This tip comes via Cadrys Kitchen.

She explains how it works:

I made some room in the freezer.

Then I lined a baking sheet with parchment paper.

With a measuring spoon, I doled out tomato paste in tablespoon-sized dollops like red tomato-y cookies.

I then popped the sheet into the freezer until the paste patties were solid.

Once they were completely frozen separately, I just moved the solid tomato paste patties into a glass container.

Check out the tip for yourself at the link below.

Quick Tip: Freeze Tomato Paste and Never Toss a Moldy Jar Again| Cadrys Kitchen

Photo byfishermansdaughter.