This is going to be a pictorial post about how I make passata. There are probably more correct or more traditional methods, but with the resources I have available this is the way I do it.
As you will see, I peel my tomatoes, but that part is optional. I think it makes for a better texture to not have tomato peel in my cooking. You can also skip the reducing stage and process your jars straight from cold, but you will end up with a lot of water in your jars this way.
As well as plenty of ripe tomatoes and some salt, you will need:
Two large saucepans
A couple of large bowls
Food processor or blender
Funnel – a regular funnel is fine, but a wide-mouthed canning funnel will make life a bit easier
Empty jars – about one per kg of unprocessed tomatoes, plus a spare just in case
Stovetop of countertop preserving unit
Step 1 – Source your tomatoes. Bigger fruit are better as they are quicker and more efficient to skin. Saucing varieties with fewer seeds are ideal. I used a mix of Hungarian Heart and Amish Paste, with a couple of rogue San Marzanos.
Step 2 – Slice their bottoms. This makes them easier to peel as the skin will split where the slice is.
Step 3 – drop tomatoes a few at a time into boiling water. Leave them for a few seconds – the exact time depends on the size and variety of tomato, but about 10 seconds is a rough guide.
Step 4 – scoop your tomatoes out of the boiling water and into a bowl of cold water.
The skins should slide right off.
This will leave you with a bowl of skinned tomatoes and a bowl of skins in water.
Worms love tomato skins, so if you have a worm farm you can tip the skins, water and all, into your worm farm.
Step 5 – chop your tomatoes into pieces if they are very big and discard any hard green cores. Put your chopped tomatoes into the blender.
Chickens, ducks and geese love bits of tomato. Cats not so much.
Step 6 – process the tomatoes until most of the lumps are gone. This may be the point at which you realise you have put too many tomatoes in the food processor, so make your next batch a little smaller if this is the case.
Once processed the tomatoes will look pale and be thin and frothy.
Step 7 – reduce the tomato puree. You may want to add salt at this stage, the information I was able to find said 1tsp of salt per kg of tomatoes.
Simmer until the tomatoes have reduced in volume by about half and started to thicken.
Taking a ‘before’ photo can help you know when you have got the level of the tomatoes in the pot down to about half. This takes about an hour, depending on how many tomatoes you are processing and the peculiarities of your stove.
Step 8 – pour the passata into jars (recycled passata jars are ideal). There are a few ways to process from here, but I do a hot water bath because I need to keep my jars in the cupboard for up to several months.
Follow the instructions on your preserving kit.
Once the jars have cooled make sure that all the seals on the lids have popped down. If any have not store those jars in the fridge and use them first. The others can go into your storage space.