Prep to Cook: I pressure cooker or large saucepan with lid, vegetable knife, chopping board, teaspoon, hand-held stick blender, long handled spoon, freezer bags, lables
Prep: This is an all-in-one cook.
Ketchup has been sold for centuries to entice the consumer to eat more and enjoy meals. Making your own is a good way to use seasonal produce such as tomatoes from the greenhouse. Freezing it in pouches retains the fresh flavour and colour of the sauce.
Cooks Know How: Preserving fruits as a sauce or ketchup is a tradition of many countries round the world. Peri-peri for example. The process is simple, to render the fruits soft by breaking down their cellular structure. Boiling and simmering is the best method although you could experiment using the microwave if you have a suitable cooking dish. The heat will destroy microbes and enzymes to preserve the cooked sauce. During the cooking the flavours and colours from all the ingredients merge to create a piquant, smooth condiment. Vinegar is added as an acid that helps to reduce the pH and preserve the sauce, salt is also used to make conditions unsuitable for microbial growth. Sugar is added in a small amount for flavour rather than any preservative effect. If the sauce is bottled the sterilisation of the bottles is imperative, as yeasts could cause the bottles to explode during storage. To be on the safe side I would suggest freezing is the best method of storage. The Ketchup sauce is strong and tasty and can be used to enhance other sauces such as Bolognaise, stews, curries, soups and simple pasta dishes. Freeze in in portioned blocks for ease of use.
Try using excess squashes to make ketchup. Design your own sauce remembering the main rules that it must be processed by boiling and simmering, it must contain some vinegar and should have spice and salt.