Are you tired of putting a partially used can of tomato paste in the fridge, only to pull it out later and find its all rusty inside and the tomato paste is unusable?
OK, that was a trick question. You dont ever want to save any food in a can in the refrigerator. Its not only not healthy, it could be very dangerous. If you plan on using the tomato paste in the next few days, you can simply transfer the contents of the can into a seal-able plastic container, however if youre not sure when youll want to use it, freezing is your best option.
Heres the simple technique I use: Simply spoon out one tablespoon blobs of the tomato paste and put each of them on a plate covered with parchment paper. Place in the freezer until frozen solid, then remove each frozen serving from the parchment paper and place in a marked freezer bag or container. By freezing them first as individual tablespoon serving sizes, they wont stick together when you place them together in a freezer container.
When you need a small amount of tomato paste next time, just take out the number of tablespoons you need and add to your dish.
Having said all that, I like to use tomato paste from a tube, as shown in the picture, but when I was at the grocery store yesterday they were out of tubed tomato paste, so I decided to share this little tip with you.