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II. A treatise on thecultivation of the vine,and the method ofmaking winesVersion of record first published: 18 May2009

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[ 9 ]

II . A Treatife on the Cultivation qf the Vine, and the Method of making [/I/~nes.

[Continued from Vol. IX. p. 34z.]

I17. General Precepts refpec'ting the Art of managin~ Fermental ion.

W H E N the grapes have acquired the proper degree of maturity, if the atmofphere be not too cold, and if the vintage be of the proper volume, fermentation has no need of aid or a-ffif~anee. But thefe conditions, without which it is impof- fible to have a good refuh, are not always united, and it be- longs to art, in order to obtain a good fermentation, to com- bine all there favourable eircumttanees, and to remove every thing prejudicial.

The faults of fermentation arife naturally from the quality of the grapes, which is the fubjecCt of it ; and from the tem- perature of the air, which may be confidered as a very pow- erful auxiliary.

Grapes may not contain a fuffieieney of.fugar to produce a fufficient formation of alcohol : and this vice may be owing to the grapes not having attained to maturity, or to the fugar being diluted in too confiderable a quantity of water; or be- eaufe fugar, by the nature of the climate, cannot fuffi- eiently develop itfelf. I n all cafes there are two ways of eorrecCting the vice which exiles in the nature of the grapes ; the fiff~ confifis in conveying into the mufc that principle which it wants: a proper addition of fugar prefents to fer- mentation the materials necet"fary for the formation of al- cohol, and the deficiency of nature is fupptied by art. The antients, it appears, were acquainted with this procefs, finee they mixed honey with the mut~ which they caufed to fer- 17oent. At prefent, dire& experiments have beer_ made on this fubje~ ; but I fhalI confine myfelf to tranfcribe here the refuhs of thole made by Macquer.

"In'the month of OCCtober 1776 I procured from a garden at Paris a quantity of the white grapes called pineau and m~lier fufficient to make from twenty-five to thirty quarts of wine. They were wafte grapes, and taken, purpofely, in a bad flate of maturity, that there might be no hopes of making potable wine fi'om them : in nearly about a half of them, tingle grapes and even whole elufters were fo green that thei(aeiditv was iufupportable. Without taking asxy other precaution'than to feparate what were putrid, I caufetl the reft to be bruifed with the Ralks, and the ,juice to be

expreffed

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Io On the Cultloation of the Vine,

expreffed with the hand : the muK which iffued from them was exceedingly turbid, of a dirty-~reen eolour and of a fweetifh four taf~e, in whi~eh the acid-predominated fo much that it eaufed thole who tared it to make wry faces. I dif- folved in this muff a fuffieient quantity of brown fugar to give it the tafce of pretty good fweet wine; and, without. boiler, funnel, or fiarnace, I put it into a ealk in an apart- ment at the bottom of the garden, where it was left to itfetf. Fermentation took place in it on the third day, and main- tained itfelf for eight days in a very fenfible manner, but ttitl very moderate. After that time it eeafed.fpontaneouflv.

" The wine thence refuhing being newly made, arid ffitl turbid, had a pretty flrong and pungent vlnous odour; its taf~e was fomewhat harlh ; while tha~t of the fi,gar had dif- appeared as completely as if it had never exit~ed. I fuffered it to remain in the ea/k during the winter ; and having ex- amined it in the month of March, I found that, wit-hout having been drawn off or t~rained, it had become clear ; its tafLe, though f~ill pretty flrong and pungent, was, however, mueh more agreeable than it had been immediately after the fenfib}e fermentation; it had fomething fweeter and more racy, but was mixed with nothing that approached to fugar. I then put the wine in bottles, and having examined it in the month of O&ober I777, I found it to be clear, fine, ex- ceedingly brilliant, agreeable to the tafle~ generous, and warm;- in a word, like good whi te wine made from pure grapes which has nothinglufeious, the produee of a good vineyard in a good yeax. Severa| connoiffeurs, Whom I made to taf~e ,t, gave it the fame ehara&er~ and could not believe that it hadbeen made from green grapes, the ta~e of which had been eorre&ed with fugar.

" This fileeefs, which exceeded my hopes, induced me to make a new experiment of the fame kind, and fiill more decifive, on account of the extreme greennefs and "the bad quality of the grapes which I employed.

~' On the 6th of November 1777 I caufed to be eolle&ed, from the top of an atbour in a garden at Paris, a kind of large'grapes which never ripen properly in this climate, and whi-eh-we know only under the Iname of verj'~s, becaufe they are ufed for no other purpofe than to exprefs the juice before it becomes fpoiled, that it may be employed as a kind of four feafoning in cookery. Thole here alluded to had feareely begun t~ rot though the feafon was far advanced, and they haB been abandoned on the arbour as leaving no hope of their acquiring fuffieient maturity to be fit for the table. They were Iiil| fo h,rd that I refolved to make them burit over the

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and the ]~lelbod of rnakln g t/I27nes, r*

i~te in order to extra& the juice : the quantity they furniflaed was about eight or nine quarts. This juice had a very acid tafie, in which there could fcarcety be diltingui0aed a very flight faecharine favour. I diffotved fome of the commoneit eaffonade until it appeared to me to be very faeebarine. I required a great deal more than for the wine of the preceding experiment, beeaufe the acidity of the latter muft was much Rronger. After the fugar "was diffolved, the tafte of the liquor, though very faecharine, had nothing agreeable, be- eaufe the fweet and the four were perceived pretty Rrozigly and feparately in a difagreeable manner.

" I put this kind of muff into a jar fo as not to be entirely full, and covered it only with a cloth : as the feafon was al- ready very cold, I placed it in an apartment where the heat was always maintained at 13 or 73 degrees (59 to 6~ F.) by means of a ftove.

" ~bur days after the fermentation was not yet very fenfi- ble, the liquor appeared to me to be as faecharine and as acid ; but thefe two taites beginning to be better combined, the refult was a whole more agreeable to the talte.

~' On the 14th of November the fermentation was in full force : a lighted taper introduced into the empty part of the jar, was fpeedily extinguillled. "

" On the 3oth the fenfible fermentation had entirely eeafed, and the taper was no longer extinguithed in the in- terior of the jar. The wine which reftilted from it was, how- ever, ver.y turbid and whitifh ; its tafte had fcarcely any thing faceharine ; it was ttrong, pungent, and pretty agreeable, like that of generous warm wine, but a little gafeous and green.

• '" I elofed, the. j.'ar and put it .int° a.cool place, that the wine might bring ltfetf to perle&Ion by mfenfible fermenta- tion during the whole winter.

" Having examined this wine on the 17th of March I778 , I found that it was almoft entirely dear, the remains of its faceharine as well as its acid tafte had difappeared. The latter was that of pretty ttrong wine made from pure grapes : it was not unpleafant, but had no perfume or bouquet, beeaufe the grapes, which we call verjus, contain no odorous principle or aroma : there excepted, this wine, which was quite new, and which flill had to ~aln by that fermentation which I eall infenfible, prom;fed to oeeome racy and agreeable.'"

There experiments feem to me to prove, beyond all doubt; that the beft method of remedying the want of maturity in grapes is to follow the proeefs indicated by. nature ; that is to fay, to introduce into the mut~ that quantity of faeeharine principle neeeffary which it could not give them. This me-

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I z On the Cult~ahon of the Vine,

thod is the more pra&ieabte, as not only fugar, but alfo honey, molatt~s, and every other faecharine matter of an inferior price can produce the fame effe&, provided they have no difagreeable aceeffary taffe which cannot be deffroyed by good fermentation.

Bullion eaufed the juice of grapes, taken from his park at Bellegames, to ferment by adding from 15 to so pounds of fugar per muid*. The wine they produced was of a good quality.

Rogier, long ago, propofed to facilitate the fermentation of muff, and ameliorate wines by the addition of honey,-in the proportion of a pound to two hundred of muff. All there proceffes depend on the fame principle, viz. that no alcohol is produced where there is no fugar ; and that the formation of alcohol, and confequently the generous nature of wine, is con ftantly proportioned to the quantity of fugar exilting in the muff : it is-thence evident that wine ma}; be carried to any degree of fpirituofay required, whate~;er may be the pri- mitive quality of the muff, by adding to it more or lefs fugar.

Rozier has proved, and the fame refult may be obtained by calculating the experiments of Bullion, that the value of the produce o f the fermentation is very far fuperior to the price of the matters employed ; fo that there proceffes may be prefented as obje&s of oeconomy and matter of fpecula- tion.

It is poflibte' atfo to carte& the quality of the grapes by other means, which are-daily pra&ifed. A portion of the muff is boiled in a kettle ; it is concentrated to one-half, and then poured into a vat : by this method the aqueous portion is in part diffipated, and the portion of fugar being then lefs diluted, the fermentation proceeds with more regularity, and the produce is more generous. This'proeefs, almofl always ufeful "in the north, cannot be employed in the fouth, but when the.feafon has been rainy or when the grapes bave not been fuffieiently ripe.

The fame end may be attained by drying the grapes in the fun, Or expofing them for the fame purpofe in f~oves, as i~ pra&ifed in fame wine eountries.

It is perhaps for the fame reafon, always with a view to abforb the moifture, that plafter is fometimes put i~to the vat, as was pra&ifed by the antients.

It fomefimes happens that the muff is both too thick and t o o faeeharine : in that eafe the fermentation is always flow and im~rfe& ; the wines are fweet, lufeious, and thick ; and it ~ not t~ll after remaining a long time in the bottles that

ztto quarts, it

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and the Method of making [Fines. 13

it beeomes clear, lofes its difagreeabte thieknefs, and only exhibits good qualities. The greater part of the white Spanifh wines are in this fituation. This quality of wine has how- ever its partifans, and there are fome countries where the muft is concentrated for that purpofe, in others the grapes are dried in the fun or in ftoves till they are reduced ahnoft to the confiftence of an extra&.

It would be eafy in all cafes to excite fermentation, either by diluting the muff, when too thick, with water, or by agi- tating the vintage in proportion as it ferments : but all this muff be fubordinate to the end propofed to be obtained, and the intelligent agricuhurift will vary his proeett~s according to the effeO: which he intends to produce.

It muft never be forgotten, that the fermentation ought to be managed ~iceording to the nature of the grapes and agreeably to the quality of the wine that may be required. Burgundy grapes cannot be treated like thole of Languedoe. The-merit of the one eonfifts in a peculiar flavour, which would be d'ii'fi- pated by a ftrong and lengthened fermentation : that of the other in the great quantity of alcohol which may be developed in them ; and here the fermentation in the vat mul~ be long and complete. In Champagne, "the grapes deffined for the white brifk wkies are' eollecCted in t|ie morning before the fun has caufed all the moi~ure to evaporate ; and m the fame country the grapes del~ined for making red wine are not cut until they have been well dried by the rays of the fun. In one place artificial heat is necelTary to excite fermentation, in another the nature of the muff is fuch that the fermenta- tion would require to be moderated. W e a k wines muf~ be fermented .in calks, l~rong wines ought to be fuffered to work in the vat. Every country has proceft~s preferibed to it by the nature of its grapes, and it is highly ridiculous to attempt fubmitting every thing to a general rule. 'It is of importance to be well acquainted with the nature of the grapes employed and with the principles of fermentation : Ipv-the help of {his knowledge a fyt~em of conduCt may be formed which eannot fail of being highly ad~ antageous; beeaufe it is founded not on hypothefis but on the nature of things.

In cold countries, where the grapes are very aqueous and little faccharine, they ferment with difficulty- fermentation in that eafe may be excited by two or three principal means :

Ift, By the help of a funnel of tin plate with a very wide tube, which defcends to within four inches of the bottom of the vat, and through which boiling mut~ is introduced into it. Two pailfuls may be ufed for 300 bottles of muff. This procefs~ propofed by Maupin, has produced good effe&s.

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14 On the Cultivation of the FTne,

:~d, By fhaking the vintage from time to time : this motion is attended with this advantage, that it renews the fermenta- tion when it has eeafed or become weak, and caufes it to be uniform throughout the mars.

, g : ~ ,

3 d, By laying a covering not only over the vintage, but round about the vat.

4th, By heating the atmofphere of the place in which the vat fiands.

It often happens that the working of the vintage flaekens, or that the heat is unequal through the mars : it is to obviate there ineonveniences, efpeeial!y in could countries, where they are more frequent, that the vintage is from time to time trod upon. Gentil made two vatffils, of eighteen butts each, and with grapes from the fame vines, and eolle&ed at the fame time : the grapes were freed from the ikins, f~'alks, &e. and bruifed ; the julee of both was perfe&ly equal in quality, and the vintage was put into vats or" equal fize • the weather, but particularly in the morning and at night, was exeeed- inglycold.

At the end of rome days the fermentation began : it was obferved that the centre of the vats was exceedingly Warm and the edges very cold ; the vats were fo eIof¢ as to touch each other, and both. ~xperienced the fitme temperature, They were ~effed down with a long pole. The cold vintage was putlaed f?om the edges towards the centre where the heat was'firongqff: it was-preffed down feveral times, and by there means an equal heat was maintair~ed throughout the whole marl. The fermentation in the vat where this proeefs had been followed was 'finithed twelve or fifteen hours fooner than in the other. The wine was far better, it was more delicate, had a fuperior tar[e, and was more highl'y eoloured and more generous. No one would, have "fakt that it was produced from the fame grapes.

The antients mixed aromatic fubi~anees wi:h the vintage in a ttateof fermentation, in order to give their wines pecu- liar qualities. We are told by Pl'iny that it was ufual ia Italy'to fprinkle pitch and refin o~,er the vintage ut odor vina ¢ontingeret et faporis acumen. In all the works of that period we find numerous recipes for perfuming wines; but thefe different proceffes are no longer ufed. I am, however,, in- clined to think that they were of great benefit. This very- important part of oinology deferves the partieular attention of the agriculturif~. When we confider the cufiom followed in rome countries of perfuming the wines with rafpberries~ the dried flowers of ,the vine~&e, we may even prel~age the happier effe&s from it.

Daree~

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and the Method of raa]ting I/FTnes. 15

Dareet has communicated to me the following fa&s, which ] take the earliel~ opportunity of publiOning here, as they may give rife to experiments proper for improving the art of vinifieation.

" I took," lays he, " a eatk called half a muid, which I filled with the juice of untrod grapes, and fuch as had run of itfelf from the grapes as carried from the vineyard to the prefs : it therefore had very little eolour.

" This eafk contained about 15o quarts. I took about thirty quarts, which I evaporated and concentrated to nearly about one-eighth of the volume of the liquor ; four pounds of eommon'fugar were added,, and a pound of grapes de careme, after care had been taken to brulfe.them : the whole, fomewhat warm~ was then put into the ealk, which was filled up with the fame muff that had been kept apart. A bunch, of about half an ounce, of abfinthium, dried and well pre- ferred, was then put into the eafk, and the eafk was flightly covered, with its lid inverted : fermentation foon took place, and proceeded in a brifk and free manner.

"' Betides this pleee of. muK, I eaufed to ferment alfo a j.'ar of the fame containing about twenty-five, or. thirty quarts, with half an ounce 9f fugar per quart : this wine fermented very well in this jar, and it ferved me for filling up during the fermentation and after the firf~ drawing off,-which wa~ performed at the ufual time~ and repeated a year after: it was afterwards put into bottles at the expiration of a year, or in the following winter.

'" This wine was made in September 1788 , during fine weather, and in a very good year.

" It kept very well even Ira the bottle, it neither became four nor turbid at the end of feveral days ; I have Kill two or three bottles of it: it begins to fade,"

I1, r. Etbiology of Fermentation.

The phmnomena and refults of fermentation are fo highly interefting in the eyes of the ehemiff and the agrieulturif~, that, after" having eonfidered them merely under a prae2ieal point of view, we muff now confider them under the relation of feienee.

The two phmnomena which feem mot~ worthy of attention from the ehemift, 'are the difappearanee of the faeeharine principle and the formation of alcohol.

As in fermentation there is no abforption of air, nor addi. that all changes tion of any foreign matter, it is evi/tent

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16 On the Cultivation of the ~ne,

which take place in the operation can be referred only to the~ departure of thofe fubftances which are volatillfed or precipi- tated.

Thus, by ftudying the mture of thefe fubftances, aM af- eertaining their eonftituent prineiples, it will be eafy for us, to judge of the changes which muft have been produced in the'nature of the firft material~ of fermentation.

The materials of fermentation are the fweet and faeebarine principle diluted in water. This prinei.ple is formed of fugar and extra&ire, matter.

The fubftance volatilifed is the carbonic aeld gas, and that precipitated is a matter an~rogo~as to the ligneous fibre mixed With potaga.

The prineip~l produ& of fermentation is aleohol. It is evideht t~at the tfanfition of the faeeharine principle

to alcohol cannot be conceived but by calculating the differ- ence which muff be produced, in the faceharhae principle by /he departure of the I/rincjpjes that foma carbo~aic acid gas velaieh is volatit~fed, and ttle deJ~afit which is precipitated.

There" principles are, in particul~r, the ca~rbon and the ©xygen : here, then, we ti.nd ea.rbon ard oxygen taken from the-fa,cebarirt~ prineipIe by the progrefs offermematlon i but in p~Qpor&0n, as the faeeharine pnneiple lores its oxygen and its ear, bin, tl~e hydrogen, which forms the third eon- fd, tttent principle, r emainin~ the t~ame, the ehata6iers of the latter element muft predominate, and the fermenting mars mint attaka ~ tb~t point a which it will only pre~nt an inflammable fluid.

In proportion as the aleotiol is developed, the liq~fid ehartges its nature; ~t n~ longer l~as the fame affinities~ nor, cor~tb- quently, the fame dirfolving power. The fmall quantity of extra&ire principle .which remains after having efcapeff de- compofition is precipitated with the carhonat~ of potafh : the liquor becomes clear, and the wine is. made.

Vinous rfCrfia~ntation, then, is nothing but the continued departure of .carbon and oxygen, which produces on one h'/nd:the carbonic ~eid, a~ad on the other alcohol. The ce- lebrated Lavoifier fubje&ed to calculation all: the phaenomcn~ and xeXalts of vinous fermentation, comparing the produ&s of the dcx.omp~o~ion with its, elements. He ~ffumed as the bat~s of his calculations the data furnifhed to him b,y ana!yfis both'in reKard to the nature and-the Woport[olas of the con- ftttuent prtncapl/es bffore and after the operataon. We fliatI here tranfcribe' the refults obtained by this great man.

.Materials

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and the Method of malzing IHncs. 1 7

Materials of Fermentation for a Quintal of Sugar.

lib. oz. dr. gr. W a t e r - - - 4oo o o o Sugar . . . . i o o o o o Yeafi of beer in parle ~ "Water - - 7 3 6 44

compofed o f .~ Dry yeafl: 2, l ~ I 28

Total 51o o o o

Detail of the conjtituent Principles of the dllaterlals of Fermentation.

lib. oz. dr. gr. 407 3 6 44 O f water compofed o f llb. ~z; dr. gr.

I tyd rogen - 6 t x 2 7I"4o Oxygen - - 346 ~ ,~ 44"6o

xoo o o o Sugar e o m p o f e d o f Hydrogen - - 8 o o q Oxvgea - - 6 4 o o o Carbon - 2,8 o o o

~, l~, x ~,8 Dry yeafi compofed o f Carbon - - o I2, 4 59 .00 Azo t - - o o 5 a~'9'~ H y d m g e ~ - - o 4 5 9"3 ° Oxygen - - I I o 2, ~8"76

T o t a l 5 I O o o o

ttecaiOitulation of the conflituent Principles of the 3laterials of Fermentatkn.

lib. oz dr. gr. / ' O f t h e water 34 ° o o o

| O f the water of ! Oxyg . ' { the yeatk 6 2 3 44"6o lib. oz. dr. gr.

| O f the fugar 64 o o o j 4 X x x2` 6 x '$6 k . O f the dry yeaft x to ~, 2,8"76

f O f the water 60 o o o ) | O f the water of

H y d r . { the yeait I I 2, 71"4 9 6 o 8"70 [ O f the fugar 8 o o k O f the yeaft o 4 5 3 ° "

Carb . I O f t h e f u g a r - 2,8 o o o } Of theyeM~, - o I2, 4 59 "x° a8 x2, 4 59 .0o

A z o t o f the yeaR - - - o o 5 ~ '94

T o t a l 5 t o o o o

V o t , . X . B Table

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x8 On the Ouitivatior~ of the ~ne,

Table of the Refuhs obtained by Fermentation. lib. oz. dr. gr. 35 5 4 I9 lib. oz. dr, gr.

O f carboaic ac id , , f Oxygen " - 2.9 7 I ~ 4 compofed o f t Carbon " - 9 z~ ~ ,57

Ot~water, corn- J 0x} 'gen " " 347 ~o o 59 poled of ~ H y d r o g e n - - 6I 5 4 ~7

f Oxygen combined ] w k h h y d r o g e n - 3 x 6 x 64

57 I I x 58 ] H y d r o g e n combined O f dry 'a lcohol , _~ wit~ hydrogen 8

compofed of ] Hydrogen combined 5 5 3 / - w , i t h c a r b o n 4- o _ 5 o t Carbon - 16 xa 5 63

2 8 o o

O f dryaee tou~ ( H y d r o g e n - - o a~ 4 o acid~ compofed ~ O x gen y_ - - I I 1 4 o o f k C a r b o n - ~o I o o o

4 1 4 3 O f f a c c h a r i n e r e - ( H y d r o g e n o 5 I 67

f iduum, eom- "{ Oxygen - ~ 9 7 27 poled o f I - C a r b o n - - I ~ 2 53

I 6 o S a f H y d m g e n - o ~ ~ 41 O f dry yeafi, J 0 x y g e n - o I 3 I : 4

compofed of ] C a r b o n - o 6 ~ S o

t A z o t - . - o o ~ 37

510 0 0 0 ,510 0 0

tlecapitulation of the Refults obtained by Fermentation.

lib. oz. dr. gr. 4 o 9 1 0 0 5 4

Oxygen -

Ca rbon

0

tlb. oz. dr. gr.

i Of the water - - 347 1-o o 59 Of the carbonic acid ~5 7 I 34 Of the a lcohol - 3 I 6 x 64 Of the acetous ac id I I I 4 o O f the faccharine refiduum ~ 9 7 :z7 Of theyeaf~ - - o i3 ~ I 4

/" O f tile carbonic acid 9 ~4 ~ 57 | O f the alcohol - r6 I I 5 63

5 59 ~ O f t h e a c e t o u s a e i & ,- o IO o o - ~ O f t h e f a c c h a r i n e r e f i d u u m I ~ :~-53

~ . 0 f t h e y e a l ~ - - o 6 ~ 3 °

458 6 6 4~ 438 6 6 4L lib.

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ttnd the Method of raaking IVines. x 9

lib. oz. dr. gr. lib. oz. dr.gr. 43'8 6 6 41 Brought over 438 6 6 4Jr

t O f the water - - 61 5 4 ~ 7 |Ofth'e water of the alcohol 5 8 5 3

71 8 6 66 |Combined with the carbon Hydrogen J in the alcohol - 4 o 5 o

Of the acetous acid - o z 4 o Of the f~echarine refiduum o 5 x 67 Of theyeaft - - o :~ :z 4z

o o 2 3 7 Of Azot . . . . o o ~ 37

51o o o o ~Io o o o

By refle&ing on the refutts exhibited by there tables, w~ may clearly fee what takes place in the vinous fermentation : it is firft obferved that, of the ioo pounds of fugar employed, 4 lib. I oz. 4 dr. 3 gr. remained in the t~ate of undeeompofed thgar ; fo that the quantitv of fugar really fubje&ed to opera- tio-n wasouly 95 lib. I4OZ. 3 dr. 69 gr.; that is to fay, 6I lib. 6 oz. 45 gr. of oxygen, 7 lil~. Io oz. 6 dr. 6 gr. of hydrogen, and 261ib. 13 oz.'5 dr. 19gr. of carbon. But by eomparing the quantities it wilt be found that they are fufficient to form all the fpirit of wine, all the carbonic acid, and all the acet- ous acid, produced by the fermentation..

The effe&s of vinous fermentation are reduced, then, to the feparating into two portions the fugar, which is an oxyd ; oxygenating the one at the expenfe of the other to form car- bonic acid ; deoxygenating the other in favour of the former to produce a eombu(dble fubftanee, which is alcohol; fo that, if it were poffibte to combine there two fub~ances, the alcohol and carbonic acid, fugar would be re-formed. It is to be obferved alfo, that the hydrogen and carbon are not in the tkate of oil in the alcohol i they are combined with a portion of oxygen, which renders them mifcible with water: the three principles, oxygen, hydrogen, and carbon, are hei'e, then, ftill in a kind of t{ate of equilibriu~ ; and, indeed, by making them pats through an ignited glafs or porcelain tube, they 'may be re-combined two and two, and water and hy- drogen~ carbonic acid and carbon, are again found.

[To be continued.]

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