Remember how Columbus stepped onto American soil and confidently called Native Americans "Indians"--he was THAT sure he was in India?
Well, that's what he did with peppers too. Capsicum "peppers"--those fleshy hot/sweet fruits--have absolutely nothing to do with the woody Indian vine Piper nigrum and its black peppercorn seeds.
Capsicums are actually in the Solanaceae family, along with deadly nightshade, potatoes, and tobacco. They are native to the Americas--maybe around Bolivia or Brazil originally--and by the time Europeans arrived with their passion for recording history, they had long been scattered by birds and rain rivulets all over MesoAmerica and the Caribbean.
Friedrich von Humboldt, in his Political Essay on the Kingdom of New Spain (1814) noted, "The fruit [of the chile] is as indispensable to the native Peruvians as salt to the whites." The Peruvians, by contrast, came to described the heat of their chiles as gringo huanuchi, or "hot enough to kill a caucasian."
In fact, by the time Europeans arrived in the New World, the 4 or 5 species that are cultivated today--out of a total of some 25 different species--well, they were already cultivated. The ají (see below) were cultivated in Peru as early as 2500 BCE--and it was so important to the descendants of the Incas that the Indian artist who painted the Last Supper for the Caqthedral of Cuzco painted a dish of ajiís on the table for Christ and his disciples.
Not one wild species has since been domesticated, though many are harvested. ALL wild capsicums are pungent. ALL mild and sweet capsicums are that way only because they've been domesticated. But give them one wild summer--or even a boring but hot and dry summer in a city garden--and you've got the pungency back in a New York minute.
What are the 4-5 species? As follows:
Capsicum frutescens (tabasco chiles)
Capsicum chinense (originating in Amazonia, the habanero, datil, and scotch bonnet.)
Capsicum baccatum vas. pendulum (from Peru or Bolivia, ají amarillo)
Capsicum pubescens (from the Andes regions, rocoto)
Capiscum annuum car. annuum (domesticated in Mexico, these constitute the whopping majority--cayenne, bell, poblano, serrano, jalapeno, New Mexican/Anaheim, etc.)
Why are they pungent? It's their amide-type alkaloids (capsaicinoids) with small vanilloid structual components (3 of them) that meet your lips, your tongue, your throat, and plant one hell of a kiss on their pain receptors.
In 1722, Dominican priest Francisco Ximenez commented on a particularly hot habenero, "[This chili is so strong that a single pod would] make a bull unable to eat."
It was in 1912 whilst working for the Parke Davis pharmaceutical company that one of their chemists, Wilbur Scoville, developed a method to measure the heat level of a chile pepper. This test is named after him, it's called the Scoville Organoleptic Test, and it's a dilution-taste procedure. In the original test, Scoville blended pure ground chiles with a sugar-water solution and a panel of testers then sipped the concoctions, in increasingly diluted concentrations, until they reached the point at which the liquid no longer burned the mouth. A number was then assigned to each chile based on how much it needed to be diluted before you could taste no heat.
The pungency of chile peppers is measured in multiples of 100 units, from the bell pepper at zero Scoville units to the incendiary Habanero at 300,000 Scoville units! One part of chile "heat" per 1,000,000 drops of water rates as only 1.5 Scoville Units. The substance that makes a chile so hot (and therefore so enjoyable to Chile-Heads !), is Capsaicin. Pure Capsaicin rates over 15,000,000 Scoville Units !
The validity and accuracy of the Scoville Organoleptic test have been widely criticised. The American Spice Trade Association and the International Organisation for Standardisation have adopted a modified version. The American Society for Testing and Materials is considering other organoleptic tests (the Gillett method) and a number of other chemical tests to assay for capsaicinoids involved in pungency. Even so, the values obtained by these various tests are often related back to Scoville Units. Nowadays the High-Performance Liquid Chromatography (HPLC) test is used. In this procedure, chile pods are dried, then ground. Next, the chemicals responsible for the pungency are extracted, and the extract is injected into the HPLC for analysis. This method is more costly than the previous, but it allows an objective heat analysis. Not only does this method measure the total heat present, but it also allows the amounts of the individual capsaicinoids to be determined. In addition, many samples may be analyzed within a short period.
As a result of all these tests, various varieties of chile peppers can be ranked according to their heat or "pungency" level:
0-100 Scoville Units includes most Bell/Sweet pepper varieties. 500-1000 Scoville Units includes New Mexican peppers. 1,000-1,500 Scoville Units includes Espanola peppers. 1,000-2,000 Scoville Units includes Ancho & Pasilla peppers. 1,000-2,500 Scoville Units includes Cascabel & Cherry peppers. 2,500-5,000 Scoville Units includes Jalapeno & Mirasol peppers. 5,000-15,000 Scoville Units includes Serrano peppers. 15,000-30,000 Scoville Units includes de Arbol peppers. 30,000-50,000 Scoville Units includes Cayenne & Tabasco peppers. 50,000-100,000 Scoville Units includes Chiltepin peppers 100,000-350,000 Scoville Units includes Scotch Bonnet & Thai peppers. 200,000 to 300,000 Scoville Units includes Habanero peppers. Around 16,000,000 Scoville Units is Pure Capsaicin.