Growing hot peppers in cooler climates, you may find unripe green peppers on your plants as the gardening season ends.
In zone 7, we face this situation at the end of summer as days get shorter and the temperature drops.
But worry not. There are simple-to-follow methods to ripen your green peppers indoors.
Just the facts: You can ripen green unripe peppers indoors on a window sill, in a box, or brown paper bag or by moving the plant or parts of the plant indoors. Ideally, wait for peppers to blush and show signs of ripening before you pick them. Placing a ripe fruit with your unripe fruits will speed up the ripening process as the ripe fruit produces a gaseous plant hormone called ethylene that induces fruit ripening. 
3 simple-to-follow methods to ripen peppers indoors
All three methods work but also have their pros and cons. I invite you to mail us and let us know which way works for you and your peppers.
1. Ripen peppers in a box or paper bag
Place the picked unripe peppers in a box or paper bag with a ripe tomato or apple. The ethylene produced by the ripe fruit will speed up the ripening process.
We prefer to use cardboard boxes lined with newspaper, but a brown paper bag will work just as well.
Place the box or bag at room temperature, and your peppers should show signs of ripening in a couple of days.
CONS: Peppers go soft before they ripen
2. The windowsill method
Place peppers on a windowsill with good exposure to sunlight. The light and warmth will ripen the fruit, and you should start seeing progress within a few days.
PROS: Easy; fun to follow the progress
CONS: Peppers go soft before they ripen; not practical with more than a handful of peppers
3. Move plant or branch indoors
Moving the plant or a cut-off branch with fruits indoors is a great way to ripen unripe green peppers.
Place the plant at room temperature close to a window with good exposure to natural light. Remove all flowers, buds, and fruits that are too far behind to reasonably have time to ripen.
Use string to hang the cut-off branch and let the peppers ripen naturally on the vine – but indoors.
PROS: This method works best for us
CONS: Requires space, and there is a risk of welcoming insects and bugs indoors
3 essential factors of success in ripening peppers indoors
1. Control the temperature
Place unripe peppers in an environment at room temperature. Too cool, and your peppers will take a long time to ripen, if at all.
2. Place a ripe fruit with your unripe peppers
Placing a ripe fruit with your unripe peppers is a great way to speed up the ripening process. Ripe fruits like apples and tomatoes produce a plant hormone called ethylene that induces your green peppers to ripen.
3. Look for fruits to blush before picking them
Young peppers with a vibrant green color are more difficult to ripen indoors.
When you harvest unripe peppers, look for peppers that have started to blush or show signs of ripening, as they are much easier to ripen successfully indoors.
Windowsill method day by day (with photos)
If you have the option, allow your peppers to ripen on the plant. It is how nature intended, and you will be rewarded with a fuller flavor profile and crispier texture.
But we only have this option for some of our peppers.
We like to grow hot peppers. And they take longer to mature, and sometimes we get a second wave of harvest. It is nearly impossible to ripen all fruits before the weather turns against us.
Below is a day-by-day photo series of Jamaican Bell peppers harvested unripe from one of our plants growing outdoors.
Day 1-2: Placing green unripe Jamaican Bell peppers with ripe Habaneros to induce the ripening process.
Day 3: Getting reason to place all four peppers on the windowsill.
Day 4: 2 out of 4 peppers showing solid signs of ripening.
Day 5: Pepper number 2 also shows clear signs of blushing.
Day 6: The last pepper also shows clear signs of ripening.
Day 7: The last pepper is now also more red than green.
Day 8: All four peppers are almost ripe now.
Day 9: All four Jamaican Bell peppers are ripe and ready “be harvested”.
How do we end up ripening peppers indoors?
A typical growing season looks like this.
- Start seeds in January – February
- Care for pepper seedlings in February, March, and April
- Transplant pepper seedlings outdoors in June
- Harvest peppers from July
- Move plants with unripe fruits into the greenhouse or conservatory when the temperature drops below an average of 50 degrees Fahrenheit / 10 degrees Celsius.
- Harvest as peppers ripen
- Harvest unripe peppers or move plants with unripe green peppers indoors as the temperature drops in the conservatory/greenhouse
Summary: How to ripen green unripe peppers indoors
It is simple to ripen unripe green hot peppers indoors.
But simple does not mean easy. Many things can go wrong, and it is always better to ripen on the vine when possible.
Check on your peppers ripening indoors daily and look for changes in color and texture. If you notice some fruits getting dehydrated or wrinkly, adjust to temperature and light.