"Oh my gosh, that is so hot."

"This is not hot, it's medium at best."

How many times have you heard someone say that? The truth is that people have different tolerances and judgments about the heat of their food as much as one person liking one dish and another hating it. It's all about individual taste, and tolerance.

Capsaicin, an irritant, is an active component found in chili peppers. It was first extracted in 1816 by Christian Bucholz and then later refined through the years including a pure crystalline form in 1876 by John Thresh who gave it today's spelling "capsaicin" as we know it. In 1961 two Japanese chemists, S. Kosuge and Y. Inagaki, isolated similar substances from the chili peppers and called them capsaicinoids.

In capsaicinoids, there are two main compounds: capsaicin and dihydrocapsaicin.

To understand the heat level involved in these two compounds, we must first understand the Scoville Heat Scale. The scale for measuring the heat of food was created by Wilber Scoville in 1912 while employed at Parke-Davis pharmaceutical company to measure "hotness" of various chili peppers.

In Scoville's method, an extract of the capsaicin oil from an exact measured amount of dried pepper is joined with incremental amounts of sugar-water until the "heat" is no longer detectable by a team of up to five tasters. The amount of sugar-water added to the extract until the heat is diluted becomes the measure on the Scoville scale. The weak spot of this test is that it is dependent on the personal taste and tolerances of the testers, who were only allowed to test one sample per session. How would you like that job? As unscientific as this seems, in 1922, Scoville won the Ebert prize from the American Pharmaceutical Association for the best report of original investigation of a medicinal substance.

Starting at zero on the Scoville heat scale is the bell pepper with virtually no heat, followed by the Poblano pepper at 500-2500, Jalapeno pepper at 2500-8000, Cayenne at between 30,000-50,000, and all the way up to Naga Jolokia pepper rated at 855,000-1,075,000. The variance in the numbers for each pepper can be influenced by numerous factors such as seed lineage, the soil they are grown in, and the climate. Of the two main compounds mentioned earlier: capsaicin is between 15 million and 16 million, and dihydrocapsaicin is a cool 16 million.

So why is it that we have different perceptions of the sense of heat?

Sensory receptors in the body vary for different reasons. The chemosensory system, which transmits the signals, can be influenced by factors such as: smoker/non-smokers, colds or allergies, age, head injuries, dry mouth, medications, and history or familiarity of eating hot or spicy foods. When you are born you are fortunate to have 10,000 taste buds... but you are eating baby food. Between the ages of 40-50, the number of receptors on your taste buds start to dim and decrease.

But taste buds are not the main player here... it is another chemosensory mechanism that involves thousands of nerve endings on the moist surfaces in your mouth, and throat. These nerve endings sort out the temperature between the sensation of ice cream and the fiery taste of chili peppers.

In families where hot or spicy food is a mainstay, you will often see a high tolerance to high heat where others would scream at the intensity. Eating hot or spicy foods can increase your tolerance and decrease your sensitivity over time. Consider the countries of India, Mexico, Vietnam, Thailand, China, Jamaica, Singapore, Trinidad, Korea and many others who were raised on hot and spicy foods. Their version of medium would be your version of flaming hot.

One last bit of advice for those who like to find their tolerance of heat... Never try to soothe a flaming mouth with water... it only makes it worse. Too many people make that mistake. Both milk and yogurt contain lactic acid that can dissolve the effects of capsaicin. But somehow I can't picture that guy in the sports bar with his chicken wings doused in Volcano III hot sauce asking for a glass of milk.