How we verify heat

Every pepper in Capsi shows a Scoville figure — but heat is trickier, and more interesting, than a single number suggests. Here's what Scoville actually measures, why you'll see a range instead of one number, and how we decide which numbers to trust.

What Scoville measures

The Scoville scale rates a pepper's pungency in Scoville Heat Units (SHU). It was devised in 1912 by pharmacist Wilbur Scoville, who diluted pepper extract in sugar water until a panel of tasters could no longer detect the burn — the more dilution needed, the higher the SHU. That original "taste panel" method is subjective, so modern labs instead use high-performance liquid chromatography (HPLC), which measures the actual capsaicinoid compounds in the fruit and converts them to an SHU-equivalent. Higher SHU means more capsaicin, and more heat.

Why heat is a range, not one number

The same variety can measure wildly differently from one fruit to the next. Heat depends on:

• Genetics — even within a variety, seed lines drift. • Ripeness — capsaicin climbs as a pod matures. • Growing conditions — heat, drought stress, and soil all push SHU up or down.

So a lab testing a dozen Carolina Reapers might find anything from ~1,000,000 to ~1,600,000 SHU across the batch. A single "1,400,000 SHU" tells you less than the honest span. That's why we lead with a range, and only show a "typical" figure when a study actually reports one — never an average we invented.

The problem with most pepper numbers

Here's the uncomfortable part: a lot of the Scoville figures you'll find online are unverified, repeated, or inflated. Seed sellers and sauce makers have an incentive to claim the biggest number — "world's hottest" sells — and once an inflated figure is published, other sites, databases, and AI tools copy it until it looks like established fact. Very few sources cite an actual lab test.

We didn't want Capsi to be another link in that chain.

How Capsi sources heat data

Every heat figure in Capsi is tied to a source, and every source carries a trust tier so you can see at a glance how much weight it deserves:

• Lab-verified Measured directly using HPLC lab analysis and published in a peer-reviewed scientific journal. This is the gold standard — it includes a real DOI so you can read the full study yourself.

• Official breeder Directly stated by the breeder, cultivar registrar, or a university/government institution that developed or officially tested the variety. These come from the people actually responsible for the pepper.

• Referenced From a credible reference, database, or catalog that clearly explains its own testing methodology or primary lab work — not just repeating someone else’s number.

• Vendor Claim A number provided by seed sellers, sauce companies, or commercial growers in their product listings. Heat claims in marketing can be higher than actual typical measurements, so we display them separately and label them clearly.

• Unverified Numbers repeated across websites, lists, wikis, or AI summaries with no traceable primary source or lab test. This is the most common (and least reliable) data on the internet — Capsi never uses it for headline figures.

A single pepper can carry several at once — a lab study and a vendor claim — and we show them all, strongest first. The badge on the headline always reflects the best available evidence, and the headline range is drawn only from that best tier. So a vendor's inflated high can never stretch a "Lab-verified" range or borrow its credibility — you'll still see the vendor's number in the sources list below, where you can judge it for yourself.

Why we stop at Lab-verified

Could we demand even more? In pure scientific terms, yes. Multiple independent labs confirming the same numbers, genetic verification of the exact cultivar, multi-year multi-location trials, and fully open raw data would all be stronger evidence.

We deliberately stop short of that. High-quality peer-reviewed HPLC studies are already uncommon. Most of the thousands of pepper cultivars have never been formally lab-tested in a journal at all. Raising the bar higher would leave nearly every variety showing “Heat not yet documented.”

A single peer-reviewed HPLC analysis with a real DOI is therefore the practical high bar we chose. It is rigorous enough to filter out marketing claims and unverified numbers, while still allowing usable data for the varieties that do have solid published work.

For the hardcore enthusiasts who want to dig deeper, that DOI is an excellent starting point. We stop here so the data stays both honest and useful.

When there's no good data

Most of the thousands of pepper cultivars have never been formally lab-tested — that's normal, not a red flag on any one pepper. When a variety has only a vendor or unverified figure, we say so plainly: "No lab study has been published for this variety yet." And when there's no reliable measurement at all, we show "Heat not yet documented" rather than invent a number. We'd rather tell you we don't know than pretend we do.

From number to category

Every documented pepper also carries one of five heat categories — Sweet, Mild, Medium, Hot, Superhot — and these are never a judgment call. The category is derived mechanically from the pepper's typical SHU, using the same boundaries the heat scale on every pepper page draws:

• Sweet — under 100 SHU (bell-pepper territory: no real heat) • Mild — 100 to 2,500 SHU • Medium — 2,500 to 30,000 SHU (jalapeño and serrano territory) • Hot — 30,000 to 350,000 SHU (cayenne through habanero) • Superhot — 350,000 SHU and up (Red Savina, ghost pepper, Carolina Reaper class)

There's no universal standard for these names, but the anchors above match how growers and chileheads actually use them — including reserving "superhot" for the class beyond habanero. Because the category comes straight from the measured number, the label, the scale, and the marker you see on a pepper's page always agree.

Reading a pepper's heat

When you tap the ⓘ on any pepper's Scoville number, you'll see:

• The documented range — the honest span, from the most trustworthy source available. • A verification badge — how much to trust it, at a glance. • A "typically" figure — a single value to anchor on, but only when a credible source reports one. • The sources — the actual studies and references, tappable, strongest first.

That's the whole idea: not a prettier list of marketing numbers, but the most honest, checkable heat data we can give you.