A Laboratory Water-Bath for Cooking, Mashing, and Fermentation Studies HAROLD W. COLES AND WILLIAM E. TO1
T
HE water baths described in the recent literature ( I , $ , S)
and those commercially available were too small for the authors' requirements in fermentation studies. A bath was desired in which the three stages of cooking, mashing, and fermentation could be conducted with volumes varying from only a few cubic centimeters up to 10 liters. The bath shown in Figures 1and 2 was designed to satisfy these requirements. The bath is large enough (300 liters) to accommodate two 12liter flasks if desired. The over41 dimensions are: 116.2 em., 46.5 inches (long) X 70 cm., 28 inches (wide) X 66.88 om., 26.75 inches (high), not including the angle-iron stand. The inside width is 50 cm. (20 inches) and the length is 100 cm. (40 inches) at the widest points. The bath is insulated with at least 5 om. (2 inches), at the narrowest points, of building insulation wall bats, 37.5 X 57 em. (15 X 23 inches). The walls are of 0.62-om. (0.25-inch) Transite with 17 standard aluminum angle 0.3 X 2.5 em. (0.125 X 1 X 1 inch). The bottom is of white pine. The inside of the oval bath is tinned cop r The bottom i S false and has in the middle, crosswise, a rig; partly visible in Figure 1, A, directly under the stirrer. This ridge, 15 em. (6 inches) higher than the lowest part of the bath, effectively eliminates dead water swts. The denth of the bath at the t k g h is 60 cm. (24 inches). The larger glass apparatus is held by two types of baffles which are introduced into slots, B, soldered on the sides of the bath, 25 om. (10 inches) from each end. One type, C, holds the tall cvlindrical Pyrex jar (45 em., 18 inches high and 15 cm., 6
'lhe bath IS emptied ny means 01 two a:13-cm. (1.3-mcn) draiilr (type K tioiicoppr-tubmg) ,urd thrre i.i also an OVQT~IOW 0penir.g of the ?:mie size j u s t undrmeatl tLc cniqiccc, H , wliich is m;tdr d a 0.9-rm. (0..375.inch1 strrl ~ I a t e .lli.25 cm. 16.5 inches) in width. restina on al&um &de. The watei is stirred by a 20-crh. (%inch) 3-blade L. H. aiuminum propeller, I, mounted on a brass shaft. The jar contents, D,are stirred by a Monel screw-type stirrer. The brass center pulley, J, 5 om. (2 inched in diameter. has a meed of 254 r. D. m. The oastiron end &Ileys, K, ha& diametersof 9.4 em. (3.75inches) and am
hearings and th&t ball beahgs.' Figure 1 shows further the steam ring, M,directly above the stirrer, the water pipe, N, used for filling the bath, and the thermoreeulator. 0. which has a 15-cm. (6-inch) extension (Aminca)': The thermometer, P, is a special length 101' C. instrument. T
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$dished & m & m sheet, 0.3 em. (01125 inch) thick, reinforced at several places with additional aluminum strips. The baffle, C is 23.5 cm. (9 inches) high and 49.67 om. (19.87 inches) long. The slots attached to the wdl are soldered at the lower end: The top of the bath is covered with copper sheet and refngerator rubber door gaskets are tacked about each opening upon which rest the aluminum covers, F, when the bath is in use. These covers are held in place by the screw fasteners, G, serve as another sumort for the 12-liter flasks. and cover the bath shout the tall &linders when the water is at the boiling point.
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FIGURE 2.
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BATHFOR FERMENTATION WORE, SHOWING FLASK AND DETAILSOF ELECTRICAL AND HEATING DEVICES
WATER
hRMENTATlON
Figure 2 illustrates the mechanical, beating, &nd cooling f e e tures of the bath. The swed reducer, Q,is a Smith No. 2 BV reducer, 7.5 to 1 ratio, with the output &aft extending from the bottom. It is connected with the 0.25-horsepower motor, R, through a Boston 3-jaw couplin , 125 em 0 5 inch bole, FCN12. The steam is controlled %y 'a ioleniid S. mhmh. throuah a separate ~ i system, ~ e is also used for cold water control. B o t h steam &dwater lines have check valves, T,and strainer, U. The pipe, V,is used for introducing steam under full pressure when it is desired to heat the bath very quickly. The sheet steel box (20 X 20 X 10 em., 8 X 8 X 4 inches), W.
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The water line has a conneotion wlkrebv rhe water can hepassed thn.iiglr 1 woling cull f u r us? m hot svrjthpr. To inrawre 1l.e trmpcrrruw of flip rnsih. n !hcmlomrter may e tlie cylinder (Flrurr I), or a hde he susprnded from the e d ~ 01 for H thrrmomctcr mav Le bored throueh the rubber s t o.. m e r of .~ the 12-liter fl&k sho& in Figure 2. ~
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Literature Cited Clark, W. M., IND.ENG.CHEM.. ANN.. ED..11.41 (1939),
(1) (2) Deiss, C h m . Fabrik, 1935. 127. (3) Kattwinkel, R.. 2. anal. C h m . , 71. 46 (1927).
FIGURE1. WATERBATHPOR FERMENTATION WORK Saowmo COOXING AND MMHINQ ARRANQEMENT
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