Ketchup has been around since the 1690's, but was very different to the red gloop we're so fond of today. It was made in China out of pickled fish & known as kê-tsiap (meaning 'carp juice'. Yum). The sauce made its way to Malaysia where it was known as kechap & by 1740 British explorers had cottoned on to it, and started calling it ketchup. It wasn't until the early 1800's that it was made with tomatoes (and a lot of salt). Prior to that, most ketchups were made with mushrooms, oysters or walnuts, and were similar to soy sauce in consistency.
I know it seems a bit odd to make something yourself that is so cheap & readily available, but I love making my own ketchup. It's not just that I like making it out of yellow or green tomatoes & alarming friends & relatives with weird coloured ketchup (okay, so maybe it's a little bit of that) but the flavour is so much better than shop bought ketchup, and you can really mess around with your ingredients. I like to make a spicy red tomato ketchup with Mexican flavourings like cumin, oregano & a few minced up pickled chipotle chillis. Yellow tomato ketchup gets yellow mustard powder & ground ginger. So do whatever flavours you like.
The basic tomato ketchup recipe requires 1 litre of passata. My favourite way of making passata is to roast around 2kg of tomatoes, halved & arranged in a tray with whatever herbs you fancy (oregano or rosemary work well) in the oven at 180C until softened. Leave to cool & rub through a nylon sieve with a wooden spoon to get rid of all the seeds & skins. You should end up with about 1 litre of the tastiest pasta sauce you'll ever eat.
If you don't have a glut of tomatoes to use, you can still make ketchup with other fruits. Tomatillos make excellent ketchup (replace the lemon juice with lime & add a couple of green chillis for a spicy kick), as does rhubarb (2kg of rhubarb baked in the oven until tender & pushed through a sieve will make enough puree for this recipe, though I'd recommend leaving out the lemon juice as rhubarb is pretty tart). Elderberries, pineapple, mango, plums, bananas & gooseberries all make delicious ketchups too.
1 litre of passata
100ml red wine vinegar (or white wine vinegar if using yellow or green tomatoes)
100g sugar (or you can use honey)
juice of 2 lemons (about 50ml)2 cloves garlic, minced
1 tsp salt1 tsp oregano1/2 tsp cayenne pepper
1 tsp black pepper
Put all the ingredients into a pan & bring to a simmer. Cook, stirring regularly, until the sauce reaches & thick but pourable consistency (remember it will get a little thicker when cool). Pour into sterilised bottles & seal tightly. It sounds like an odd thing to do, but turn the bottles upside down & leave to stand for a few minutes (this is to sterilise the tops of the bottles & give them a longer shelf life). Use within 6 months & store in the fridge once opened.