The James Crow Chronicles: Part 6 (Crow’s Formulas And Methodologies)

By Chris Middleton / November 26, 2020

Editor’s Note: This is the sixth in a nine part series chronicling the life of James Crow, an extremely important figure in the history of American whiskey. A chemist originally from Scotland, he is credited by some as having invented the sour mash process. Watch this time slot on Thursdays (11am Pacific Time) for the other articles.

Breaking Down Crow’s Methods At The Pepper Distillery

Most of the materials necessary to produce Crow’s sour mash whiskey grew on the Pepper property or were sourced locally from neighboring Glenn’s Creek farms. Only coopers who supplied new white oak barrels were sourced outside of Woodford County. Examining Crow’s key resources and methods for whiskey production starts with the mixed grain recipe.

Agricultural cultivation: Oscar Pepper’s expanding 350-acre farm grew the cereal grains for distilling, as well as selling surplus bushels to local dealers and millers. The most prolific grain was corn, and the most popular varieties in Kentucky accompanied the early settlers from the east coast States in the late 18th century. They crossed Northern flints and south-eastern dents selected to acclimatize to the different growing terroirs in Kentucky.

By the 1830s, the popular varieties were Kentucky gourd seed (Virginia dent), Carolina yellow gourd seed (dent dominant) and red cob white corn (southern dent). Dent corn varieties were easier to mill, and with more oil in the kernel, better suited for fattening livestock, especially in winter when pasture feed was low. The oiliness of many dent varieties proved less popular in Kentucky where distillers developed a preference for varieties of Yellow flint crosses in the early 19th century.

Limestone water has always played a major role in Kentucky distilling (image copyright The Whiskey Wash)

Small grain varieties were winter rye and the popular six-row barley. Both cereal crops harvested in spring were the mash backbone for flavor (rye) and diastatic enzymes (barley). Smaller quantities of wheat were grown for household consumption used for baked goods and bread, and oats also sown in spring for livestock feed. The rhythms of the cereal seasons and synchronized farming activities set in motion the distilling season when the temperature fell.

When the corn crop was harvested, cribbed and shelled, Pepper’s distillery was ready to start mashing from early October and distilled through to early May when the furnace fires extinguished.

Milling & malting: By October 1840, the long drought had broken, and Oscar Pepper’s new distillery and the stone grist mill readied to start production. Imported French or English buhrstones were commonly used by millers until John Tanner, on nearby Grier’s Creek supplied Kentucky’s first local flint millstones from a source of nodular chert on his farm. By adjusting the tension between the millstones, the grinding of corn reduced it to a floury consistency or ‘bruised’ to yield more husk and grits for the rye and malted meal.

Malted barley was essential for delivering amylase enzymes into the mash to produce the diastatic conversion of the starch into sugars. The malting method described at the Pepper distillery was simple and effective. After floor germination in one of the buildings, the sprouted barley dried on a tin sheet heated by the boiler. If the barley was in short supply, Crow malted rye to bolster the ratio to assist the diastatic power.

Limestone water: The water on the Pepper farm filtered through the area’s fine-grained ‘Birdseye’ limestone that gushed from three hillside springs, providing a reliable, uncontaminated, mineral-rich flow of chilled hard water described as ‘clean and sweet’. A pipe mounted on timber trestlework behind the distillery fed the spring water to a stone cistern. The distillery sat on land above the Grassy Springs stream, six hundred yards from where it joined Glenn’s Creek. The farm’s deforested landscape, cleared for fields and pastureland, caused waterway turbidity from the surface water runoff.

The creek’s running water was used for milling and also as a secondary source of cold water to condense the worm in the flake stand. The limited volumes of water from the spring served the modest demands of the distillery at 25 bushels a day. When Gaines, Berry & Company sought to increase the distillery’s daily capacity in the late 1860s, the insufficient volumes of spring water forced them to find another location to build the Old Crow distillery in 1869. Two decades later, Labrot & Graham sunk deep aquifer wells to supplement their water usage to increase their production to 200 bushels a day capacity.

Grain bill: Court testimony decades after Crow died revealed his grain recipe was ‘about 20% small grains’, never less than 20%, indicating the corn ratio was between 75 and 80%. Crow likely changed the proportions marginally by season and by saccharometer assessment. Similar grain formulas were already the orthodoxy for most Kentucky distillers, mashing grain bills of around 80% corn, with 10% rye and 10% malt. Earlier east coast distillers already learnt high corn mashes needed these malt ratios for diastatic conversion and the rye for flavoring.

Mashing, sour mash & fermentation method: Sour mash recipes used by distillers in Kentucky and Tennessee exhibited many variations. Recipe options included varying ratios of scalding water and backset volumes, added at various stages during the grain mashing and to inoculate the fermentation. There is no record of the backset percentages Crow used, as he likely varied the volumes to adjust the pH levels and yeast barm to his daily observations in the mash room. Crow’s adherents working at other distilleries reported they added fresh ‘sweet’ jug or compressed yeast if the ferment became stuck.

Sour mash originally meant no jug or fresh yeast needed adding, this appears to be the case with Crow’s sour mash, where he transferred a portion of yeast foam (barm) from a fermenting batch to help seed or boost propagation to a fresh mash when it was ready for fermentation. Crow employees were particularly secretive about yeasting practice, with most alluding to the absence of fresh yeast under Crow’s method.

Crow made a ‘sour mash hand-made whiskey’ which meant each tub needed stirring by hand. The mash men used wooden rakes, paddles, oars or mash sticks with wooden prongs attached to ‘break-up’ the grain meal to prevent balling and ensure even cooking. Over fifty gallons of water and backset was needed to mash a bushel of grain. As the cooked cereals surrendered their starches, enzymes start breaking it down into sugars for the yeast to convert into alcohol.

Today, modern sour mash distilleries can add commercial enzymes to expedite diastatic conversion and also inoculate the mash with a lactobacillus strain to expedite secondary lacto-fermentation. Crow may have appreciated the nuanced role bacteria played in secondary fermentation, recognizing its contribution to also lower the acidity and add new flavor compounds.

John Hawkins, who worked as a mash man and distiller at Oscar Pepper’s distillery shortly after Crow’s departure reported he used one and a half bushels of grain per tub, indicating larger tubs had replaced some of the bushel sized vessels. One bushel of corn approximated 100 shelled cobs at 56 pounds, producing between 2.3 and 2.7 gallons of spirit in the 1840s, but it also extracted about 24 fluid ounces (700 ml) of oil.

The properties of yeast were a mystery to brewers and distillers until Louis Pasteur began studying yeast from the late 1850s. Pasteur was the first to observe the biochemical formation of amyl alcohol in 1860, the by-product of lactic acid and alcohol, which happens to constitute 60% of the fusel alcohol in American whiskey

The mashing process was simple and repetitive. Corn flour meal was deposited in the tub with boiled water and hot backset from the still at 190F/88C (188F – 198F) and stirred to breakdown the cells walls to release the starch. The mash was left to saccharify for up to 24 hours, sometimes 36 hours, subject to the weather. Setting the mash aside for long hours would start early souring, and form new esters as lactobacillus and wild microbiota began populating the mash, adding orchard and tropical fruit flavor compounds such as ethyl acetates, isoamyl and benzyl acetate. Mashing could take up to a week.

The distillery had over one hundred tubs in various stages of mashing and fermentation; Crow’s mash man was reputed to oversee the filling of up to fifteen tubs daily. After the corn was cooked ground rye meal added at 158F/70C (cooking range 150F to 165F) and stirred with a stick. When it cooled to 142F/61C (135F to 148F) malted barley was stirred in and broken up for about an hour. At 84F to 86F (29C – 30C), conditions were hospitable for the yeast to thrive with fermentation lasting up to 96 hours, sometimes up to five days.

Weather and measurement informed the length of the fermentation. Backset acidified the mash from a pH 5.8 4- to as low as pH 3.2. Devices to measure pH levels were not developed until the 20th century, such as modern litmus paper or the glass electrode, so determining the acidity level was by observation and experienced sensory evaluation. Hawkins revealed another of Crow’s sour mash clues when distilling at Oscar Pepper in the early 1860s, he described after cooling the mash, “put my yeast on it, and set the tub at 84F”. He does not reveal the source of the yeast, whether he inoculated the mash with barm from active fermenters on the floor or another source. As Crow’s original sour mash method allegedly used no fresh yeast culture, it was probably from other active fermenters.

Distillation: Crow rejected ‘log copper beer stills’, the country colloquialism for the triple chambered wooden beer stills with a doubler. He specified the all-copper wash and spirit still, called the singling and doubling stills, direct heat by direct fire – ‘copper fire whiskey’ was another early term used to describe this method. Using two separate distillations, he could separate the heads or foreshots containing methanol, acetone, acetaldehydes in the singling run, and cut the tails or feints from the doubling run, leaving furfurals and fusel alcohols like propanol, butanol, and amyl in the lees.

The distilling vapors had generous copper contact, removing much of the sulphates. A photograph from the early 20th century, taken at the Old Crow distillery, depicts an elementary-type Scottish long-necked still for heightened reflux; positing these latter stills may have been a similar shape to the type of Scottish-style still Crow specified for the Oscar Pepper distillery. He ran his still slow to prevent scalding and to ensure the middle cuts delivered the sweetest, cleanest spirit. Slow running of the stills stopped the still capital being blown off (throwing the head), and excess foam rising through the neck pipe to puke the worm and foul the spirit emptying into the receiver.

By the 1850s, improvements to sour mash fermentation and careful working the still lifted yields from an average 2.5 to 3.5 gallons per bushel. Pepper’s total still capacities remain unknown; however, given the claimed daily mash volumes, low wines (averaging around 50P/25, 22 – 27% ABV) and high wines (over 125P/63%, 58 – 68%), indicates the total stills’ twin capacity at more than 250 gallons. High wines distilled from a copper pot still were commonly diluted to a ‘first class’ proof gallon (100P to 106P/50 to 53% ABV) before barrelling by adding the low wines.

Since March 1791, the Federal Government recognized twelve classes of Dicas hydrometer proofs with differing taxes thresholds, notably for domestic, and duties on foreign imported liquor. By Crow’s time the Tralles 200-point hydrometer was adopted, adding classes of rectified spirits distilled above 75% ABV (135P) as ‘high wines at 6th proof, and alcohol at 95% ABV, e.g. cologne. Crow substituted water instead of low wines, the Scottish practice to minimize the reintroduction of fusel oils and congeners back into the whiskey spirit. Other Kentucky distilleries used the ‘bourbon steam still’ produced a spirit by semi-continuous wooden compartment distillation, that passed through the doubler at a lower proof, not usually needing dilution for barrel entry. Congress decreed in August 1790, the minimum domestic spirit strength as first proof (49.2% ABV), later termed proof gallon and set at 50% ABV. Grain distillers in Britain and America used a variety of treatments to manipulate parts of the whiskey production further.

Crow made ‘straight goods’, called straight whiskey in the 1880s by the Kentucky trade. He did not resort to any artifice or interference such as treating the stills with soap or tallow, adding charcoal finings to the mash or low wines; all common practice in Kentucky and Scotland in the 19th century. Until the late 19th-century, the bulk of American whiskey was further rectified and adulterated. The popular rectification methods used either redistillation to make a purer, higher proof spirit, or employed filtration through charcoal wood or bone char to absorb fusel oils and congeners.

Rectified whiskey or plain spirit was also adulterated before sale by harsh chemicals and flavoring compounds to mask off-notes and imitate the taste of whiskey. By Crow maintaining the highest production standards, his whiskey gained the esteemed reputation in Kentucky as top grade fine whiskey, if not the finest.

Barrel: From the 1830s the customary barrel size contained about 31 gallons, after the Civil War it increased to 40 to 42 gallons, although whiskey barrel capacities varied by cooperage and request, with the Government reporting and the trade transacting in the most common barrel capacities. Spirit whiskey entered into the barrel first proof strength or 100 Proof, or few degrees above. Barrels were commonly charred as it was discovered to be an effective method to reduce the fusel alcohols. Fusel alcohols and congeners that spent longer time oxidizing and interacting with the barrel wood also transmuted into desirable new flavour compounds. Flavors that gave whiskey its wholesome, distinctive and palatable characteristics.

Whiskey described as ‘old’, was usually two to three years in wood. Crow specified storage at a minimum three to four years for the whiskey to begin to ‘ripen’; Between 1817 and 1862, the Government legislated no excise taxes on production or penalties caused by outages, such as annual evaporation and leakage, so aging incurred no financial penalties from authorities. Whiskey was aged for as long as distiller or dealer thought it financially advantageous. Pepper and Crow barrels were stored in a cool limestone warehouse adjunct to the still house where ventilation prevented mustiness, and in winter the warehouse was heat controlled by piped hot water to moderate the ambient temperature, another innovation credited to Crow.

Ten years after Crow left the Pepper distillery, and three months after the Confederacy surrendered in April, Oscar Pepper died June 1865. His probate estate catalogued his equipment and assets. The outbuildings held 400 barrels of corn (2,000 bushels), 400 bushels of rye, 30 bushels of malt and 120 gallons of cellared whiskey, plus copper stills and a boiler. The register recorded eleven females and twelve male slaves.

A few months later, Congress passed the 13th Constitutional Amendment abolishing slavery in December 1865. Kentucky did not secede from the Union, remaining neutral during the War. In February 1865, both Kentucky State Houses overwhelmingly rejected the 13th Amendment; they did not ratify the 13th Amendment until March 1976. Also catalogued, the farm grew to 829 acres with 21 horses, 7 mules, 25 dairy cows, 30 yearlings and steers, 56 sheep and over 100 hogs. The cellar noted one eleven-year-old barrel, whiskey made by Crow before he left the Pepper distillery.

In part 7 next week we take a look at Crow’s distilling team and production volumes.