Transformation
The transformation or processing stage of the food system can have many different steps and types of transformation, including preservation. Chef Ryan will take us through how to preserve tomatoes at their peak ripeness to enjoy all winter long.
The best varieties of tomatoes to use for preserving are thick walled Italian plum tomatoes such as Roma or San Marzano tomatoes. They do not have a lot of seeds and have a very low water content.
After blanching and peeling, tomatoes can be transformed in another recipe or preserved through freezing or canning.
The transformation or processing stage of the food system can have many different steps and types of transformation, including food preservation. Food preservation is saving food for later, like turning strawberries into jam, or tomatoes into tomato sauce! Chef Ryan will show us how to make a tomato sauce and preserve it through water bath canning.
People have been using different methods of food preservation for thousands of years to keep food from spoiling. Canning is a relatively new method of preservation that was invented in the 19th century. Nicholas Appert devised this method by storing food in containers that are sealed and then sterilized by heat. The process was invented in response to a call by the French government for a means of storing nutritious food for army and navy use. Napoleon said “an army marches on their stomach”, and soldiers were sick and dying of scurvy, a disease caused by a lack of nutrients from vegetables and fruit. This method developed into the process that we use today that allows us to fill grocery store shelves with affordable and healthy canned foods!
If done correctly, canning is a very safe and effective method of food preservation. Ensure you are following every step carefully to prevent contamination and avoid foodborne illness. We recommend that you consult your local health department’s guide on safe canning procedures before you take on canning at home.
Watch chef Nick transform tomatoes into his favourite condiment - ketchup!
The process of making ketchup is not hard, but can be tricky to master because it's such a familiar texture and flavour!
The main producers of ketchup that we see at the grocery store have huge machines at their factories that make sure their ketchup is the perfect consistency every time. It can be difficult to master this at home, but it's a great opportunity to experiment and have fun!
Ketchup is not runny or too stiff and has the perfect "gloopy" consistency that is a mix between a liquid and a solid. This is called a non-Newtonian fluid. Other examples of non-Newtonian fluids are shampoo and toothpaste.
What this means is that the viscosity of the ketchup changes depending on the amount of force exerted on it. Imagine for a moment you have a glass ketchup bottle; if you tap on the bottle a small amount it comes out slowly, but hit it with force and you will end up with ketchup all over your plate! Can you think of any other examples?
Transform some tomatoes and make ketchup at home!
What is ketchup made from and how does it happen? Hover over the numbers to learn more about each step!
For more agri-food programs, resources, and education, connect with the following organizations to learn more!
