Conclusions Preliminary laboratory tests and later wind­ The thermal design study for a Pyroceram ra­ tunnel tests showed that the large compressive stress dome for a Mach 4 missile was successfully con­ at the point of the radome would not cause any ducted. Investigation of the effect on thermal stress structural problem. Finally, correlation of strain­ of blunting the radome disclosed that little or no gauge measurements made during wind tunnel tests reduction in maximum tensile thermal stress may be demonstrated that both the theoretical method expected with a 1.35-in.-radius nose. Thus, one used to predict temperature gradients and the cannot automatically assume that the increased cylindrical theory used to determine thermal drag caused by blunting is justified by the reduc­ stresses give acceptable results for use in radome tion in thermal stress. thermal design. a scientist and his hobby the TECHNOLOGY of -MAKING

G. H. Mowbray

Wine has been called many things was "the mirror of the heart"; to Others have expressed their feelings since the first known reference to it Shakespeare, "a good familiar crea­ less kindly, if no less poetically. Mil­ in Middle Eastern writings dating ture"; and to William Gilbert, "a ton spoke of "the sweet poison of from 2100 B. C. To Aeschylus it panacea for ev'ry conceivable ill." misused wine"; Pope, of "inflaming wine, pernicious to mankind"; while in Proverbs we are warned that "it biteth like an adder and stingeth like a serpent." No matter which of these positions one espouses-and all of them have merit on occasion -officially, wine is the fermented juice of the grape used as a bever­ age, or so says the Oxford Diction­ ary.! Federal description, however, is a little more verbose, defining grape wine as "wine produced by the normal alcoholic fermentation of the juice of sound, ripe grapes (in-

G. H. Mowbray, an experimental psycholo­ gist, is a member of the staff of the Theoretical Problems Group of the Re­ search Center. Dr. Mowbray is the author of " Some Human Perceptual Limits" in the Digest of Jan.-Feb. 1962.

1 Oxford Universal Dictionary on Historical The author in his keeps a close watch on the growth and health of highly Principles, 3rd ed. (rev. ), Clarendon Press, prized imported vines. London, 1955.

18 APL Technical Digest eluding restored or unrestored pure condensed grape must), with or without the addition, after fermen­ tation, of pure condensed grape must, and with or without added fortifying grape spirits or alcohol, but without other addition or subtrac­ tion except as may occur in cellar treatment ; Provided, that the prod­ uct may be ameliorated before, dur­ ing or after fermentation, by either of the following methods . ..."2 For practical purposes there are .. only three basic types of wine. They can be denoted briefly as , , and . Fortified are natural wines to which has been added the dis­ tilled spirit of the grape, i.e. brandy. Sampling to determine its sugar content, G. H. Mowbray is seen here in the cool cellar area where fermentation takes place. They may be either sweet or dry ; thus, they may have a sweetness beverages that need not concern us has an alcoholic content that does (artificially derived ) that may be here. The production of true cham­ not exceed about 13 %, and it may detectable to the palate, or they may pagne is a tedious and time-consum­ be red, white, or rose. It is not very be lacking in sweetness-some say ing process that results in a unique intoxicating except in larger quanti­ "tart," although this is by no means drink that is almost universally ties than most people are willing to an exact description. The fonner appreciated. Its effervescence is pro­ consume. When drunk with a meal are the ports, , muscatels, duced by a carefully controlled sec­ it adds a touch of festivity as noth­ and madeiras. Basically, they are ondary bottle fermentation that de­ ing else can do. In fact, an ordinary naturally fermented wines that have mands constant care and handling. meal consumed with wine becomes been fortified with brandy, with or The resulting product is a wine of something extraordinary. The old without the addition of sugar prod­ about 14% alcohol that has no saying that a meal without wine is ucts. They are known generally as equal in terms of finesse, finish, and like a day without sun has much to dessert or aperitif wines. The sweet palatability. The desirability of these recommend it. Today, there is no ones (port, madeira, muscatel, etc.) wines is recognized by connoisseurs excuse for the fonner although the are usually served after dinner with as well as by Internal Revenue Bu­ latter cannot be guaranteed under fruit or biscuits and cheeses, while reau agents who tax them exorbi­ any circumstances, even in Cali­ the drier ones, most often , tantly. fornia. are served as appetizers before din­ Natural wines are the wines that Since the basic process involved ner. The dessert wines usually have are prod uced by the complete fer­ in the production of any wine begins an alcoholic content of 18 % to mentation of expressed grape juice. with a natural wine, that is what 25 % and are nearly always sweet­ That is to say, all of the sugars in will be described here. It is basically to-very-sweet. The sherries have a the juice of the grape are converted a simple one as practiced by our similar alcohol potential but gener­ to alcohol and carbon dioxide so ancestors, but in the name of stand­ ally are described as "dry." This is that the resulting wine can be de­ ardization it has become something not to deny the existence of sweet scribed as "dry." These are the table less than simple. sherries, for there are some, but wines of the world, with an alco­ A Little Chemistry they are in the minority. holic content varying between 9% In 1810, Gay-Lussac, the French Sparkling wines are epitomized by and 13 % for the most part. Oc­ chemist, first described the reaction the , although there are casionally, but only very occasionally, that occurs when freshly pressed a great many inferior wines that are their alcoholic content runs higher grape juice is converted to wine. His made acceptable to some by the ad­ (to 15 % ), but these are exceptions. analysis revealed the following: dition (naturally or artificially) of Exceptionally also, they contain re­ carbon dioxide. The latter are sold sidual sugar that has not been con­ C SH1 20S = 2 C 2H 50H + 2C02. under various names, usually pre­ verted to alcohol by fermentation, as (grape sugar = ceded by the adjective "sparkling." in the case of sauternes of Bordeau, alcohol + carbon dioxide) There are many federal restrictions barsac of the same region, and the This is the overall expression that on the production of sparkling-wine outstanding wines of the Rhine and says that a quantity of grape sugar the Moselle in Germany, of which, in the presence of the proper yeast 2 U.S. Federal Alcohol Administration, alas, there are all too few. is converted to a certain amount of Regulations No.4 Relating to Labeling and Advertising 0/ Wine, U .S. Government The bulk of the wine consumed alcohol plus some carbon dioxide. Printing Office, Washington, D .C ., 1948. the world over is natural wine. It While Gay-Lussac's formula is gen-

1u1),-August 196-1 19 erally correct, a great deal of an­ romycetes (the fermentation yeasts ) or "must," as it is technically known, alysis directed toward a more exact give the signal, a wild game of follows. determination of the process has oc­ musical chairs ensues, creating chaos SUGARS-The primary sugars are cupied wine chemists for the last out of what had been a somewhat dextrose and levulose, which are one hundred or more years. orderly arrangement. When order is usually present in a 1: 1 ratio at ma­ Careful observation of the above again restored, there is wine, and turity. Since levulose is nearly twice relations indicates that the fermen­ some products have been created as sweet as dextrose, the significance tation process is thus nothing more that were not in the original solu­ of this ratio is apparent. Fluctua­ than a molecular readjustment of tion. tions in the ratio caused by grape the carbon, hydrogen, and oxygen of Temperature is very important to variety, climate, or whatever, must grape sugar. However, there is much the total process because of the in­ be taken into account by the wine more to it than that. In the first fluence it exercises upon the rate of maker who desires a standard prod­ place there are two basic types of molecular exchanges and upon the uct. Practically no sucrose (cane grape sugar, namely levulose and solubility of various acids. sugar) is found in grapes of the best wine varieties, but other types dextrose, having the following forms: Theoretically, according to Gay­ may contain as much as 10 % . Traces Lussac's formula, yields of 51.1 % CH 0H of other sugars and related com­ 2 alcohol and 48.9 % carbon dioxide pounds such as the pentoses and I should be possible from a quantity CO pectins are usually present. of grape sugar. In actual fact the I alcoholic yield will depend on many CHOH ACIDs-The biological stability of things, among which are the amount LEVULOSE wine is largely the result of its be­ I of by-products, amount of sugar CHOH ing buffered to a relatively low pH. used by yeasts as metabolites, sugars Grape must contains two major I used by other microorganisms, alco­ CHOH acids, one of them relatively strong, I hol lost by evaporation, etc. While the other less so. They are d-tartaric in the strictest academic sense all and l-malic, respectively. Other CH2 0H of the foregoing is indisputable, still acids present in very small amounts the difference between theory and include citric (0.01-0.03 %), oxalic CHO practice is not monumental. Alco­ (less than O.Ol o/c) , and traces of I hol yields of from 90% to 95 % phosphoric. The total acidity of CHOH theoretical are regularly obtained. musts is calculated as tartaric acid I So, freshly pressed grape juice con­ and may range from 0.3-1.5 % . CHOH taining 24 % sugar will, with proper Musts from the best wine grapes DEXTROSE I handling, result in a wine whose register 0.6- 1.2 %, but climate is an CHOH alcoholic content is about 13 %. important determining factor. The I Grape juice before fermentation same grape variety grown in the CHOH contains many things other than warm, dry climate of California and I sugars, and the proper balance of on the cool, more humid slopes of CH 0H 2 these is of great importance in de­ the Cote d'Or will yield vastly dif­ termining the character of the fin­ ferent total acidities, those from the Thus, as one eminent writer on the ished wine. A general statement cooler regions being higher in acid­ subject has suggested, when saccha- about the composition of grape juice, ity and thus lower in pH.

The making of wine is a task for many hands, as this series of typical activities dearly shows. The vines must be carefully and frequently cultivated, and willing people must spend long hours picking the fruit and hauling it to the processing

20 APL Technical Digest NITROGENOU S CON STITUENTS­ From These Grapes A few centuries after the settle­ These vary widely with soil condi­ Thus, as can be seen, the grape ment of North America the Euro­ tions, especially with respect to am­ is the most important element in peans felt the real brunt of Colum­ monia nitrogen. The nitrogen frac­ successful wine-making. This has bus' inqUIsltIveness. A tiny root tions reported in musts include am­ been known for centuries, but the louse, called phylloxera, native to monia, amino acids, amide, humin, history 'of the acquisition of this these soils but unknown to the rest phospho-tungstic acid, and protein, knowledge is a fascinating study in of the world, was introduced to the among others. Of the amino acids, itself. Our forefathers in North virgin soils of France. The result glutamic acid and arginine are pres­ America found grapes growing in was the total devastation of the ent in significant amounts, while the abundance in the wild state and magnificent that had been others, about twelve in number, are concluded that this was paradise in­ the pride of the nobility since the less evident; there is great diversity deed. They soon had cause to revise days of the Capets. The extent of of opinion, however, not only as to their opinion because the native the catastrophe is difficult for us to amounts but also as to which are grapes produced a bitter, sour wine imagine-we who have never known actually present in detectable quan­ with objectionable and unfamiliar the great pre-phylloxera wines. tities. flavors. Today we call them "foxy" Within a few years all of the vine­ wines. They spent literally millions yards of France had been replanted VITAMINS- Although vitamins in in their efforts to import the Euro­ on grafted American rootstock that musts are important primarily as pean grape ( vinifera ) and was resistant to the root louse. In accessory growth factors for micro­ make it grow in this unfavorable addition, a vigorous program of hy­ organisms, some are in sufficient climate. Without going into any brid development was begun that quantity to be useful in human nu­ great detail, the upshot of it all was produced literally thousands of va­ trition. Small amounts of vitamin A that every attempt failed. Therefore, rieties of grapes that were resistant and ascorbic acid have been re­ grape culture was virtually aban­ not only to phylloxera but to ex­ ported, the latter only in fresh doned except by the Spaniards who treme climatic conditions and un­ grapes, however. Thiamin and ribo­ invaded California and who, for the favorable soil characteristics as well. flavin are both present in apprecia­ purpose of the Sacrament, persisted It is the latter development that ) , ble quantities, as are pyridoxin (B6 in producing an alcoholic beverage is of interest to us. These hybrids, pantothenic acid, and nicotinic acid. from the Mission grape to serve genetic mixtures of the old-world Recent analyses suggest that there their religious purposes. California strains and disease-resistant Ameri­ is also a vitamin P factor present wine growers to this day suffer from can stock, have produced varieties that may be responsible for the the zeal of those early devotees. For that not only thrive in unfavorable tonic-like qualities attributed to in truth, the Mission grape leaves conditions, but also produce grapes wine. much to be desired as a source for from which European-type wines wine production, and we can only can be made. Thus we are now in a MISCELLANEous-In addition to the conclude that those pioneering de­ position to accomplish what our constituents noted above, grape vouts cared little for what they forebears sought in vain to do. musts also contain tannins, pigment drank so long as it was red and My personal interest in wine stems compounds, many enzymes, and contained alcohol (as a preservative, from a lengthy stay in Europe where odorous substances about which rela­ of course ) . The poor reputation of I completed my graduate studies, tively little is known, but which play pre-prohibition California wines can but my active participation in grape a considerable role in the quality of be traced largely to the early intro­ culture and wine making is the the finished product. duction of this grape into the area. direct outcome of the pioneering

area. There the srapes are crushed and stemmed betore beins feel into a hydraulic press to extract the juices. These, finally, are poured into casks for the Ions fermentation and aseins processes that tum the srape juice to .

July - A ugust 196-1 21 efforts of others. The French hybrids addition of stupefying potassium bi­ anathema; this second fermentation were introduced into Maryland sulfite to the must, to predominate only serves to further flatten the about three decades ago and, fol­ in producing the flavor characteris­ taste. lowing much painstaking experi­ tics common to the type of wine The malo-lactic fermentation is mentation, several vaneties have being produced. These cultured not completely understood, but some proven compatible with local climate yeasts have been developed through experts believe that short-rod or and soils ; so much so that a small the years to have a high sulfur tol­ coccus-type bacteria are involved. It but growing wine ind ustry has been erance, hence they are little, if at is without doubt an anaerobic re­ developed with them. I learned of all, affected by the addition to the action that is temperature-dependent, this less than ten years ago and al­ must of the sulfurous antiseptic. the optimum temperature being be­ most immediately began planting Within a few days-the actual tween 60° and 70 °F. The two prob­ my own vineyard. The results have time depending upon the ambient able reactions are as shown in the been so favorable that my enthusi­ temperature-the sugars in the grape box below. asm for the venture has increased juice are converted to alcohol and Within a few months in a cellar over the years in direct proportion carbonic acid gas, as previously men­ of the proper temperature, the wine to the quality of the wine we can tioned. Since this process requires has completed its secondary fermen­ produce. Being an experimenter by oxygen for its fulfillment, the fer­ tation and the solids have been pre­ inclination, which is to say compul­ mentation containers have been only cipitated, leaving a liquid that is sive, I am always seeking ways to partially filled. When fermentation clear and limpid. improve what is even now a very is complete, as determiried by meas­ At this point the wine maker good thing indeed. Consequently, urements for residual sugars, the carefully removes the liquid from its new varieties of grapes are con­ containers are filled' to capacity and sediment by siphoning or pumping. stantly being tested. That is all part tightly sealed--or sealed with a This assures that unwanted flavors of the fun, for who knows but some­ water valve to allow gases to escape and tastes will not be derived from day Maryland may rival California but prevent any oxygen from enter­ the deposits of dead yeast cells, tar­ in the quality if not the quantity of ing. This completes the primary trates, and other precipitates that its wine. Some say we already have. fermentation. Technically the re­ have accumulated in the bottom of The Process sultant liquid is wine, but a sip his casks. Each of these siphonings The actual process of making would tell you that it is far from is accompanied by a measured dose wine has not changed basically since ready to drink. of sulfur to ensure that unwanted its first discovery, probably by acci­ At this point, the wine has a bacteria are destroyed and that oxy­ dent, many millenia ago. The freshly yeasty flavor, is thin and exceedingly gen reduction does not occur. Cer­ harvested grapes are brought to the acid. Throughout the next few tain anaerobic bacteria, particularly where they are crushed and months it is left to age-this con­ the long-rod variety, can completely pressed and allowed to ferment for sisting primarily of settlement of the spoil wine within a few days, while a period of time. Formerly, the fer­ solids in the wine and a secondary exposure to oxygen in unwanted mentation was left to the natural, fermentation that consists of a par­ quantities can render a wine flat wild yeasts that every grape collects, tial conversion of the malic acid to and insipid, giving it a madeira-like willy-nilly, in its progression from a the softer and more palatable lactic flavor, highly esteemed for certain hard, green, pea-like growth to the acid. This is the well-known malo­ types of wines but objectionable in rich golden or purple lusciousness of lactic fermentation that wine makers dry table wines. full maturity. Today, in most win­ of France and the Eastern United From this point on ageing is the eries, the fermentation is not left to States so desire but that the Cali­ only reason for not selling the prod­ the vagaries of whatever yeasts may fornians avoid like the plague. Be­ uct so laboriously derived. The slow have chanced to settle and multiply cause of the initially lower acidity exchange of oxygen through the on the grapes. Instead, yeast cul­ and higher pH of the Californians' casks (usually oak or redwood ) com­ tures of predictable characteristics grapes, any further reduction of pletes a process that was begun with are introduced early, and they soon acidity such as occurs in the malo­ the proper maturation of the grape marshall their forces, aided by the lactic fermentation is to them pure on the vine. For red wines of prime

CH COOH DPN malic CH COOH 3 2 CH3 D PNHz lactic CHa I dehydrase I f3 decarboxylase I dehydrase I CHOHCOOH ) COCOOH ) COCOOH ) CHOHCOOH (malic acid ) -H (oxalacetic acid ) - CO 2 2 (pyruvic acid ) + H 2 (lactic acid )

CH COOH DPN, Mn++ malic 3 CHa D PNH 2 lactic CHa and I dehydrase I dehydrase I CHOHCOOH ) COCOOH ) CHOHCOOH -CO -H 2 z + H 2

22 APL Technical Digest WINE-MAKING (continued) HONOR S AND APPOINTMENTS quality, such an exchange lasting for 3 to 7 years may be beneficial, while R. E. Gibson, Director of the of the APL Security Office, has been for white wines one or two years at Applied Physics Laboratory, has elected chairman of the Baltimore most are all that are needed. accepted appointment as a member Chapter, American Society for In­ At the end of the ageing period, of the Technical Committee on dustrial Security. determined by the type of wine and Space and Atmospheric Physics of A. G. Schulz, a supervisor of the by the characteristics of the the American Institute of Aeronau­ Excitations Mechanisms Group in the or the year of its production, the tics and Astronautics. Research Center, has been appointed wine maker filters the wine by what­ R. A. Dickmann, supervisor of a member of the National Academy ever process he may have decided Personnel Research and Analysis, of Sciences-National Research upon, bottles it, and sells it for the the Personnel and Education Group, Council Committee on Basic Re­ future enjoyment of those whose has been appointed chairman of the search Advisory to the U. S. Army privilege it is to comment and criti­ Computer Personnel Research Group, Research Office (Durham) for a cize. Whatever their reaction, you a national organization concerned period of three years, with concen­ may rest assured that year after year with selection, training, and appraisal tration in the field of optics and re­ he will tend his vines and produce of computer personnel. lated research. Retiring from this his wines. You may have decided D. W. Fox, supervisor of the committee are S. N. Foner, super­ against them, but that will not dis­ Aeroelasticity and Vibration Analy­ visor of the Electronic Physics courage him, because he drank his sis Project, is one of three recipients Group and chairman of the Edi­ wines before you did and found of a joint grant awarded by the Sci­ torial Board of the Digest, repre­ them satisfying. entific Council of NATO in support senting the sub-field of atomic and Chacun a son goQt. of "Research and Collaboration in molecular physics, and C. K. fen, the Estimation of Spectra Oper­ supervisor of the Microwave Physics .111. ators." Group, representing the sub-field of PUBLICATIONS D. E. Rutz, a member of the staff microwa ves. W. H. Avery and G. L. Dugger, "Hypersonic Airbreathing Propul­ --...... ADDRESSES ....-~-- sion," Astronautics and Aeronau­ tics, 2, June 1964,42-47. F. J. Adrian; "Comment on the MathematischesForschungsinstitut, R. H. Cantrell, R. W. Hart, and Valence-Bond Theory of f3 Atom Oberwolfach-Walke, Schwarzwald, F. T. McClure, "Linear Acoustic Hyperfine Splitting," American Germany, June 16, 1964. Gains and Losses in Solid Propel­ Physical Society, Washington, I. B. Irving and W. J. Billerbeck, lant Rocket Motors," A.I.A.A. ]., D. C., April 27-30, 1964. "Thermal Problems Involved in 2, June 1964, 1100-1105. R. M. Hanes, "A Story of a Book," Space Simulation," First Interna­ S. N. Foner, R. L. Hudson, and 33rd Inter-Society Color Council, tional Congress on Vacuum Tech­ B. H. NaIl, "Admittance Measure­ Symposium on Color Education, niques in Space Research, Paris, ments of Solid Propellants by an New York, May 4-5, 1964. France, June 29, 1964. Acoustic Oscillator Technique," J. F. Bird, "Theory of Massive Gravi­ D . W. Fox, "Lower Bounds for A.I.A.A. ]., 2, June 1964, 1123- tational Condensations," Harvard Eigenvalues of Sums of Resolv­ 1129. University Observatory, Collo­ able Operators," l'I nstitut des J. F. Bird, "Massive Condensations quium, May 29, 1964. Mathematiques Appliques, l'Ecole in Interstellar Matter and Stellar R. P. Suess and L. B. Weckesser, Poly technique de I'Universite de Associations," Rev. Mod. Phys., "Radome Thermal Design for a Lausanne, Switzerland, July 6, 36, July 1964, 717-747. Mach 4 Missile," Ohio State Uni­ 1964. R. W . Hart, R. H . Cantrell, J. F. versity, Electromagnetic Window C. K. Jen, Invited Lecture Series on Bird, and F. T. McClure, "Non­ Symposium, June 2, 1964. Microwave Spectroscopy, Aca­ linear Effects in Instability of A. A. Westenberg, "Application of demia Sinica, Taiwan (Formosa), Solid Propellant Rocket Motors," Quantitative ESR to Gas Phase Science Symposium, July-Aug. A .I .A.A. f ., 2, July 1964, 1270- Chemical Kinetics," University of 1964 (8 weeks). 1273. Minnesota, Department of Me­ R . R. Newton, "Orbital Elements chanical Engineering Colloquium, The papers listed below were pre­ from Doppler Tracking of Three June 2, 1964. sented at the Tenth Symposium Satellites," ]. Spacecraft and J. T. Massey, "Lasers-Their Opera­ (International) on Combustion, Uni­ Rockets, 1, July-Aug. 1964, 441- tion and Application," Research versity of Cambridge, Cambridge, 444. Analysis Corporation, McLean, England, Aug. 16-21, 1964: R. E. Walker and M. Shandor, "In­ Va., June 10, 1964. W. G. Berl, P. Breisacher, D. Dem­ fluence of Injectant Properties for D. W. Fox, "Lower Bounds to Eigen­ brow, F. Falk, J. T. O'Donovan, Fluid-Injection Thrust Vector values," Conference on ((Funk­ J. L. Rice, and V. Sigillito, "Com­ Control," ]. Spacecraft and Rock­ tionalanalytische Methoden In bustion Characteristics of Mono­ ets, 1, July-Aug. 1964, 409-413. der Numerischen Mathematik, propylpentaborane Flames";

.July -August 196-/ 23