Quick Methods to Ripen Tomatoes Indoors

Why Ripen Indoors?

Tomatoes need warmth, not sunshine, to finish ripening. While vine-ripened tomatoes are often praised for their flavor, indoor-ripening is sometimes necessary due to early frost, disease risk, or pest pressure. If you end up with under-ripe tomatoes late in the season—or want to enjoy an extended harvest—using controlled indoor methods ensures fewer losses and more consistent ripening.gardenbetty+1

The Science Behind Tomato Ripening

Tomatoes, as climacteric fruits, naturally produce the plant hormone ethylene, which triggers and accelerates their ripening. This process includes color change, softening, and sugar development. Because green tomatoes off the vine still produce ethylene, they can complete this journey indoors.bbcgoodfood+1

Selecting the Right Tomatoes

• Choose mature green tomatoes—those that are full-sized and glossy, or showing a slight “blush” of color. Very small or hard immature fruit are unlikely to ripen well and may rot.

• Avoid bruised or blemished tomatoes, which are prone to spoilage during the ripening process.

• Keep the stems attached if possible, but take care not to damage other tomatoes—they’re best ripened in a single layer for airflow.thisunboundlife+1

Quick Indoor Ripening Methods

The Paper Bag Method

One of the quickest and most effective ways! Place several unripe tomatoes in a paper bag, preferably with a ripe banana or apple. Both the tomatoes and the companion fruit emit ethylene gas, which gets trapped in the bag and encourages the tomatoes to ripen.gardenersworld+2

• How-to: Add tomatoes and a banana or apple to a brown paper bag. Fold the top but allow some air circulation to prevent mold.

• Speed: Tomatoes often ripen in 3–7 days depending on their initial color and local temperature.

• Tip: Avoid plastic bags, which retain too much moisture and promote mold and rot.gardenbetty+1

The Cardboard Box or Tray Method

Spread tomatoes in a single layer in a ventilated box, drawer, or tray lined with newspaper or brown paper. You can layer tomatoes with newspaper in between if you have many to ripen at once.thehouseandhomestead+2

• How-to: Line a box or tray with newspaper, place a single layer of tomatoes, then add a sheet of newspaper and another layer if needed (limit to two or three layers for easy checking). Store in a warm (not hot) room out of direct sunlight.

• Tip: Place a banana or apple in the box to increase ethylene and speed ripening.

• Speed: Most tomatoes ripen in 7–14 days.thehouseandhomestead+2

Wrapping Tomatoes in Newspaper

This method is perfect for handling small batches or when space is tight.

• How-to: Wrap individual green tomatoes in sheets of newspaper and store gently in a box, basket, or shallow bin.

• Speed: Typically 7–14 days.

• Note: This helps slow down ripening—great for extending your supply and preventing many tomatoes from over-ripening simultaneously.foodgardenlife+1

Fruit Bowl or Counter Ripening

If only a handful of tomatoes are nearly ripe, keep them in your fruit bowl—surrounded by other fruit that emits ethylene—or simply on the kitchen counter at room temperature (18°C–25°C / 65°F–77°F). Warmth accelerates ripening, while cool slows it down.bbcgoodfood

• Speed: Ripening may complete in 3–5 days if fruit already shows color.

The Windowsill Method

Some gardeners advocate ripening on a sunny windowsill. This works for tomatoes that are already starting to turn but isn’t essential for green ones—sunlight isn’t required and can sometimes cause uneven ripening or tough skins.reddit+1

• How-to: Place near (not touching) a sunlit window. Turn tomatoes occasionally for even ripening.

• Speed: 3–5 days for tomatoes with a blush; longer for green.masterclass

Tips for Best Results

• Room Temperature Matters: Ideal temperatures are between 18°C–25°C (65°F–77°F). Lower temps slow ripening; too much warmth can affect texture and flavor.bbcgoodfood

• Monitor Closely: Check tomatoes daily, removing any that show signs of rot or have finished ripening.

• Airflow Is Key: Proper ventilation prevents mold and moisture build-up.

• Harvest Before First Frost: Green tomatoes exposed to cold (below 10°C/50°F) may not ripen well or may develop poor flavor.gardenbetty+1

What About Ethylene?

Ethylene is the natural gas produced by apples, bananas, and ripe tomatoes. Pairing these fruits accelerates ripening. This is the science behind the paper bag and banana trick—bananas are especially potent ethylene producers.gardenersworld+2

Ripening Whole Tomato Plants

For a bumper harvest late in the season, you can pull up the whole tomato plant (roots and all) and hang it upside down in a dry, frost-free, airy place such as a garage or shed. Fruit may ripen slowly over several weeks.bbcgoodfood

Methods to Avoid

• Plastic Bags/Jars: These trap too much moisture, virtually guaranteeing mold before tomatoes ripen.bbcgoodfood

• Cold Spots: Never store tomatoes in the refrigerator or in places cooler than 10°C (50°F) until they’re fully ripe—the process slows, and texture suffers.

• Unripe, Tiny Tomatoes: Tomatoes picked too immaturely will not ripen and may rot.

Common Mistakes

• Overcrowding: Too many tomatoes bunched together promote rot and uneven ripening.

• Ignoring Mold or Rot: One rotten tomato can ruin the whole batch—remove bad fruit immediately.thehouseandhomestead+1

• Letting Overripe Tomatoes Go Unused: Store ripe tomatoes in the fridge only if you can’t eat them right away to slow decay, but bring them up to room temperature before eating for best flavor.

Frequently Asked Questions

Is sunlight necessary?

No. Tomatoes ripen from the inside due to ethylene gas and the natural conversion of starches into sugars; direct sun is not required.thisunboundlife+1

Will tomatoes picked very green ever ripen?

Only if they are mature green. Small, hard, immature tomatoes likely won’t finish ripening or taste good.thisunboundlife+1

Can I speed up ripening further?

Raise the room temperature slightly (but don’t exceed 30°C/86°F), add an extra ripe banana or apple, and check for color daily.

Conclusion

Ripening tomatoes indoors is simple, and using methods like the paper bag trick, the box-and-newspaper approach, or simply leaving them with other fruit on the counter ensures you won’t waste the bounty of your garden. Remember: harvest only full-sized, mature green fruit for best results; use warmth and ethylene to your advantage; and check often for perfectly ripe tomatoes. With a little vigilance and the right environment, you’ll enjoy homegrown flavor well beyond the last days of summer.foodgardenlife+6