Peppermint and spearmint plants are commercially cultivated for their oils, which are primarily used to flavor candy and chewing gum, cough drops, and toothpaste. Originally cultivated and harvested by hand in small plantings of 10 acres or less and crudely distilled, Washington's mint now comes from large modern mechanized farms producing high crop yields and oils of exceptional quality relative to cost. Most of the state's mint farms are located in Adams, Grant, and Yakima counties. As of 2017, Washington produced 2,100,000 pounds of spearmint oil and 1,440,000 pounds of peppermint oil, making it the nation's leading spearmint-oil producer, and the third-highest peppermint-oil producer.
Scotch spearmint (Mentha spicata) is named for its spear-like flower spires. Spearmint, which does not contain menthol, was grown in Europe beginning in about the ninth century B.C. Since the early twentieth century, its oil has primarily been used to flavor toothpaste.
Peppermint (Mentha x piperita) is a natural hybrid of spearmint and water mint (Mentha aquatica). It was discovered growing in a garden in Hertfordshire, England, in 1696. Peppermint, which contains menthol, is named for its peppery flavor.
Peppermint and spearmint oils are volatile (also called essential or ethereal) oils. Volatile oils are composed almost entirely of hydrocarbon compounds called terpenes. Menthol is the major terpene found in peppermint oil, while carvone is the major terpene found in spearmint oil. Both plants are highly aromatic.
Mint is mentioned twice in the New Testament of the Bible, and mint-oil distillation was described in literature as early as 410 A.D., according to American Essence, a 1969 history of mint oil. The Romans are believed to have brought spearmint to Britain, and it was common in gardens by medieval times. By 1750, peppermint and spearmint oil were under commercial cultivation in England. Mint cultivation spread to the Netherlands in 1770, and to France and Germany soon after.
Mint on the March
Mint reached the United States before 1800, most likely brought as root stock by European colonists, who found that it flourished near streams and on swampland. Peppermint was commercially cultivated for distillation in Massachusetts by the 1790s, and slightly later in northern New York and New Jersey. Much of the oil these operations yielded was peddled door to door. Mint growing had spread to Ohio by 1833 and to Michigan a few years later.
By the mid-1850s, America's mint industry was centered in Wayne County, New York, headquarters of the W. B. Hotchkiss Company. Hotchkiss exported mint oils to Europe and entered his product in major expositions, winning prizes and building his product's fine reputation. The Michigan-based A. M. Todd Company did likewise. In Michigan and Indiana, mint was cultivated in so-called mucklands -- highly organic silty soils that were a byproduct of retreating Ice Age glaciers.
Washington Welcomes Mint
In 1903, Oliver H. Todd (1848-1930), brother of A. M. (Albert) Todd (1850-1931) and former partner in the A. M. Todd Company, introduced commercial peppermint to Idaho and, in 1909, to Oregon's Willamette River Valley. In 1917, Todd planted commercial peppermint on drained land on Puget Island in the Columbia River estuary in Wahkiakum County.
In 1926, Oregon mint grower W. J. Turnidge (1867-?) oversaw experimental peppermint plantings near Sunnyside, Kennewick, Richland, and Walulla in Central Washington. The crop flourished. Mint-oil prices were high at the time, and more farmers in the state began growing mint.
By 1927, Washington's peppermint farms were mainly located along the lower Columbia River, in the Puget Sound region between Tacoma and Burlington, and in the lower Yakima Valley. By 1929, Washington had 846 acres of peppermint, grown by 113 farms, producing 28,732 pounds of oil.
Mint Planting, Harvesting, and Oil Production
Mint is cultivated by root stock. Mint plants require copious water supply, either in the form of wet soil or -- as in Washington -- via irrigated fields. Mint needs long sunny days and cool nights in order to flourish. Dry climate, such as that found in Washington's prime mint-growing regions, helps ward off leaf diseases. Weed control is important, since any weeds harvested with the mint will negatively affect the flavor of the oil.
In order to obtain the maximum amount of oil, mint is harvested when the plants are in bloom. The plant's oil glands are found on the underside of the leaf. Different regions and even different microclimates produce oil with different flavor characteristics. In modern production, these flavor qualities are carefully analyzed and custom-mixed to suit the exact requirements of commercial customers, who demand consistent flavor for their products.
Mint is harvested by mowing. The resultant mint hay is racked into rows in the field to dry for several days. These heaps are then hauled to the distillery, originally by wagon and now by truck. Each mint farm has its own distillery. In general, mint oil is distilled from mint hay on the farm, using the steam method of distillation. Mint oil is then separated off. Before use, the oil is redistilled in order to purify it further.
During the 1920s, American manufacturers of candy, chewing gum, and toothpaste mounted major advertising campaigns for their products, many of which were flavored with mint. The growth of this sector opened a new domestic market for peppermint and spearmint oils, although much of the product was still exported.
Mint exports increased during the 1930s, but distribution stalled during the buildup to America's entry into World War II. Mint exports to Germany ceased in 1940. In 1941, shipments to France and the Netherlands were discontinued, and demand in Great Britain slowed.
The war also halted import of Japanese products. Prior to the bombing of Pearl Harbor and America's entry into the war, Japanese mint oil (Mentha arvensis L.) was the leading source of menthol used in American products such as cough drops, chest rubs, and cigarettes. After Pearl Harbor, menthol was extracted from American-grown peppermint. High demand for candy and chewing gum to supply the armed forces led to the classification of spearmint and peppermint as essential war crops.
Washington's peppermint acreage expanded during World War II, from 1,800 acres in 1941 to 4,200 acres in 1946. Irrigated Yakima Valley farmlands accounted for 75 percent of this growth. Richland growers, their land preempted by the federal government for the Hanford Project, harvested their final crop in 1944. Many of these growers relocated to the Yakima Valley and Kennewick areas. The opening of the Roza Canal in 1944 supplied water to lands at higher elevation. By 1949, 300 of Washington's 349 mint farms were near Yakima and Kennewick.
Washington Takes Lead in Mint Production
By 1946, Washington and Oregon produced nearly half of the nation's mint-oil supply. Chlorophyll toothpastes, flavored by spearmint oil, were introduced in 1947. Demand for the oil surged, stimulating increased planting. Chlorophyll was marketed as a help in eliminating bad breath.
During this period the I. P. Callison Company, based in Lacey in Thurston County near Olympia, emerged as a leading mint-oil distributor, first in the United States and eventually on the world market. Israel Putnam Callison (1870-1961) was a former Chehalis schoolteacher and, later, newspaper publisher who in the early twentieth century turned to the distribution of wild plants and, eventually, mint oil.
The Callison Company used the marketing slogan "The finest peppermint oil comes from the Pacific Northwest." The firm promoted western oils throughout the country, greatly aiding the global acceptance rate for Washington's peppermint oil. In 1946, I. P. Callison planted 160 acres of Scotch spearmint near Sunnyside. In 1947, his son Henry Callison (1898-1994) took over this project, before eventually striking out on his own. Within a decade of that first planting, Washington was the nation's top spearmint producer.
By 1950, mint growers in Michigan and Indiana -- plagued by Verticillium wilt, a plant pathogen that kills plants and contaminates the soil for several years thereafter -- turned to other crops, to the benefit of Pacific Northwest growers. The mint industry in Washington and Oregon developed in step with increasingly sophisticated mechanical planting and harvesting equipment, and with modern distillation units, another boon to the industry. In 1955, Washington led the country in the production of mint oils.
In 1957, Henry Callison introduced native spearmint (Mentha cardiac), which is stronger-tasting than Scotch spearmint, into another mint operation in Yakima, using roots grown in Indiana. Unlike Scotch spearmint and peppermint, native spearmint is resistant to Verticillium wilt. Demand for both types of spearmint oil has historically been high. By 1967, nearly 15,000 acres of spearmint were under cultivation in the Yakima Valley, 6,000 of those planted with the native variety.
By the mid-1960s, most mint production in the Puget Sound lowlands and near the Canadian border had ceased. Production in the lower Columbia River area, plagued by mint-rust, a fungal disease, had also mainly ceased. The lower Yakima Valley between Union Gap and Benton City, and the vicinities of Kennewick and Pasco, produced the bulk of Washington's mint, making the Yakima Valley the most important mint-producing region in the history of America's mint industry. In the Columbia Basin, Othello mint farms made the town and vicinity second only to the Yakima Valley in terms of mint production.
From Field to Mouth
Once harvested, mint goes through several steps before reaching the consumer. Mint growers sell distilled mint oil to a dealer/broker. The dealer/broker evaluates and further refines and blends mint oils to clients' exact specifications. The dealer/broker sells this custom-blended oil to manufacturers, or stores the oil for future sale. Manufacturers flavor products with the oil, then sell the finished products to consumers.
Mint oil is so highly concentrated that a single drop can flavor a tube of toothpaste. Growers store mint oil in 55-gallon drums. A 2012 article in the Tri-City Herald quoted Washington Mint Commission executive director Rod Christensen stating that the oil in one drum could flavor five million sticks of chewing gum.
Spearmint oil is one of the few natural flavorings for which no acceptable artificial substitute exists. This made the price the oil could command volatile. In 1976, spearmint oil fetched $20 per pound. By 1978, its price had plummeted to $2 per pound.
In 1979, under the oversight of the federal government, about 250 western mint growers organized Far West Spearmint Marketing, a group that controls the flow of mint oil into the market in order to stabilize prices. Production levels are established a year in advance, dependent on worldwide demand. Only farmers in the Far West group are eligible to receive production allotments. Buyers will not purchase oil from farmers who do not hold an allotment. This practice keeps prices stable and assures that all spearmint oil produced will have a market.
Mint Processing and Production Today
Labbeemint, founded in 1971 by peppermint farmer Jack Vernon Labbee (1917-2017) and based in White Swan in Yakima County, is a global supplier of peppermint and spearmint oil. Labbeemint offers these oils to manufactures in both natural and redistilled forms. Mint oils produced by Labbeemint scent and flavor air fresheners, candles, hair and skincare products, essential oils, soap, tobacco, food and beverages, and nutritional and pharmaceutical products, according to the ThomasNet industrial-marketing website.
Callisons, as the I. P. Callison Company was renamed, works with mint growers worldwide. In addition to mint-processing facilities in Chehalis and Lacey, the company maintains a plant in Indiana and (as of 2017) in China. In 2014, Callisons developed mint-flavor crystals that are longer-lasting and more flavorful than mint oil, according to the company's website.
The year 1997 marked the peak of mint-oil production in the United States. Central Washington was the largest producer of spearmint in the world, particularly of native spearmint, of which the state produced up to 98 percent.
More recently, the American mint industry, including Washington farmers, has faced growing competition from China and India. Although consumers' appetite for mint-flavored products continues to increase worldwide, their taste has shifted toward bolder mint flavors. Imported mint oil is less expensive and can supply these more aggressive flavor profiles when blended with the more-expensive domestic product.