Sterilising jars is really important when you are preserving. If there is any unwanted bacteria in a jar, your beautifully hand made preserves will spoil, and we don't want that!
You can use any jars to preserve in as long as they are heat proof.
If you are buying them from a company that makes them for preserving purposes, you are good to go.
But what if you want to re-use jars from the supermarket?
Well basically, if the jar/s in question have contained pickles, chutney's, vegetables or jam, they would have all been heat treated, so you are pretty safe to re-use those.
However, the lids are another matter. As long as the lid is metal, has no visible signs of rust or deterioration and have a rubber seal underneath like the photo below, you can go ahead and use them.
You can see the white thin rubber seal on the lid on the left below.
This is needed so that the jar seals really tightly once the hot preserves are inside. It helps to create suction to eliminate any air getting inside and spoiling the preserves.
PLEASE NOTE: do not use jars that you have purchased from discount stores. The glass in them is really thin and not heat proof. Leave them to store your dried spices and flour etc in.
Step 1 - Thoroughly wash your jars and lids in hot soapy water.
Step 2 - Rinse with clean water and leave to drain upside down.
Leave them in there for around 15 minutes.
Step 4 - Meanwhile, put your lids into a saucepan and fill with water until they are covered. Bring to the boil, then boil for 5 minutes. Remove them from the pot using tongs and place onto an airing rack to air dry.
Or, if you are impatient like me...use paper towel to dry thoroughly.
Step 5 - After the jars have heated for 15 minutes, turn off the oven and leave them in there to keep them warm until you're ready to fill them. Or, remove if you're using them for another purpose.
Now that was pretty easy wasn't it!