Main mistakes in autoclaving

However, despite the convenience of home autoclaves, things can still go wrong from time to time. This is bad because incorrect use can ruin the tins you make and ruin the whole result. To avoid mistakes when using the autoclave, follow the rules described in the autoclave user manual.

Error No 1. Too much water is being poured into the autoclave. If you ignore the instructions and fill the autoclave to the brim, or just more than 2 cm above the top of the jars, you will probably ruin the canning process. The water in the autoclave expands, and if you do not leave the necessary air space, the pressure in the tank will become too high, leading to an emergency valve activation.

Error No 2. When using a pre-pressurised autoclave, the pressure in the autoclave should be set to exactly 1bar, there is very little margin for error. In case of overpressure, an emergency valve may be triggered.

Error No 3. Always leave extra space in the jar, about 2 cm above the lid. Strong heating of foods causes them to swell and they can push the lid off. To avoid this, leave a space of 2-3 cm so that the lids pull inwards instead.

Error No 4. Lack of water in the device. Regardless of the number of jars and the volume of the autoclave, it must be filled with water to cover all the jars by about 2 cm. Thanks to the right amount of water, all the jars heat up evenly. A steady, gradually decreasing temperature is also important during cooling.

Error No 5. Do not open the autoclave until it has cooled completely. After canning is complete and the heating is turned off, many people want to open the appliance immediately and check the contents. Do not unscrew the nuts until the autoclave has cooled completely below 30c. In this case, the pressure in the device corresponds to the pressure in the cans. If you open the autoclave too early, the lids can come loose.

Error No 6. Lack of the necessary density. You must tighten the nuts evenly to ensure tightness. Tighten the nuts across the lid crosswise, not in a row. If tightened incorrectly, the lids can come loose and the pressure can either rise too slowly or not rise at all. In the case of complete hermeticity, the pressure in the vessels increases gradually.

Error No 7. Incorrect closing of cans. Before the procedure, the metal lids should be kept in boiling water until the seal is soft. Always use new cups. Choose high-quality lids from reliable manufacturers and make sure they are intact.

Error No 8. Wrong autoclave mode. Follow the prescription or manufacturer’s advice. Do not pressure cook fruit for 1 hour at 120°C when the cooking instructions say 15 minutes at 100°C. Do not leave the autoclave unattended for long periods.

If you manage to avoid the main mistakes, a quality result is guaranteed!

Read more:

Autoclave operating modes

What is an autoclave

How to use autoclave

How to choose an autoclave