MEETING OF THE MIDLAND COUNTIES’ SECTION HELD AT THE WHITE HORSE HOTEL, CONGREVE STREET, BIRMINGHAM,
ON THURSDAY, MARCH 24th, 1927.
Mr. G. C. Evans in the Chair.
The following Paper was read and discussed:—
by W. H. Bufton
The subject of cider is one which is of secondary importance to brewers; still, owing to the growing demand for cider, brewers in increasing numbers are handling it each year, some in cask and others in bulk for bottling.
In the West Country certain brewers have established their own factories, in which they make all the cider they require for their houses throughout the year. The majority, however, purchase the cider they require from manufacturers.
It may with fairness be stated that the increased demand for cider is in a large measure due to improvements in the methods of manufacture, which have resulted in a better article, and of a more level standard of quality. The production of cider by the farmer of 50 years ago was mostly by methods which would not be tolerated to-day. Cider making was often proceeded with regardless of whether the fruit was in the proper state of maturity for crushing or not, just when, owing to. climatic conditions, work in the fields was difficult and employment under cover was required for the hands. The fruit lay about in the orchards for varying periods, and was freely manured by birds and domestic fowls. In some districts it was the prevailing belief that the addition of pond water to the apple juice yielded cider of an improved quality; certainly, as apples are low in nitrogenous matters this addition gave a higher percentage of these, and probably a more vigorous fermentation, but it is difficult to imagine what the final flavour and palate was like. Seldom, if ever, did a farm have steam or hot water in any quantity, therefore, little or no serious attempt could have been made adequately to cleanse the mills, presses, and other utensils. Cider was stored in casks varying from 20 gallons up to 100 gallons, and these were not always kept in a sweet condition. Storage in small casks over a long period allowed too free a contact with air, hence the varying qualities of the cider produced on each farm.
The modern filter was unknown to the farmer, and any attempt to clarify the cider usually consisted of racking or passing it through open bags after adding a fining agent. This entailed a long exposure to air in a contaminated atmosphere, and produced a beverage which could be generally depended upon to become highly acetic and sour long before the next season’s cider was due. The factory methods of making cider to-day, while still being far from ideal, are a great improvement on these very crude methods of the past.
Cider and Perry were according to Latin authors known to the Greeks and Hebrews. They have been made in England for many centuries, though it is difficult to get precise information as to how long, as the term cider formerly meant any alcoholic beverage made from the fermented juice of fruits not necessarily apples.
Not every type of apple is suitable for the production of cider; the kinds which are fit for eating yield a juice which when fermented is mawkish and thin, and does not improve with keeping, while only very few of the apples suitable for cider making are palatable enough for eating. Professor Saintsbury, in his “Notes on a Cellar Book”, sums up the situation neatly in the sentence: “Cider apples furnish one of the most cogent reasons to prove that providence had the production of alcoholic liquors directly in his eye. They are good for nothing else, and they are excelling good for that.”
Only in a few districts in this country are cider apples grown, the soil and climatic conditions not being suitable everywhere. The production in any quantity is confined to Herefordshire, Somersetshire and Devonshire, and a little in Norfolk and the borders of the counties first mentioned. The ideal soil in which to grow the trees is a heavy loam with clay subsoil; light sandy soils produce poor crops of poor maturing qualities. The trees often promise well at the period of blossoming, but the fruit falls off before it is mature. Too high a proportion of lime in the soil produces trouble, but potash is required. The orchard if on a slope should face south and west, so that it can get the maximum of sunshine. The percentage of sugars in the juice is largely proportional to the exposure of the fruit to sunshine during the ripening season.
Unfortunately the cultivation of vintage cider fruit has been neglected to too great an extent for some time post, and many orchards have been allowed to die out. At present the demand for good English cider fruit is barely met by the supply, but growers are now realising that cider apples are profitable to grow, and it is to be hoped that this branch of agriculture will receive its due measure of attention so that the additional fruit required to meet the increasing sale of cider will be produced in the vicinity of the chief factories. Cider makers have been compelled since the war in years of fruit scarcity to go to France and Canada for additional apples to make up the shortage, while they naturally would prefer to use only home grown apples, and the remedy for this lies with the fruit grower, and signs are not wanting that he now recognises this point, and is doing his best to regain the ground lost.
In this connection reference should be made to the excellent work done, both practical and advisory by the National Cider Institute, at Long Ashton, Bristol, under the direction of Prof. Barker. Investigations at the National Cider Institute, extending over a period of 15 years, have proved which particular vintage apples is best suited to varying conditions of soil and climate, so as to produce the finest quality juice and the highest yield of juice per ton of fruit. This knowledge is, and has always been, at the disposal of the cider apple grower, and in addition a large number of young trees of the best types have been cultivated yearly for the grower. The fact that each year’s supply of trees has been barely sufficient to meet the demand proves that the grower is renewing and renovating his orchards. During the last 6 months meetings have been organised in the cider counties with qualified lecturers to advise on all points of fruit culture, and prizes have been offered by cider makers for competition amongst growers to stimulate the interest of the latter. In time, therefore, it is hoped that the supply will be equal to the demand.
Vintage cider apples fall into three main types, Sweet, Bitter-sweet, and Sours, and of each type there are an almost endless number of named varieties. It is not possible to give analytical figures as to the variation in the composition of the juices of these three main groups, as the juice from any single type of apple will vary according to the stock on which it is grown, and the soil in which the stock is planted; moreover a single tree will give varying qualities of juice from year to year. The following will give a fair idea of the difference in these types:—
“Bitter Sweet” and “Sweet” apples, contain more sugar and give a juice of higher sp. gr. than “sours.”
“Sweet” and “Sour” apples contain about the same average amounts of tannin, while “Bitter Sweets” contain more tannin than the other kinds. “Bitter Sweet” and “Sweet” contain lower amounts of Malic Acid than “Sours.”
Cider makers consider that the best ciders are made from a judicious blend of the three chief types of apples. It may be said that the sweet type used alone gives a thin cider of doubtful keeping qualities, a blend of bitter sweet added gives increased body, while the addition of a. proper proportion of sours to the two former sorts gives a sounder cider, with a greatly improved palate, especially when matured.
The problem which the cider maker has to solve is at the commencement rendered more complex than that of the brewer, in that it has not been found possible to sterilise apple juice on a large scale prior to fermentation. Sterilisation by antiseptics is impossible, although it has been .tried in France, by adding sulphurous acid to the fresh apple juice in sufficient quantity to render the natural yeast impotent, and then adding, to the sulphured juice pure yeast cultures which previously had been acclimatised to sulphurous acid. This system got no further than the experimental stage. Heating apple juice to a sterilising temperature imparts to it a cooked flavour, which persists after fermentation; moreover, the heating precipitates some of the already too scarce proteins and profoundly affects the degree and rate of fermentation.
Attempts have been made to inoculate the fresh apple juice with heavy additions of selected pure yeasts, but almost invariably the yeasts natural to the juice become dominant after a short time. This result possibly may be due to the scarcity of available protein. Pasteurising the apple juice and inoculating it with pure yeast cultures has been tried in the laboratories of some makers, and at the National Cider Institute, but it is not yet being done, as far as I know, on a commercial scale.
My experience has been that by purchasing fruit over a long period of years from the same orchards and studying the idiosyncrasies of the yeast flora developed from this fruit in the particular conditions under which the factory is run, a standard of flavour has been obtained and maintained, and this, provided that the flavour and palate developed are to the liking of the public, goes a long way towards building up a sound business. The experience of most of the larger cider makers is that a fairly definite flora is maintained year after year, due to the standard conditions of manufacture.
While the cider maker cannot sterilize apple juice before fermentation he can and generally does one thing which is essential if a sound cider of clean palate is to be obtained, viz., thoroughly wash the fruit before it reaches the mills. Considerable ingenuity has been displayed in designing mechanical apple washers, which will effectually cleanse the fruit, the main principle in the various types being thoroughly to scrub the apples, loosen and remove any adhering dirt, and to spray them before they are elevated to the mill floor. This washing of the fruit besides removing any adhering dirt has marked effects on the fermentation. The flora developed in the juice from washed and unwashed fruit differs considerably. With unwashed fruit a much larger proportion of the apiculatus type of yeast is found, and it can only be assumed that this type is more easily washed off from the apples than the S. cerevisiae. Again, this thorough cleansing helps to keep down acetic bacteria, the cider maker’s natural enemy. However sound the fruit is, in the course of grinding large quantities there are sure to be some damaged apples, and one of the first things which happens when the skin is broken is that yeasts ferment the sugar, and acetic bacteria attack the alcohol as it is formed. In the washing process the rotten apples sink, and are washed away in the water. The juice resulting from well washed fruit has, if properly handled in the fermentation and storing, every chance of producing a clean cider, whilst that from unwashed fruit is almost bound sooner or later to become acetic. The washing considerably reduces the number of yeast cells in the raw juice, and consequently the first fermentation is slower in starting, and steadier when in progress, which is a material point in improving the flavour and assisting the filtration.
The type of mill most in favour at present does not crush the apple in the way the old stone mill did, but it grates the fruit fairly finely, so that the cells are torn apart as much as possible, and in consequence the juice is more readily given up under pressure than if the apple was merely crushed. These grater mills consist of a revolving drum carrying in slots a dozen or more knives with corrugated edges, each one projecting about 1/16 in. above the level of the drum; this drum is driven at about 2,000 revolutions per minute, and the apples falling into the hopper above are held against the revolving drum by counter weight concaves. Each mill of the type is capable of grinding about 20 tons of apples in an eight hour day.
The grated apples fall from the mills into a container below, the outlet of which is fitted with a shutter, allowing the crushed apple pulp to be let out as required. Immediately below this container are built up what are known as “cheeses” for pressing the juice from the crushed apple. They are made as follows: A large wooden tray on a trolley, which runs on rails, has placed upon it an open rack, consisting of crossed strips of wood—the rack being slightly smaller than the tray, and over this rack is spread a large specially woven open mesh cloth. A quantity of the pulped apple sufficient to cover that portion of the cloth immediately over the rack is let down on to it, the sides of the cloth are folded over so as to cover the pulped apple, and another rack is placed upon it, and another cloth on this, which cloth then receives its quantum of apple, and so on until a cheese of about one dozen or so cloths of apple and separating racks is built up. The use of the wooden racks is to form small channels wherein the juice from the centre part of the cheese, may flow away. This cheese is then pushed along the rails on its trolley under one of the presses where it receives a pressing of half an hour or more. The presses are usually worked by hydraulic power and different makers press to different extents, but with big presses and powerful hydraulic pumps working up to 4,000 lb. to the square inch, giving a pressure of 250 tons or so on the cheese, very little juice is found to be running from the cheese after half an hour’s pressing, in spite of the fact that the pressed residue remaining under the press will contain upwards of 70 per cent. moisture.
If this pressed residue (technically known as pomace) is taken from the cloths, broken up and built up into a fresh cheese, and again pressed, a further quantity of juice can be extracted. A second pressing of 250 tons or so for half to three-quarters of an hour will reduce the moisture in the pomace to about 65 per cent., and below this it is hardly profitable to press. With two pressings about 165 gallons of apple juice per ton of apples can be obtained.
A method of extracting the juice more completely, which is practiced in France, and to a small extent in a modified way in England, certainly gives an increased yield of juice. It is worked somewhat on the lines of the diffusion process for the extraction of sugar from beet. The apples are milled differently, being sliced rather than grated; batteries of ten or so small vats of 150 gallons or more capacity according to the size of the plant are filled with the sliced apple. Water is allowed to flow in to the top of No. 1, the bottom outlet of which is connected to the top inlet of No. 2, and so on through the series. As the diffusion proceeds the juice is collected from the bottom of No. 10, and when after a time No. 1 is exhausted, and only very low gravity liquid flows from it, the contents are emptied out and the container filled with freshly sliced apple. No. 2 container then becomes No. 1, i.e., the water is now turned on to No. 2, and the freshly filled No. 1, No. 10, and so on. To run this system successfully continuous work night and day must be carried on. While this system can and does give an increased yield of cider owing to the more complete extraction of the apple tissue, it cannot, worked alone, give a pure juice cider, and there is a risk of producing harsh acid cider owing to the long exposure to air of the crushed apples and juice which stimulates any acetic bacteria present. A modification of the process consists in first pressing the apples, and collecting the pure juice for the first quality ciders, then diffusing the pressed pomace for its complete exhaustion.
To return to what may be termed the standard method of cider making, the juice as it leaves the presses flows into a container from which it is pumped into the fermenting vats; the freshly expressed pure juice will have a sp. gr. of from 1044° to 1056″, occasionally rising with very good fruit to as high as 1060°, the average of a good year will, however, be from 1048 to 1050° The sp. gr. is a quick and accurate measure of the richness of the juice in sugars, and in factory working it is almost entirely depended upon as an estimate of the quality of the juice. The sugars contained in apple juice are cane sugar, glucose, and lævulose. The proportions of these sugars vary, but generally cane sugar does not exceed one-quarter of the total sugars, glucose seldom exceeds one fifth, while lævulose is seldom less than 60 per cent., and may rise to as high as 90 per cent, of the total sugar. The percentage of total sugar in apple juice while varying greatly from season to season and with different apples will generally be between 10 and 14 per cent.
The acidity of apple juice is due to malic acid and ranges from 0˖2 per cent, to 0˖3 per cent, in “Sweet” and “Bitter Sweet” juice, and to as much as 0˖6 per cent, or 0˖8 per cent., and occasionally even higher in the juice from sour apples.
The tannin of apple juice which has yet to be thoroughly investigated differs from gallo-tannic acid, and appears to be more closely allied to the tannin of catechu, and coffee: it gives a green colour with ferrous salts, a reddish brown with caustic alkalis, and precipitates vegetable albumins and gelatin. The amount found in apple juice varies from 0˖1 per cent, to 0˖3 per cent, in “Sweet” and “Sour” fruit to 0˖3 per cent, to 0˖6 per cent, in “Bitter Sweet” juice.
Clean sound apples contain only a small amount of nitrogenous matter, and this has a distinct bearing on the rate and degree of attenuation. The average content of nitrogen being about 0˖01 per cent, and according to Warcollier (Ciderie et Pomologie) only one half of this is assimilable by yeasts. Fermentation commences slowly—in about 3 to 4 days after pressing, but, of course, it may be quicker or slower according to the temperature of the cellar. On an average, the sp. gr. will have fallen to from 1025° to 1030° in about 14 days, and at this point the first filtration is usually done in order to steady the fermentation. Some makers prefer the cotton pulp type of filter, others the plate and frame with cloth, but each has its use in the cider industry. Whatever filter is used it is essential that it be constructed of such material or in such a way that the cider can pass through it without contact with iron during filtration, or a darkening in colour will result, due to the interaction of the apple tannins with the iron dissolved by the malic acid. This trouble may not be apparent at the time, but it will show up to a greater or lesser degree after the cider has been exposed to the air for a time, and while there may be only very little deterioration of flavour, no one would care to drink cider which gradually assumed the appearance of diluted ink. While ciders of high malic acid content will naturally attack iron more readily than those of low acidity the blackening will be more marked in those of low acidity, the explanation being that malic acid tends to break down the weak combination of iron and apple tannin, and, therefore, although ciders of high natural acidity may contain appreciable iron it will not be so likely to cause trouble as if the acidity is low.
Mention may be made of what is undoubtedly a frequent cause of the production of inferior cider. When the cider has been filtered the yeasts remaining in it are few in number, and because of the low nitrogen content are comparatively inactive. Thus, little or no carbonic acid is evolved, and if owing to unclean methods of manufacture invading organisms such as acetic bacteria have been allowed free access to the apple juice during the making period, an excellent opportunity (which has not occurred before owing to the yeast activity) is presented to them to increase and multiply, and incidentally convert what should have been cider into a mixture of varying proportions of cider and vinegar. The two things essential in preventing this acetic cider are strict cleanliness and storage free from contact with air. If these are carefully observed, and only sound, well-washed fruit is crushed, there is no reason why the total acetic acid in cider should exceed 0˖075 per cent., and with the best ciders it should range between 0˖03 per cent, and 0˖05 per cent.
Bottlers of cider would be well advised to examine carefully in their laboratories samples of cider on offer before purchasing, and in doing so the following points should be noted:—
(1) Flavour and appearance. (2) Original gravity. (3) Present gravity. (4) Percentage of malic acid. (5) Percentage of volatile acidity. (6) The amount of sulphurous acid and the prcsence of any other preservatives.
- Flavour, palate and bouquet are, of course, of first importance; there should be no suggestion of vinegar when warmed, and the palate should be distinctly apple like. The cider should be brilliant, and it should not darken on exposure to air for an hour or two.
- If the original gravity is lower than 1043° to 1044° dilution of the original apple juice may be suspected. Obviously from season to season, and during the same season from one district to another the richness of apple juice will vary, but it seldom falls below the figure previously mentioned except in possibly a few isolated instances of very poor orchards.
- Should the present gravity exceed 1018° to 1020° for a sweet cider, and it is to be naturally conditioned heavy deposits may be expected before the cider has been sold; if the cider is to be chilled and carbonated for a quick sale there is not the same risk.
- When the percentage of malic acid is below 0˖30 per cent, the cider is somewhat liable to an attack of sickness, especially if the sp. gr. is high, and in any case it will probably not be of a good flavour when conditioned. If above 0˖5 per cent, or 0˖6 per cent, the flavour will remain harsh unless stored for a considerable time.
- If the percentage of acetic acid is higher than 0˖075 per cent. “floaters” will in all probability make their appearance at an early date after bottling, and the flavour and bouquet will be damaged.
- The total sulphurous acid must not exceed 200 parts per million to comply with the Preservatives in Food Regulations, and no preservative other than this acid must be present.
In the past it was a common practice on the part of some cider makers, and possibly brewers, to “sulphur” their casks before filling by either washing them out with calcium bisulphite solution or burning a sulphur match in them. A sample of cider which contained 100*l parts per million of SO2 estimated by the official method (gravimetric) was filled into two casks, one of which had been sulphured by burning a aulphur match in it, and the other washed with hot water. A few hours after filling the casks samples were drawn from each, and the content of S02 was espectively 100*1 part and 201*5 parts per million. It is, therefore, necessary to avoid the use of sulphured casks for cider storage.
As to whether cider in bottle should be chilled and carbonated, or naturally conditioned, there is much the same division of opinion as exists among brewers with regard to these two treatments of beer. While the writer believes that no artificial carbonating can give the same palate to cider as natural conditioning in bottle, it must be admitted that for certain classes of trade chilling and carbonating has much to recommend it, and certainly the public are prone to judge a cider to be good if it pours out brilliant with a brisk disengagement of gas before it is raised to the lips. Probably, as much bottled cider is carbonated as is naturally conditioned. Bottles are frequently not filled sufficiently full, and an air space between the surface of the cider and the bottom of the cork of from 1½ in. to 2 in. in the bottle neck is often found. This air space should never exceed ½ in. lf it does, there is always a risk of acetic action due to stimulation of the bacteria by the air absorbed. This fault is particularly prevalent with crown cork users.
In bottling cider for natural conditioning there is always the possibility of competition between the yeasts and any acetic bacteria present as to which shall get the upper hand. Frequently, brilliantly filtered cider which had in its first fermentation a very vigorous yeast growth is deficient in available nitrogen, and, therefore, if any acetic bacteria are present and these have the natural stimulus of a good oxygen supply, they are prone to dominate the partially starved yeasts. This point is covered if the cider is carbonated, and is one of the chief reasons in favour of that process.
Particular care should be exercised by a brewer who bottles cider to see that all bottles are well cleaned, and free of any deposit, and the bottling machines also should receive a special cleaning when used for bottling cider after having previously been used for beer. The reason for this is that on many occasions when complaints of poor flavoured cider, bottled by brewers or bottlers, have been made, upon investigation the trouble has been traced to contamination with beer yeasts, which could only have come from imperfectly cleansed bottling machines or bottles. It is extraordinary what a large volume of cider can be given a beer flavour by a slight contamination of this type, and unfortunately the flavour is not fully developed until the cider has got into condition, and so a loss is caused which, with sufficient care, could have been avoided.
At this point it will be convenient to return to the manufacture of cider. After the first filtration, the new cider, now quite bright passes from the filters into the storage vats. These will be of varying capacity, according to the size of the factory, and the lines on which the various makers work, but the general tendency in recent years is to build vats of increasing size. For one thing, the larger the vat, the greater the economy of space, and the smaller the proportionate cost. Again, there is a smaller surface of cider exposed to possible contamination. At the same time vats of practically any size have their uses in the cider industry, and if a round of visits were paid to the leading makers a range of sizes of from 1,000 to 60,000 gallons would be found. In France cider makers favour glass lined reinforced cement tanks rather than vats, but these have not found many users in this country. In the storage vats the new cider is matured, and later blended, and in the latter process a series of vats of good capacity is of great service in enabling large quantities of identical cider to be offered, which if stored in small vats would often develop differences of palate, although apparently the same at the filtering stage.
As the storage vats are filled with the filtered ciders, samples are drawn off, placed on the forcing tray for 14 days or so, the acidity (fixed and volatile) and percentage of alcohol determined, and the deposit examined microscopically. The information obtained is of assistance in blending the various vats and in deciding which ciders are best for bottling, and which must be sold as draught, and in addition early information of possible trouble is obtained. Possibly the most feared of these is cider sickness which is due to an organism whose natural habitat is thought to be on the apple, or the tree. When a cider is attacked by sickness an active fermentation takes place, if in bottle sufficient often to burst a large number. The cider becomes very hazy in appearance, much as if a teaspoonful or so of milk had been added to a pint, partly due to the formation of a considerable amount of aldehydes. The cider is rendered unfit for sale, although if stored for a considerable time the unpleasant flavour developed will be gradually lessened. Fortunately, this organism is very sensitive to acidity, and a cider containing from 0˖35 per cent, of malic acid upwards is seldom attacked.
Whilst this paper is concerned with cider it may be of interest to refer briefly to perry. The consumption compared with cider is very small, due largely to the fact that the cultivation of perry pears has been neglected, and as pear trees have become old they have been replaced by apples, it is consequently difficult now to get adequate supplies of the proper pears for its manufacture on a large scale. There is an old proverb which runs, “The man who plants pears plants for his heirs,” meaning that a long time elapses before the trees bear a crop of fruit,[and this probably is the real reason for the decline of pear culture. Perry made from the best vintage pears is a most delightful beverage. Pear juice is of a higher sp. gr., and contains a higher percentage of sugars than apple juice, and in consequence perry has a higher alcoholic content than cider. The acidity is also somewhat higher. When naturally conditioned in bottle perry distinctly resembles a mild champagne, and it is a pity that adequate supplies of good pears for a large production of perry are unobtainable, because if they were, perry would find a market with many people who find cider too light a beverage. The tissue of perry pears is quite different to that of cider apples, being more easily pressed, the crushed fruit, too, yields its juice more readily than apples, but the yield of juice per ton of fruit is about the same as an apple. Another point of difference is the more rapid ripening of pears as compared with apples, and it is essential to crush and press pears within a few days of picking or they will quickly rot. They are more difficult to wash than apples, being heavier than water, and different washing apparatus has to be used. The after treatment of pear juice for making perry is similar to that followed in cider making.
Cider can only in a small way compete with beer, as in the first place there is only a limited quantity of suitable apples available for its manufacture, and it is unlikely that the individual who is a regular consumer of beer will change his beverage to cider; there are, however, a growing number of people who formerly drank foreign wines, but because of the present high cost of these are replacing them with bottled cider, and it is to this class of person that the higher grades of bottled cider appeal. It is to be hoped that those brewers who bottle cider in order to meet this demand will satisfy themselves that they are bottling a good class article, and that they will bottle it well. As in their own specialised art of brewing their care and attention will be well repaid.
The Chairman pointed out that the chief trouble of the cider maker was the variation in material, and the juice could not be sterilised prior to fermentation. It seemed to him that the problem of the sterilization of apple juice should be capable of solution. Mr. Bufton had mentioned the lack of nitrogen in the juices, but would it not be possible to add easily assimilable nitrogen to the apple juice, so that the subsequent fermentation could be regulated to a greater extent than it was at present. The fermentation of apple juice and malt wort ran to a certain extent side by side, although the brewer employed a yeast which was composed of very few elements, whereas the cider manufacturer had to deal with at least fourteen different types of yeast, and probably more.
Another point with regard to cider manufacture which impressed him was the waste of raw materials after the crushing process. Could not some use be made of it for the manufacture of vinegar? The dark colouration of cider on exposure to air was most likely the result of enzymic action. His personal opinion was that no carbonated beer ever touched natural conditioned beer, and it was the same with cider. The demand of the British public to-day was for a brilliant beverage. It was looked at first, and tasted afterwards, and the taste was in many cases a secondary consideration. He would be glad to hear if Mr. Bufton could tell them anything on the subject of champagne cider.
Mr. F. Maynard said he understood that Mr. Bufton stated that glass-lined concrete tanks had been used, and that they were unsatisfactory. He would like to know the reason. Was it the joints between the glass tiles? Was there any objection to the use of aluminium vessels?
Mr. R. H. Evans asked what average price apples would make on the market, taking into consideration the variation of seasons; and what was the return per acre. He would also like to know whether Mr. Bufton had carried out any experiments to ascertain whether an improvement in flavor in cider resulted from the addition of malt wort.
Mr. R. J. Crowe enquired how the corks used in the bottling of cider should be treated. Should the bottles be dry or freshly washed?
Col. J. H. Collett said that in the Midlands cider did not interest the brewer so much as in Gloucestershire, where so much cider was drunk in the licensed houses that certain brewers had found it necessary to run their own cider factories. Probably a larger amount and a better quality of perry pears were grown in Gloucestershire than elsewhere, and he claimed that Gloucestershire perry was renowned throughout the country for its good characteristics. The author’s statement about sulphurous acid showed how necessary it was, both for the brewer and the cider manufacturer, to be accurate in the amount of sulphur dioxide used in their casks whether added by means of bisulphite or burning sulphur. With regard to the clarification of cider, the author only mentioned filtration, but there were methods of clarifying in cask. It would be interesting to know which was considered by the author to be the most efficacious way.
Mr. J. A. Lones said the thought had occurred to him that in the initial process of washing it might be possible not only to wash the skin of the apple, but as a further precaution against contamination to peel mechanically the apple and then wash again. He imagined that the spores and undesirable ferments were more or less contained on the outside of the skin and perhaps peeling the apple would get rid of a great deal of this undesirable contamination. He gathered that the natural ferments of the apple juice were in contact with the skin of the apple, and it might also be that the skin played an essential part in flavouring and, therefore, his suggestion might be impossible in practical working. During the process of crushing the apples the juices were in direct contact with the air and were in that sensitive condition when they would perhaps be infected with injurious organisms very readily. He would like to know whether filtration of air was a practical question in a cider factory, if so it might afford a means of eradicating a certain amount of undesirable contamination. Concerning the waste material which had been mentioned, it would be interesting to know whether that juice could not be recovered by centrifugal machines and whether centrifugal separation of the juices had ever been tried in a cider factory. On the subject of casks he would like to ask if one particular kind of wood was necessary for cider cask or whether cider manufacturers had a larger field of choice. He would also like to know what means were taken to sterilise casks and whether it would be economical to install any of the mechanical methods which the brewer employed.
Mr. A. M. Craven Smith asked whether the cider with the highest gravity was the bcst quality. Further, supposing a quantity of cider was purchased and taken in several deliveries, would the original gravity of each of the consignments be the same. It would be of interest to know how long cider should be kept in cask after receiving it before it was bottled, and how long it should be kept in bottle before being distributed.
Mr. G. Seligman said he was not quite sure whether the cider manufacturer relied on the yeasts already present on the apples or whether it was necessary to add yeast. If yeast had to be added was the cider maker’s problem in any way as intricate as the brewer’s in preserving the purity of his yeast?
The Author, in reply, said that he did not think nitrogenous foods were being used to assist fermentation, though in isolated cases they might have been. If cider stopped fermenting at too high a gravity, a little nitrogen helped matters. In the main, however, it was not difficult to get cider to ferment as far as was required. Although it was true that there had been great waste of raw material in the past that was no longer the case. The war-had taught them to make use of apple pomace, and it proved to be a good cattle food, containing rather more than 50 per cent, of carbohydrates when dried. Experience had shown that this country would not have apple vinegar. As regarded the darkening of cider, while the remarks he made were correct, he might add there was also an organism which had been isolated and which was directly responsible for the darkening. Although the darkening was due to the interaction of tannin and iron, the organism in question reduced the acidity of cider and by reducing the acidity below a certain point, caused the iron present to show up. He regretted to say that a great deal of the so-called “champagne cider” was not made on the same lines as champagne. There were several firms making glass-lined tanks. They were made first of all with reinforced concrete, on the face of which were fixed small blocks of glass, and a so-called secret preparation was spread in the spaces of the glass lining. The tanks were very expensive. They had been tried by several makers, one or two of whom said they liked them. For the most part, however, the English cider manufacturers relied upon oak vats. It was possible that aluminium might be largely used at a future date in the cider industry, but at the present moment it was in an experimental stage. They had a rather more difficult problem than in the case of beer because of the action of acetic acid. More than one firm was collecting and using carbon dioxide quite successfully. There was no question that cider apples were profitable to grow at the present time. Since the war apples had seldom been less than £5 a ton. Last year the price was £6 and the year before £5 10s. The yield of apples was about 8-10 tons to the acre on an average. The return was, therefore, not unsatisfactory, especially when it was remembered that the farmer did not expend much labour on the trees. The picking ought to cost 10s. a ton, sometimes it was done for less. He had never tried the addition of a malt wort to cider, but he knew it had been done. The process had been patented, but whether it was going to be successful or not, he did not know. He liked corks which had been impregnated with wax as they were cleaner and more likely to be sterile. He used them wet, having moistened them with a half per cent, solution of hypochlorous acid. Formerly dry bottles were used, but seldom now. So long as the bottles were clean he did not think it made any difference! With regard to clarification other than by filtration, he believed some makers used gelatine or isinglass successfully as fining agents. The point made about peeling the apples might be developed, provided the necessary machine could be obtained. If the fruit was peeled virtually a sterile juice would be obtained provided that there was no unsound fruit present. As the skin of an apple contained quite an appreciable amount of oil and wax the flavor might be affected. He did not know to what extent, but he was inclined to think to a marked degree. To the best of his knowledge air filtration had not been tried and he could see very considerable difficulties in the way of doing so. The firm he was associated with had made many experiments to ascertain whether it was practicable to obtain a greater extraction of the juice by centrifugal means, but after centrifuging the fruit with a fairly efficient machine there was still about 80 per cent, of moisture remaining. Oak was the only wood that was used by the cider manufacturer for casks. For the purpose of sterilisation, it was a practice to coat the inside of the cask with hot melted paraffin or a suitable enamel. With reference to the relation of sp. gr. to quality, generally the higher the original gravity the higher the quality. He advised the bottling of cider at the earliest possible moment after delivery. Cider of a gravity suitable for natural conditioning did not improve in cask; in fact, the reverse was the case. Obviously there was infiltration of air through any wood, and secondary fermentation that ought to take place in the bottle might commence in the cask. With regard to how long cider should be kept in bottle before being sent out, a great deal depended upon the temperature of the cellar and the cider itself. Naturally conditioned cider was not fit to send out under a month. Personally, he preferred three or four months as a minimum. They did not add yeast for fermentation, depending on those already present.
A vote of thanks was accorded the Author for his interesting paper.