Calvert Distillery’s Baltimore Rye Whiskey, 1936

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“With the Institute at the World’s Largest Rye Distillery”—Chemical and Metallurgical Engineering, November, 1936

It is post prohibition and we are at the world’s largest rye distillery in Baltimore Maryland! There is a three chambered still erected after prohibition. However, this distillery will be converted to industrial ethanol for the war in 1942 so there is just a few years of glorious operation.

They are distilling 85% Rye with 15% malt. Much of that rye isn’t even American and comes from Poland or Latvia due to quality constraints. Some of the malt in their yeast mash is even rye malt!

Their three chambered still collects no hearts and is merely high wines & low wines of which the high wines are rectified on a pot still. Their batch doubler (the pot still) generates whiskey between 112-115 proof and it hits a bonded warehouse at 103 proof!

Calvert, who knew? But the war would come and erase it all.

There is a chance this whiskey was consolidated to mash bills 3f & 3h in the 1967 IRS survey. If that is the case, distillation proof and entry proof were increased, but fermentation duration was also increased. It is not clear if a three chambered still was in operation in the 1960’s. I don’t think it is know when the last three chambered still was in operation. I remember hearing somewhere it was believed they did not survive prohibition but we see one in operation here.

Another description of the Calvert facility pops up in 1939. Plant Control of the Engineering Operation at the Calvert Distilleries, Relay, Maryland (shared with me by a friend of the blog). This telling by John C. Marzolf was written for initiation into Phi Mu, an engineering honor society. There is no mention of a three chambered still, possibly because of a different focus for the limited space. There is mention of a “lactic sour” being produced. It is 1939 and they are measuring pH! Their rye mash is about 5.5 at conversion.

[There are other great crisp photos in the document.]

With the Institute at the World’s Largest Rye Distillery

An important feature of the program foffered to the American Institute of Chemical Engineers during its Baltimore meeting, was a visit to the rye distillery of the Calvert Distilling Company, at Relay, Md. So that those readers who did not take part in the inspection, could still, in effect, “visit” this modern plant a Chem. & Met. editor preceded the engineers, recording below what they saw.

When prohibition was repealed three years ago, one company that was ready and waiting to do its part in curing the Great American Thirst was the Maryland Distillery, Inc., which forthwith set about building the nucleus of what is today the world’s largest distillery devoted exclusively to rye whiskey. Having acquired the Calvert Distilling Co., the merged company was itself merged in 1934 with the Distillers Corporation, Ltd., of Canada, so that today it is, like the Seagram organizations of the United States and Canada, an important link in the tremendous chain forged together as Distillers Corporation-Seagrams, Limited.

The plant is built on a site a few miles south of Baltimore with direct rail connection to the Baltimore & Ohio R.R. Physically, it is impressive, occupying a tract more than a quarter-mile in length, with 18 major and several minor buildings, covering an area of about 18 acres. Most notable in the general panorama are the five rack houses—bonded warehouses with a capacity of 256,000 bbl. in which all the whiskey made in the plant is stored for a period of four years, or more. These building aggregate over 15 acres of floor space. In them the charred white oak whiskey barrels are racked three or six high per floor, depending on the type of building.

Possibly the chemical engineering features of the plant are less impressive, but they are none the less interesting. Among them should be mentioned the close quality control exercised at every point in the process from grain purchase to blending and bottling and the liberal application of recorders and automatic regulators that is evident on the equipment.

Here the grain is granulated in three-pair-high roller mills

Perhaps the most effective way of viewing the plant will be to follow through the various stages of the process, step by step. Rye (which comes generally from Poland or Latvia) together with barley malt, bottles, cartons and fuel are received on one or the other of three railroad sidings running through the plant grounds. (It is an unfortunate fact that owing to poor quality, only small quantities of domestic grain rye can be used.) The grain and malt are unloaded at a 25,000 bu. storage elevator, adjacent to the fermentation and still buildings, by means of an electric screw conveyor capable of moving 1,000 bu. per hour. These materials are lifted mechanically to the topmost floor where they are first passed over scales, then cleaned thoroughly, and the screenings, averaging about 2 per cent, discarded and removed from the plant. From the storage hoppers, both rye and malt descend over magnetic separators into 130-bu. per hour roller mills of the three-pair-high type. Two mills are employed for grain, one for malt. Constant supervision in milling is necessary to secure the desired character of granulation—a maximum exposure of the starch grains without production of flour. Elevators lift the milled products to weigh hoppers at the top of the still building, ready for delivery, at the plant capacity rate of 4,085 bu. per day, to the mashing equipment.

At this point, it will be desirable to digress long enough to mention two auxiliary services that are extremely important in a distillery: water and steam. Five deep wells are pumped to supply the company’s 14 million gallon reservoir, and the flow of a spring-fed stream has recently been tapped to complete the requirements. Before it enters the plant, the water is passed through a coagulating flume where it can be treated with alum if required. It is then aerated for iron removal, passed through a settling basin and enclosed sand filters, handling 900-1,200 g.p.m., and finally chlorinated. All of the plant’s water with the exception of a small part of that required for cooling purposes is so treated. Boiler make-up, which constitutes some 70 per cent of the boiler feed, is treated in an 8,000 g.p.h. hot process limesoda softener. All water required for reducing the strength of the final still product to standard proof for bonding is produced in a 1,300 g.p.d. steam-heated copper water still.

The boiler house is equipped with three tubular boilers, one of 800 and two of 250 hp. rated capacity, totaling 130,000 Ib. per hour evaporation. The smaller boilers, Which generate at 250 Ib., are oil-fired while the larger, generating at 375 Ib., may be fired either with oil or pulverized coal. About a third of the plant’s electric power requirement is supplied through a turbo-generator exhausting to the low pressure steam mains at 17-20 Ib. The remainder of the process steam and heating load is provided by boiler steam passed through pressure reducing valves.

Returning to the plant operations proper, we find concentrated in the still house and adjoining fermenter house most of the actual manufacturing of the distillery. Under government supervision the milled rye and malt are weighed into batches containing about 15 per cent malt and 85 per cent rye and dropped into warm water contained in the mashing equipment. This equipment includes a 14,000 gal. mash tub and two 5,800 gal. mash converters, the former a vertical agitated tank supplied with a perforated steam coil, and the latter horizontal steel tanks with horizontal paddles and a number of live steam connections. A charge for the tub consists of 12,637 lb. of rye and 1,941 lb. of barley malt, and for the converters, 60 per cent of this quantity, with about 22 gal. of warm condenser water for each bushel of grain. In mashing, the mixture is quickly heated with steam to 150 deg. F. and held at this temperature for an hour. During this operation the diastase of the malt acts on the starch of the grain, liquefying it and converting it into the fermentable sugars, dextrine and maltose. At the completion of the holding period, the saccharified mixture is discharged to a drop tank and then pumped through a double-pipe cooler where it is lowered in temperature to 80 deg. F. before passing into one of the 15 large fermenters. The total mash tub cycle is about two hours. Three mash tub charges, or five converter charges, constitute the quantity required to fill a single fermenter.

The only raw material not so far considered is the yeast which, aided by a catalytic enzyme, zymase, given off by it, serves to convert the sugars of the mash into alcohol and carbon dioxide. Propagating the yeast is one of the most critical steps in distilling, calling for the use of a selected pure culture yeast which is grown carefully under the most suitable conditions. The culture is started in the laboratory, using a malt extract as a culture medium. After sufficient growth, it is transferred to the plant where, in the “dona room” its growth is continued in four small tinned copper vessels equipped with cooling water jackets. At the end of a suttable interval it is again transferred to four 3,000 gal. tinned copper-bearing-steel tanks. Finally, some 35 hours after it has left the laboratory, the yeast has grown to a point where it can be used for inoculating the fermenters. A single small converter, similar to the two larger ones used for mashing, is provided for preparing the yeast mash employed in these growing operations. Half barley malt and half rye malt is used for this purpose.

Fermentation of the mash takes place in 15 40,000-gal. open fermenters, constructed of copper-bearing steel and coated internally with a vegetable-base paint. Each fermenter is provided with a perforated air pipe, a cooling coil and a live steam connection for sterilizing. Five fermenters are started each day, the cooled mash being run in, diluted with water to about 35 gal. per bushel, and the yeast added. After 48 hours, when the alcohol content has reached about 9 per cent, the contents of each fermenter, now called “beer,” is dropped to one of two beer wells, ready to be pumped over the stills. Believing that the best product is obtained in open fermenters, the company does not attempt to recover carbon dioxide.

Two stills are provided, one a three-chamber charge whiskey still and the other a continuous beer still. The three-chamber type, although it is somewhat less efficient thermally than the other, is generally considered to give a better product, particularly where a heavier body rye whiskey is desired. It contains four chambers, one over the other, the top one serving only as a beer heater. Each of the lower chambers has its vapor space connected to vapor pipes discharging beneath the surface of the beer in the chamber above, while the bottom chamber is equipped with an external heater provided with 198 2-in. tubes and heated with both exhaust and live steam. Operation of this still is as follows: every 17 minutes a charge of 1,900 gal. of beer is admitted to the top compartment while, at the same time, the previous charges are each dropped one compartment. Thus, each charge is boiled three times, the third time—when it is nearly dealcoholized—with steam, and the first and second times by the ascending vapors. From the third compartment, vapors pass to the condenser, while from the bottom, the exhausted slop is drained to a storage tank, pending recovery of the spent grains. This still produces 140 wine gal. of high wines and 70 gal. of low wines per charge. The high wines, draining to suitable high wine tanks on the floor below, are later redistilled in a doubler, while the low wines, containing the bulk of the undesirable congenerics, are later returned to the still with the beer feed.

The continuous still is of the usual type, with bubble caps in the upper chambers, and perforated plates in the lower. At its capacity of 4,000 gal. of beer per hour, its hourly output is 375 wine gal. of high wines, ready for the doubler. This latter piece of equipment, of which the plant has two, is a simple pot still consisting of a copper body heated with a steam coil and connected by a tall vapor pipe with a condenser. The output of the doublers goes to the cistern house at a concentration of 112-115 proof where it is held in one of four 11,750-gal. copper tanks until it has been reduced with distilled water to 103 proof, the concentration at which it is bonded. The reduced whiskey is then run into internally charred white oak barrels which are transported to the several rack houses, there to be matured for the bonding period, or longer.

One indispensable phase of modern distillery practice is the efficient recovery of the spent grains for cattle feed. The dealcoholized slop from the stills is allowed to settle and the clear liquor decanted and pumped to a triple-effect evaporator where it is concentrated to a syrup containing about 25 per cent solids. The settled solids, on the other hand, are first partially dewatered on a rotating copper screen, followed by a traveling-screenbed press, then dried in a series of steam-heated rotary dryers. Of the four dryers used, the first two are fed in parallel with each other, but in series with the remaining two. Syrup from the evaporators is added to the partially dried grains in the screw conveyors connecting the discharge end of each dryer with the feed end of the next one. By this combination of drying and evaporation, then, the 92 per cent initial moisture of the slop is reduced to 5 per cent in the finished product, which is elevated to a packing floor and bagged for sale and shipment. Although this recovery has as its primary purpose removal of an otherwise troublesome waste material, it yields in the neighborhood of 11 Ib. of feed per bushel of grain mashed, and proves to be a profitable operation.

One of the 15 40,000-gal. fermenters at its stage of greatest activity

All that remains of our plant visit is to describe briefly the blending and bottling operations carried out in two of the larger buildings. Since none of the whiskey made at the plant has at the present attained sufficient age, all that is now passing through these final departments is obtained from affiliated companies. Various whiskies brought into the blending or “rectifying” department are combined either with each other or with neutral spirits, by methods which can only be described as an art, to produce blends developing to the maximum degree certain desirable characteristics. The blends, or if desired, certain straight whiskies, are then pumped to elevated filling tanks and piped down through pulp filters to the bottling machines. Here, in a highly mechanized department, on eight conveyorized bottling lines, the various grades acquire bottles, caps, labels, revenue stamps, and cartons—meanwhile being constantly inspected every step of the procedure. As a final safeguard, each case is weighed and stamped with its weight for protection against possible shortage, then dropped through a chute to the shipping department on its way to the American public.

In conclusion, we wish to acknowledge the kind assistance of various individuals, including Dr. H. E. Bacon, Jr., an associate of Sheppard T. Powell, consulting engineer of the distillery; and among the distillery personnel, of E. M. Fleischmann, president, J. O. Herrmann, vice-president, D. Garlock, superintendent and plant engineer, and E. F. Zepp, chief engineer. To all of these gentlemen thanks are due both for their aid in securing the necessary information for this article and in checking its final accuracy.

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