You will need:
- a large pot for boiling tomatoes
- a large pot for boiling jars and lids (2 separate pots) This one should be tall, and have a cake rack in the bottom to keep the jars up off the heat.
- clean 500ml jars
- rings and lids for the jars
- something to pull the jars out of HOT water (they sell weird looking jar lifters and magnetic lid lifters where you buy the jars), and a ladle & large funnel.
- 4-5 tomatoes per jar.
- oregano, thyme, garlic if desired. Plain is the most versatile, already flavoured is the quickest to use.
- a wooden spoon
- something to test the PH (optional, fresh tomatoes boiled down are always under 4.6
Start with chopping the tomatoes to about 1/2 inch cubes, saving the juice in the pot, too. Dice the onions and add everything to the cooking pot. Add a teaspoon of sea salt, if desired.
Put on med-hi, and boil. Stir frequently and boil down by half. This should take an hour or so.
Pull the jars out of the boiling water, pouring the water back into the pot. Add a glug or two of vinegar.
Ladle each jar full of tomatoes, leaving 1/2 inch for headroom. Clean the rim of the jar with a damp cloth. Screw the lids onto the jars to just barely tight,. You should not be able to pick up the jar by the screw-band without it coming off.
THIS IS IMPORTANT, the lids must be help on by the rings but NOT tight. The jar can explode if the lid is too tight.
Make sure that the pot with boiling water is simmering. Gently place the jars of tomatoes in the pot, standing up. Some people put a cotton tea towel around and between the jars to keep them upright and not touching. There must be over an inch of water above the jar lids. If there’s less than an inch, pour in hot water and bring back to a boil.
Boil the water for 5 minutes, covered. Turn the heat off and remove the jars. DO NOT tilt the jars to pour the water off, keep them upright.
You should hear a satisfying “ping” as each one vacuum seals as it cools.
Now put them on the counter to cool, and stare at them in smug satisfaction. You now have additive free, fresh tomatoes for the dead of winter. Healthier and yummier than store-bought.