• Wash and roughly chop the tomatoes into large chunks. There is no need to peel or seed them now; the food mill or sieve takes care of that later.
  8 Pounds roma tomatoes
  
• In a large, heavy-bottomed pot, heat the olive oil over medium heat. Add the tomatoes and simmer for 20 to 30 minutes, stirring occasionally, until they have broken down and are swimming in their own juice; you are looking for soft, collapsing pieces of tomato, not a dry pan.
  2 Tablespoon Olive oil
  
• Pass the cooked tomatoes through a food mill to separate out the skins and seeds. Discard the skins and seeds; you will be left with a smooth, seedless tomato pulp.
  
• Return the tomato puree to the pot. Add the bay leaf and simmer on low heat for 1.5 to 2 hours, stirring frequently, until the mixture has reduced to a thick, scoopable paste. The last thirty minutes are when this scorches fastest: as the paste thickens, it goes from a gentle simmer to catching on the bottom of the pot in a hurry, so stay close, stir often, and drop the heat as it tightens up. Pull out the bay leaf before you move on to storing.
  
• You have two good options for this version: portion and freeze it (see the freezing methods below), or refrigerate it in an airtight container for up to a week for near-term use. Because this recipe includes olive oil and no added acid, it is not tested for shelf-stable canning; do not process it in a water bath. If you want a canned, pantry-stable tomato paste, use the tested method further down this post instead; it uses a different ingredient list built for that purpose.
  1 each Bay leaf

How to freeze tomato paste in portions

• Pipe or spoon the tomato paste into each cavity of a silicone mold, filling each one level with the top. If you do not have a pastry bag, snip the corner off a resealable plastic bag for easy piping.
  
• Place the mold in the freezer until the tomato paste is completely frozen, usually several hours or overnight.
  
• Flip the mold over, and the frozen portions will pop out easily. If any stick, run the bottom of the mold under warm water for a few seconds first.
  
• Transfer the portions to an airtight, freezer-safe container and press out as much air as possible.

How to Can This Tomato Paste Safely

• Wash and rinse half-pint canning jars, and keep them hot until you are ready to fill them. Prepare your lids according to the manufacturer's directions.
  
• Rinse the tomatoes, remove the cores, and chop them into ½ to ¾-inch pieces; there is no need to peel them yet. Place them in a large stockpot, cover, and bring to a boil, stirring as needed to prevent burning. Reduce the heat, remove the lid, and simmer uncovered for about 1 hour, until the volume is reduced by half, stirring frequently to prevent sticking and burning.
  
• Press the cooked tomatoes through a fine-mesh sieve or a food mill fitted with a fine blade. Do not use a blender or food processor here; they whip air into the tomatoes in a way the tested processing time does not account for.
  
• Return the sieved tomatoes to the pot and stir the citric acid in thoroughly; this matters, since the acid needs to be distributed evenly through the tomatoes rather than dropped into the jar later. Stir in the salt, bay leaves, and garlic if using. Continue cooking uncovered on medium heat, stirring frequently, until the paste rounds up on a spoon and the volume has reduced by half again, about 2.5 hours more. Watch closely near the end; this is exactly the stage where it scorches fastest.
  
• Remove the bay leaves and garlic clove. Fill the hot paste into your hot, clean half-pint jars, leaving ½-inch headspace. Remove air bubbles, wipe the jar rims clean, and apply your lids.