, blend the mixture until smooth using a blender or immersion blender.
    If you want an extra-smooth sauce (or didn’t peel the tomatoes), run it through a sieve back into the pot.
  4. Simmer and Season
    Simmer the sauce, stirring often, until it reduces and thickens by about half. I sometimes add a touch of tomato paste on weeknights to speed things up and deepen the flavor.
    Taste and adjust salt, pepper, oregano, or other herbs. I kept ours simple with canning salt, home-dried rosemary, and oregano — measurements are more of a “feel” thing around here!

Once thickened, you can use the sauce right away, freeze it in a freezer-safe container, or can it for later.

Canning InstructionsPrep the Jars
Clean and warm your mason jar(s). Use a canning funnel to fill them with hot sauce, leaving proper headspace.

  • Water Bath Canning: Add ¼ tsp citric acid or 1 tbsp bottled lemon juice to each jar and stir. Remove air bubbles, wipe rims with a vinegar-soaked cloth, apply lids finger-tight. Process for 30–40 minutes (adjust for altitude).
  • Pressure Canning: No acid needed. Process at 10 pounds pressure for 20 minutes. Let pressure release naturally.

After processing, place jars on the counter for 24 hours to cool and seal fully. You’ll love that satisfying “pop” sound!Final Thoughts from the RanchThe end result? One fantastic jar of homemade spaghetti sauce that tastes like summer in a jar.
In the future, I recommend waiting until you have a bigger batch of tomatoes — this does take a little time and attention. I tried it on a busy weeknight after work and halfway through wished I’d waited (but powered through anyway!).
Second time around, I skipped peeling entirely and just blended longer — no sieve needed. This is a great base recipe — feel free to add extra veggies, herbs, or even ground meat (just freeze or pressure can if adding meat — water bath won’t work safely).
Have you tried making sauce from your garden tomatoes? I’d love to hear your tips or variations in the comments!

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