Select mature large, round tomatoes not small, cherry tomatoes. A key sign of maturity is the presence of gel-covered seeds inside. Cut the tomatoes from the vine (with stems intact to avoid damage- I use these snippers) or take fruit that has recently fallen to ground. There should be no sign of damage or disease.Handle carefully to avoid bruising.
Gently wash and thoroughly dry tomatoes.
Sort tomatoes by color/stage. This will make it easier to monitor changes.
Line box with lid with newspaper or other absorbent cloth or paper.
Place unripe tomatoes in box. Do not let tomatoes touch. Add a ripe banana or apple if tomatoes are green stage 1.
Take a photo to record appearance and date. Close lid.
Maintain even temperatures between 15-20°C (59-68°F), ideally at 20°C.
Check tomatoes every other day. Take photos to record progress. Remove any fruit showing sign of rot or mold. Switch out banana or apple as needed.Green tomatoes (stage 1) may take weeks to turn red.A pink tomato (stage 4) may only take days.