The bhut jolokia (Assamese: ভূত-জলকীয়া, Bengali: নাগা মরিচ or বিষ ঝাল), also known as bih jolokia, u-morok, ghost pepper, ghost chili pepper, red naga chili, Naga Jolokia, and ghost chili, is an interspecific hybrid chili pepper cultivated in Bangladesh and Indian states of Assam, Nagaland and Manipur. It is an interspecies hybrid of C. chinense and C. frutescens genes.
In 2007, Guinness World Records certified that the ghost pepper was the world's hottest chili pepper, 900.5 times hotter than Tabasco sauce; the ghost chili is rated at more than 1 million Scoville heat units (SHUs). Classic Tabasco sauce ranges from 2,500 to 5,000 SHUs. However, the bhut jolokia was superseded by the Trinidad moruga scorpion in 2012, which was in turn replaced by the "Carolina Reaper" on December 26, 2013.
The chili is referred to differently in different regions. In Assam, it is widely known as bhot jolokia (ভোট জলকীয়া) or bih jolokia. In some parts of Assam, this chili is called noga jolokia, believed to be named after the ferocious Naga warriors inhabiting the plains and hills of Nagaland. Further complicating matters, a 2009 paper coined the English term "Naga king chili" which refers to the chili's large pod size. This is probably because the chili has long been colloquially known as Raja mircha or Raja mirchi in Nagaland. It also stated that the most common Indian (Assamese) usage is bhot jolokia and gives the alternate common name as bih jolokia (bih means "poison" in Assamese, denoting the plant's heat). The Assamese word jolokia simply means the Capsicum pepper. Other usages on the subcontinent are saga jlokia, Indian mystery chili, and Indian rough chili (after the chili's rough skin). It has also been called the Tezpur chili after the Assamese city of Tezpur. In Manipur, the chili is called umorok or oo-morok (oo = "tree", morok = "chili"). The Kukis called it "Malcha-Phoh" meaning 'the Pungent most chilli'. 
In 2000, India's Defence Research Laboratory (DRL) reported a rating of 855,000 SHUs, and in 2004 a rating of 1,041,427 SHUs was made using HPLC analysis. For comparison, Tabasco red pepper sauce rates at 5000–10,000, and pure capsaicin (the chemical responsible for the pungency of pepper plants) rates at 16,000,000 SHUs.
In 2005, at New Mexico State University Chile Pepper Institute near Las Cruces, New Mexico, Regents Professor Paul Bosland found bhut jolokia grown from seed in southern New Mexico to have a Scoville rating of 1,001,304 SHUs by HPLC.
The effect of climate on the heat of these peppers is dramatic. A 2005 study comparing percentage availability of capsaicin and dihydrocapsaicin in bhut jolokia peppers grown in Tezpur (Assam), showed the heat of the pepper is decreased by over 50% in Gwalior's more arid climate. Elsewhere in India, scientists at Manipur University measured its average Scoville rating by HPLC at only 329,100 SHUs.
Ripe peppers measure 60 to 85 mm (2.4 to 3.3 in) long and 25 to 30 mm (1.0 to 1.2 in) wide with a red, yellow, orange, or chocolate color. The unselected strain of bhut jolokia from India is an extremely variable plant, with a wide range in fruit sizes and fruit production per plant, and offers a huge potential for developing much better strains through selection in the future. Bhut jolokia pods are unique among peppers, with their characteristic shape, and very thin skin. However, the red fruit variety has two different fruit types, the rough, dented fruit and the smooth fruit. The images on this page show the smooth fruit form. The rough fruit plants are taller, with more fragile branches, and the smooth fruit plants yields more fruit, and is a more compact plant with sturdier branches.
Bhut jolokia is used as a food and a spice, as well as a remedy to summer heat. It is used in both fresh and dried forms, to not only "heat up" curries, pickles and chutneys, but also to impart two distinct flavors to them. It is popularly used in combination with pork or dried or fermented fish. In northeastern India, the peppers are smeared on fences or incorporated in smoke bombs as a safety precaution to keep wild elephants at a distance. The pepper's intense heat makes it a fixture in competitive chili pepper eating.
In 2009, scientists at India's Defence Research and Development Organisation announced plans to use the peppers in hand grenades, as a nonlethal way to flush out terrorists from their hideouts and to control rioters. It will also be developed into pepper spray as a self-defence/antirape product.
R. B. Srivastava, the director of the Life Sciences Department at the New Delhi headquarters of India's Defence Research and Development Organisation (who also led a defense research laboratory in Assam), said bhut jolokia-based aerosol sprays could be used as a "safety device", and "civil variants" of chili grenades could be used to control and disperse mobs.
Annually, since 2005, the heat level of Dorset Naga has been tested, taking samples from different sites, various seasons, and states of maturity. The heat level has ranged from 661,451 SHUs for green fruit in 2007, up to 1,032,310 SHUs for ripe fruit harvested in 2009.
High as the results were, the BBC's Gardeners' World television programme recorded a much higher heat level for Dorset Naga. As part of the 2006 programming, the BBC gardening team ran a trial looking at several chili varieties, including Dorset Naga. Heat levels were tested by Warwick HRI, and the Dorset Naga came in at 1,598,227 SHUs, one of the hottest heat levels ever recorded for a chili.
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