When serrano peppers turn from green to red, it signals that the pepper is fully ripe and at peak flavor. This color change is completely natural for serrano peppers and occurs as they mature on the plant. While green serranos pack a punch, red serranos tend to be even hotter and more flavorful. Read on to learn more about what happens when serranos turn red and how it affects their taste, heat level and uses.
Why Do Serrano Peppers Turn Red?
All peppers, including serranos, start out green when they first form on the plant. At this immature stage, the pepper contains chlorophyll, the green pigment responsible for photosynthesis. As the pepper continues to ripen, chlorophyll breaks down and carotenoids become more prominent. Carotenoids are the red, orange and yellow plant pigments responsible for the color in tomatoes, carrots, and of course, red peppers.
The most prevalent carotenoid in red peppers is capsanthin. As chlorophyll degrades, capsanthin accumulates and masks the remaining green pigment, causing the pepper skin to turn fiery red. This color change signals the pepper is fully mature and ready for picking.
Red Serrano Heat Level
Red serrano peppers register a Scoville heat level of 10,000 to 25,000 SHU on average. By comparison, green serranos range from 5,000 to 17,000 SHU. So while the heat intensity can vary quite a bit depending on individual peppers, most people perceive red serranos as hotter than green.
The increase in heat as serranos ripen can be attributed to two factors:
- Higher capsacinoid levels – Capsaicin and other capsinoids are the chemical compounds that give chili peppers their spicy kick. As serranos transition from green to red, they produce more of these heat-producing chemicals.
- Loss of water content – Mature red peppers are drier than their unripe green counterparts. Since capsaicinoids are concentrated in the flesh, the loss of moisture makes the remaining heat compounds more concentrated and pronounced.
So essentially, as serranos ripen their moisture content decreases, while their capsacinoid content increases. Both factors contribute to red serranos packing more heat than green ones.
Flavors and Uses
In addition to increased spiciness, red serrano peppers take on new depths of flavor. The ripening process builds up sugars in the flesh, making red serranos taste sweeter and more complex than green ones. Descriptors like “fruity,” “smoky,” and “nutty” are often used for the flavor of red serranos.
Red serranos can be used similarly to green ones in recipes where spicy heat is desired. Their riper flavor profile also makes them ideal for use in salsas, sauces, marinades, spice rubs, and anywhere their rich flavors can shine. Try using red serranos in the following ways:
- Chopped fresh in pico de gallo or salsa
- Added to chili, stews and curries
- Pickled or roasted for unique condiments
- Pureed into hot sauce or harissa paste
- Infused into vinegar or oil
- Dehydrated and ground into flakes or powder
When cooking with red serranos, be mindful of their higher heat level compared to green. Start with a smaller amount and adjust upwards according to your spice tolerance.
Growing Red Serrano Peppers
While you can find red serrano peppers at many grocery stores, you may get the best quality peppers from your own garden. Growing your own serrano plants allows you to control conditions and pick the peppers at optimal ripeness.
Here are some tips for growing red serranos:
- Start with transplants – Serrano peppers grown from seed take quite a while to mature peppers. Starting with transplants gives them a head start.
- Choose full sun – Serranos need at least 6-8 hours of direct sunlight per day.
- Use warm soil – Wait to plant until soil temperatures reach at least 65°F.
- Give space – Allow 18-24 inches between plants.
- Provide support – Use cages, stakes or trellises to support the bushy plants.
- Water carefully – Serranos are drought-tolerant but need regular water, about 1-2 inches per week.
- Fertilize lightly – Use a balanced fertilizer at planting and half-rate every 4-6 weeks.
- Harvest ripe peppers – Allow peppers to turn fully red on the plant for peak flavor and heat.
With excellent growing conditions, serrano plants can produce peppers all season long. Pick red serranos promptly at maturity for the best quality.
Storing Red Serrano Peppers
Red serrano peppers will last 1-2 weeks when stored properly. Follow these tips to maintain freshness:
- Refrigerate in a perforated plastic bag – Leave space for air circulation but contain any moisture lost.
- Store at high humidity – The crisper drawer works great.
- Keep stems intact – Leave the stems on to prevent moisture loss.
- Refrain from washing until ready to use – Moisture speeds up spoilage.
Properly stored, red serrano peppers will retain their signature heat and flavor for up to 2 weeks. Beyond that, they may begin to shrivel or mold. For long term use, consider methods like freezing, pickling, or drying.
Pickled Red Serranos
Pickling is a popular preservation method that allows you to enjoy red serranos year-round. The vinegar brine soaks into the flesh for a tangy, spicy flavor. Try this easy refrigerator pickle recipe:
- 1 pound red serrano peppers, stems removed, sliced into rings
- 1 cup white vinegar
- 1 cup water
- 2 cloves garlic, peeled and halved
- 1 tablespoon kosher salt
- 1 teaspoon sugar
- 1 bay leaf
- Slice serranos into thin rings and pack tightly into a clean glass jar.
- Bring vinegar, water, garlic, salt, sugar and bay leaf to a boil. Stir to dissolve salt and sugar.
- Pour hot brine over the serranos to cover. Allow to cool to room temperature.
- Refrigerate for at least 48 hours before serving to allow flavors to meld.
- Store pickled peppers in the fridge up to 2 months.
These easy refrigerator pickles are tangy, spicy and delightfully crunchy. Use them anywhere you would enjoy pickled peppers. The red serranos add festive color and great flavor.
Drying Red Serranos
Drying concentrates the compounds that give red serranos their heat, making dried flakes and powder an extremely spicy seasoning. Here is a simple dehydrator method:
- Red serrano peppers, washed and stems removed
- Cut peppers in consistent, uniform size. Rings or small pieces work well.
- Arrange in a single layer on dehydrator trays without overlapping.
- Dehydrate at 125°F until completely dried and brittle, about 6-10 hours.
- Cool and store in an airtight container up to 1 year.
- Grind into flakes or powder as desired.
Home dried red serranos make a spicy addition to chilis, stews, salsa and anywhere you want a blast of heat and fruity pepper flavor. Start with a small amount and adjust to your preferred spice level.
Freezing Chopped Red Serranos
Freezing is another way to preserve fresh red serranos for extended use. Try this chopped preparation:
- Red serrano peppers, washed, stemmed and chopped
- Chop or slice serranos, discarding stems.
- Spread pieces in a single layer on a parchment-lined baking sheet.
- Freeze until solid, about 2 hours.
- Transfer to freezer bags or containers, removing as much air as possible.
- Freeze up to 10 months.
Chopped frozen serranos are perfect for cooking applications like chili, salsa, curry and stir fries. Their ice crystals break down easily into dishes. Just substitute equivalent amounts of thawed chopped peppers in your favorite recipes.
Allowing serrano peppers to fully ripen to red on the plant results in their signature intense, fruity heat profile. Red serranos take on more sweetness and complexity compared to their green counterparts. Use their bright spiciness to add punch to any dish. Preserve the quality and heat of your harvest with quick pickling, drying or freezing. With proper harvesting and storage techniques, you can enjoy flavorful red serranos year-round.