Chilli and Pepper Heat Scale (Scoville)

How hot is a jalapeno? Use the interactive heat picker to compare 22 real chillies and capsicums, from sweet to superhot

Every chilli has a number. From a sweet capsicum that registers zero to a Carolina Reaper that tops two million, the Scoville scale puts the heat of a chilli into a figure you can compare. This guide explains what that number means, lets you sort and filter 22 real varieties by heat in the picker below, and shows how to grow chillies that deliver on both flavour and fire.

What the Scoville Scale Is

The Scoville scale measures how hot a chilli is, in Scoville Heat Units (SHU). It was created in 1912 by pharmacist Wilbur Scoville, who diluted chilli extract in sugar water until a panel of tasters could no longer detect the burn. The more dilution it took, the higher the score. Today the capsaicin content is measured precisely in a lab, then expressed in the same SHU units, so the scale has stuck.

The heat itself comes from a group of compounds called capsaicinoids, the main one being capsaicin. Capsaicin is concentrated in the white pith (the placenta) that holds the seeds, not in the flesh and not really in the seeds themselves. That is why removing the pith and seeds takes a lot of the heat out of a chilli. Capsaicin does not cause real tissue damage. It triggers the same nerve receptors that respond to actual heat, which is why your mouth feels like it is burning when nothing is.

One thing the number does not tell you is how a single plant will turn out. The same variety can land anywhere within its range depending on how it was grown. Heat, full sun, and a bit of water stress all push a chilli toward the hot end of its band, while a cool season and plenty of water keep it milder. The grower has real influence here, which is the fun of it.

The Interactive Heat Picker

Here are 22 chillies and capsicums you can actually grow, sorted from sweet to superhot. Filter by heat band or click a column heading to sort. The SHU figures are typical ranges; your own fruit may land higher or lower depending on the season and how you grow it.

No chillies match that heat band.

How to Grow Chillies for Flavour and Heat

Chillies are a warm-season crop and they love it hot. Get the basics right and you will pull fruit off the plants for months.

• Warmth and full sun. Chillies need a long, warm season and at least 6 to 8 hours of direct sun. They sulk in cold soil, so do not rush them out in spring. Warm conditions are also what drive capsaicin, so a hot, sunny spot gives you both a bigger crop and a hotter one.
• Start early. Sow seed indoors 8 to 10 weeks before your last frost, on a warm windowsill or heat mat. Chilli seed is slow and needs warmth (around 25 to 30 degrees Celsius) to germinate. Superhots are slowest of all, so start them earliest.
• Feeding. Dig compost into the bed before planting. Once the plant starts flowering and setting fruit, switch to a potassium-rich feed (a tomato or flowering-plant fertiliser is ideal). Go easy on nitrogen once flowering starts, or you will get a big leafy bush and little fruit. Comfrey tea is a great free, high-potassium feed.
• Stress for heat. Capsaicin is the plant's stress response, so a little hardship raises the heat. Once the fruit has set, ease back on watering and let the plants run slightly dry between drinks. Do not starve them completely, just keep them on the lean side. Hot, dry, sunny conditions produce the fieriest chillies.
• Let them ripen. A green chilli is unripe. As it ripens to red, orange or yellow it gets both sweeter and hotter and develops a fuller flavour. Picking green keeps the plant cropping; leaving fruit to colour up gives you the most heat and sweetness.

Handling and Using Chillies

Capsaicin is potent stuff, and the hotter the chilli the more care it needs.

• Wear gloves for hot types. When prepping anything from habanero up, wear disposable gloves. Capsaicin clings to skin and you will transfer it to your eyes, lips and anywhere else for hours, no matter how well you wash. Keep your hands away from your face while you work.
• Milk, not water, for the burn. If a chilli is too hot, reach for milk, yoghurt or something fatty. Capsaicin dissolves in fat and milk proteins, not in water, so water just spreads the heat around. The same goes for your hands and mouth.
• Drying and storing. Thin-walled chillies like cayenne and bird's eye dry beautifully. Thread them on string and hang them somewhere warm and airy, or use a dehydrator on low. Once they are crisp and snap cleanly, they will keep for a year or more in an airtight jar.
• Flakes and powder. Blitz dried chillies into flakes or a fine powder in a spice grinder. Do it in a ventilated spot, as the dust will catch in your throat. Homemade chilli powder is worlds ahead of anything in a supermarket jar.
• Fermenting hot sauce. A glut of ripe chillies turns into a brilliant fermented hot sauce. Pack them in a salt brine, let them ferment for a couple of weeks, then blend and bottle. See our preserving the harvest hub for the method, along with drying, freezing and bottling.

When to Grow Chillies in Australia

Chillies are frost-tender and need warmth, so timing is everything. Across most of Australia, start seed indoors in late winter to early spring, then plant out only once the soil has warmed and all frost has passed.

• Cool-temperate (Melbourne, Hobart, Canberra). Start seed indoors in August, plant out from late October once nights are reliably warm. The season is short, so favour faster chillies and grow superhots in pots you can move and protect.
• Warm-temperate and subtropical (Sydney, Brisbane, Perth). Sow from late winter and plant out through spring. A long warm season here suits even the slow superhots in the ground.
• Tropical (Darwin, Far North QLD). Grow through the dry season. Chillies are often perennial here and will crop for several years if frost-free.

Plan Your Chillies in the App

The heat picker above helps you decide which chilli to grow. The Planting Season app helps you grow it. When you add a chilli to your garden you choose the variety from the in-app dropdown, from a sweet capsicum to a Carolina Reaper, and the app tracks it from sowing through to harvest with reminders tuned to your region. Grow a jalapeno for everyday cooking, a cayenne for drying and a superhot for sauce, and keep them all on one plan.

Frequently Asked Questions

See also: How to Grow Chilli and How to Grow Capsicum