How To Ripen Green Tomatoes

It’s the end of the gardening season and nighttime temperatures are dipping into the low 40s. Rather than letting green tomatoes rot on the vines, you can bring them indoors and ripen them reliably with a few simple, science-based methods.

Why So Many Tomatoes Are Picked Green

Most commercial tomatoes are harvested green to withstand shipping. They often appear red on the outside but can show pale flesh just under the skin. A truly vine-ripened tomato is red throughout—our goal is to mimic that quality at home.

Pre-Frost Tip: Encourage Ripening on the Vine

About a month before your expected frost, turn off irrigation. You don’t want plants to wilt, but a slight, controlled stress nudges them to prioritize ripening fruit.

Note: Stop short of visible stress or leaf curl. We’re encouraging—not punishing—the plant.

What You’ll Need

10×10 in cardboard boxes (or paper bags for small batches)
Kraft or newsprint paper (absorbent layers)
Clean, dry tomatoes (remove mud; no washing right before storage)
Cool room or pantry space

Step-by-Step: Ripening Tomatoes in Boxes

Line the box: Add a sheet of paper to absorb moisture and protect the box from any fruit that spoils.
Place tomatoes stem-side down: The stem end is firmer and less likely to bruise; this position also reduces moisture loss around the scar.
Layer with paper: Add a thin paper layer between tomato layers to limit bruising and cross-contamination.
Group by similarity: Keep tomatoes of similar size and color together so they ripen at the same pace.
Close the lid: A mostly closed or sealed box traps ethylene and accelerates ripening.
Check daily: Remove any damaged or overripe fruit immediately.

Pro tip: Small batch? A paper bag works well—roll it mostly closed to retain ethylene while allowing a little airflow.

Ethylene Gas: The Science Behind Ripening

Tomatoes produce ethylene, a natural plant hormone that triggers ripening. A closed container concentrates this gas, which speeds uniform color and flavor development.

FYI: Ethylene disperses upward readily; a closed lid helps keep it near the fruit. Crates with many vents are designed to slow ripening during transport.

Experiment idea: Compare a sealed box vs. a box with a small fan. Which ripens faster and more evenly? (Stay tuned—I’m testing this!)

Temperature Guide

Temperature	Effect on Ripening	Notes
65–70°F (18–21°C)	Faster ripening	Good for quick turnaround.
55–60°F (13–16°C)	Slow ripening	Great for staggering batches without hurting flavor/texture.
~50°F (10°C)	Ripening nearly stops	May damage cells, degrading flavor and texture if prolonged.

Warning: Avoid sustained temps near 50°F if you care about peak flavor/texture—use only to pause ripening briefly.

Sorting for Even Ripening

Keep boxes consistent. Don’t mix green and red fruit—red tomatoes will overripen and rot before green ones catch up. Likewise, separate small and large tomatoes; size affects ripening speed.

What I Do With Big Batches

I prefer 10×10-inch boxes because they stack neatly and are perfect for sharing with friends and neighbors. For my pantry workflow, I let most of a batch ripen together so I can process and jar them at once.

Once boxed, it’s simply a matter of time—watch for color change and enjoy! A day-by-day time-lapse is a great way to visualize the process.

FAQs

Should I wash tomatoes before boxing?

Brush off dirt and dry them; avoid washing immediately before storage to prevent excess surface moisture.

Can I add a ripe banana to speed things up?

Yes—bananas release ethylene and can accelerate ripening in a closed container.

Is stem-side down really better?

Yes. The stem end is structurally firmer and loses moisture more slowly, which helps reduce bruising and rot around the scar.

Paper bags vs. boxes?

Paper bags are great for small quantities. Boxes handle volume, layer well with paper, and stack for space efficiency.

Thanks for reading!