Some of these steps may seem unnecessary, please bear in mind that I am writing this primarily for my nineteen-year-old son who has just moved into his first flat.
Clear and scrub the bench and sinks.
Now boil your kettle.
While that is happening, fill the sparkly clean sinks. The smaller one with hot water to heat the steel. The larger one with cold water.
Put your tomatoes into the hot water, then let most of the water out. Use a fork to lift the plug if the water is too hot for your hands. Or put on a rubber glove. Now pour the boiling water from the kettle over the tomatoes…
The tomato skins will now slide off easily. This is called blanching Trim off the top, peel and chop the tomatoes.
Prepare a heavy bottomed tall sided skillet with about 1 tablespoon (Tbsp.) of extra virgin olive oil, also known as EVO. Pour it in and swill and tip the pan until the base is covered.
Put your tomatoes into this pan.
Clean down the bench and board. You should have a scrap bowl of skins and trimmings and a pot of chopped tomatoes. Nice and clean.
Put the pan on a medium heat and bring to a steady slow simmer, stirring regularly.
Stir occasionally to prevent the chopped tomatoes from sticking to the base of the pan. Cook for about 40 minutes or until the fruit is broken down and soft.
Prepare a shallow baking tray. The size will depend on how much cooked pulp you have. You want to get an even thin layer no more than 10mm deep. Drizzle a small amount of EVO in and spread out evenly with your fingers.
Now pour your pulp through a fine sieve into the tray. If you have a food mouli even better. I don’t -so a sieve it is. With the back of a soft spatula or spoon gently push the paste through the sieve…
… until all that you have left is seeds and fibres.
Scrape off the back of the sieve and pick out any stray seeds… Shake the tray gently to get a smooth even layer.
Put into the centre of a low temperature oven, around 90 – 95°C. This process can take a few hours so keep checking. You are slow roasting and evaporating. Avoid a tough skin forming. After the first hour the paste should be thickening and just starting to pull away from the sides.
With a spatula or scraper pull the paste together, mix and re-spread into an even layer. Ensure there are no thin areas that could cook faster or burn.
Repeat this process every 30 – 40 minutes until the paste is thick and spreadable. On the last bake put you washed clean jar into the oven with the paste.
After you remove the paste turn the oven up to 110°C to complete the sterilisation of the jar, remove the jar as soon as the temperature indicator goes out, usually 3-4 minutes.
Spoon your paste into the sterilised jar, smooth the surface and cover with a thin layer of EVO. Store in the refrigerator.
So this is about 120ml of paste from 1.2kg tomatoes. It is delicious.
So I think the ratio would be 100g of tomatoes gives 10mls of paste. My maths is OK but you should check yourself. I may be having a vague day.