- Tomatoes ripen best at 12-21 degrees Celsius.
- The best place to ripen them is in a warm place but not in direct sunlight.
- If you place the tomatoes in an area that has a temperature of about 20 degrees then they should ripen in about 7 days if stored cooler than 12 degrees they will take up to 30 days until they turn. This is actually a great way to make your fresh tomatoes last longer in storage. Some tomatoes can be stored up to two months after being picked.
- One thing I didn't realize is that small tomatoes that are immature (their skin is shiny), will not ripen after they have been picked. Only mature large tomatoes will turn.
One tried and true way that homesteaders and gardeners have used to ripen the tomatoes more quickly is to wrap each individual tomato in newspaper. You can also lay the tomatoes on a flat surface and cover them with a single layer of newspaper top and bottom. They should ripen in two weeks using this technique.
If you use this technique you will need to check them every few days for any tomatoes that may be getting squishy or rotten. It only takes one tomato to have a whole batch go bad.
If you are needing the tomatoes immediately, then in a smaller cardboard box at the warmer temperature place your tomatoes and add an apple to the box. Cover with newspaper. The Ethylene that comes from the apple will actually ripen the tomatoes very quickly so you can use them within a few days. No wonder you never store apples beside tomatoes in your cold cellar.
I hope this helps with any green tomato issues you might have!