Twist-off jars: use & storage
screwing jar
Do you have twist-off glass jars with metal lids? Here are some tips on how to close and store these glass jars and twist-off lids.

Tips about how to close & store twist-off jars 


How to close twist-off jars  


Most of the time twist-off jars are closed by a machine. If you close your jars manually with a metal twist-off lid, here are some recommendations:


  • First of all, you can heat the lid to soften the liner very slightly. This will reduce the pressure on the lugs and create a better seal. However, be careful not to exceed 60° when heating the twist-off lid. This step is ideal for cold filling.
  • Then, you can place the screw lid on the jar and turn it 1/4 turn clockwise without forcing so as not to strip the threads and/or risk damaging the liner.


Here's a tip to make sure the metal lid has been properly positioned: 

Make a mark on the glass jar at the beginning and end of one thread, then make another mark at the beginning of one lug on the twist-off lid. The photo below shows an example of what we mean: 


twist-off jars  


Then place the metal lid on the jar. The twist-off lid is properly positioned on the small glass jar if the mark on the twist-off lid is about 1/3 of the way past one of the two marks on the jar. 


twist-off jars  


The lug of the metal lid must be between the two marks on the glass jar. 

If it is more than 1/3 of the way past the beginning of the mark onthe glass jar, it means that the metal lid has been overtightened and may shift, thereby breaking the vacuum. In this case, it’s better to start over with another screw lid, since an overtightened lid has probably been deformed. 

If it is less than 1/3 of the way past the mark on the glass jar, it means that the metal lid has not been screwed on tightly enough. It must be tightened, otherwise the lid may pop off if the container is subjected to an impact. 


How to store twist-off metal lids

If you have heated the twist-off lids before hand, wait for themto cool completely before storing them. 

Screw lids and glass jars should not be stored immediately if they are wet, since the metal lid may rust. Make sure they are dry before storing them. 

Similarly, the storage room should not be exposed to moisture and should be well ventilated. This will prevent condensation.

Finally, glass jars and metal lids should not be stored near corrosive substances. 

For any other questions about twist-off jars, please contact us at!

You may also be interested in this other article about twist-offjars: "Twist-off jars: pasteurization & sterilization"


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empty glass jar