IT is curious that the public should hold opinions with regard to the production of the various cheeses having blue or moulded veins within, which are entirely unwarranted by the facts. I refer to such varieties as the Gorgon­zola of Italy and the Stilton of this country. It is supposed by some that Gorgonzola, for example, is the product of goats' milk, or of the milk of the goat blended with the milk of the cow; and by others that the blue mould is introduced by the insertion of metal skewers, which, by the way, are sometimes used, and used, too, for the purpose indicated, although the result is achieved in a very different manner from that supposed. The blue mould of cheese is the common Penicillium which attacks bread and other materials common in the household. It is probable that it is abundant in every apart­ment of a house, and nowhere more so than in the dairy where cheese is made. If we regard the mould as a plant, and that plant as a weed, we shall better understand the principle which is followed in its extensive production by remembering that as the seeds of weeds are more prolific in the production of plant life when they fall upon fertile soil (such as the well-tilled and well-manured arable land of the farm) than when they fall upon the highway, so does the tiny plant which we call mould increase with great rapidity when it alights, as it were, from the atmosphere upon curd, which to it is a most fertile soil. It grows, elaborates its seeds or spores, which in their turn are shed abroad, falling upon similarly fertile soil, the curd of other cheeses, ultimately covering the portions in which they are permitted to grow.

GORGONZOLA. — Gorgonzola cheese is made from average cows' milk of the northern part of Italy, in which country I had the advan­tage of learning a great deal about the system. The cows' milk of Lombardy, to which reference is chiefly made, is not so rich as is generally supposed, but it is not absolutely essential that the milk intended for conversion into Gorgonzola or Stilton cheese should be specially rich in fat. To a very large extent this milk is produced by small owners of cows, who manufacture the cheese, but do not perfect or ripen it, selling it to merchants for this purpose, who in their turn finish the process in the cellars and caves which they own. Gorgonzola is a cheese which is produced from two curds, that is to say, from two lots of curd made at different times. When the two curds are put into the mould which gives form to the cheese, one is cold and stale and the other warm and fresh. For example, assuming the cheese to be moulded in the morning, the milk of the evening previous having been brought to a temperature varying from 80° to 85° F., and in some cases 90° F., the rennet is added. It is important, however, to make one or two remarks at this point. In dairies which are conducted upon defined principles the temper­atures adopted are systematically arranged in accordance with the weather; but large numbers of small farmers who have no dairies worthy the name, add the rennet to the milk just as it comes from the cow, so that the temperature may vary from 90° up to 93°. Again, the rennet generally used in Italy is a filthy preparation which is, practically speaking, the macerated stomach of the calf, the actual animal matter itself. A portion of this material is placed in a piece of cloth and dipped with the left hand into the milk, the right hand the while squeezing it in order that the extract which exudes may be mixed with the milk, which is subsequently stirred. In Italy the curd, when fit for cutting or breaking, is gently broken with an instrument called a paumarilo: the operation lasting about a quarter of an hour. The whey is gradually expelled until the curd is fit to be hung up in a cloth on to a hook in the ceiling, and there left until the following morning. It is essential that the apartment in which it hangs should be at least 60°, but not more than 65° F. If higher, it may become too dry; if lower, too heavy, the whey not leaving it properly. Naturally, however, difficulties are met with by the small dairymen in the mountainous districts, especially those who are constantly moving with their herds of cattle, and therefore compelled to make the cheese wherever they may be; this system it is which accounts for so much inferior Gorgonzola.

The curd of the morning is in the first place treated in a similar manner to that adopted with the curd of the evening, but when broken every effort is made to obtain from it a large quantity of whey while it is still warm. A small quantity of acid forms in the evening's curd, but the curd of the morning should be perfectly sweet. The mould used in the manufacture of Gorgon­zola is a curled piece of wood, preferably beech; but in some cases metal is being introduced in consequence of the fact that it can be more easily cleaned, not absorbing the whey, as is the case with wood. To one end of the mould a cord is attached, so that the cheese may be tightened or loosened as may be found desirable. When ready for moulding the curd is placed on the draining-table, which is fluted to carry off the whey, and the mould is placed on a rye-straw mat. Sometimes the mould is divided into two parts, the upper portion fitting into the rim at the head of the lower portion, and being removed when the curd sinks. Before filling, the mould is lined with a strainer cloth. In commencing, the bottom of the mould is covered with a thin layer of the warm morning's curd. Above this is placed a layer of the curd of the previous evening, followed again by another layer of warm curd, and so on until the top is reached, care being taken that the warm curd covers the entire surface of the cheese. The prime object, as I believe, of thus alternating the two different kinds of curd is that the mould is enabled to grow in the inter­stices which are formed, inasmuch as the warm and cold curds never unite in the same close, homogeneous manner as is the case where the curd is all made from one lot of milk, and is all of one temperature.

MOULD-RIPENING. — In different countries different methods are followed for the pro­duction of the mould. For example, in that part of France where the famous Roquefort cheese is produced from the milk of the ewe, the makers do not rely absolutely upon its natural growth, but they specially prepare a kind of bread, which is crumbled, and upon which mould is induced to grow, which it will easily do by exposure to a slightly warm, humid atmosphere. The mouldy crumbs which are thus produced are mixed with the curd, which is subsequently converted into cheese.

After the cheese has been formed it remains for drainage in an apartment at about 66° F. It is frequently turned, taken out of the mould, the cloth changed, and turned again. In Lombardy, where the cheese is sold in its new or green form, it is weighed at the time it is last taken out of the mould. It is then ready for removal to the salting-room, where it subsequently remains a few days at 68° F. The cheese will then be found covered with a fine growth of white fungus, which is an indication that it is ready for salting. The finest salt is used by the best manufacturers, although those who exercise little care use any salt which comes to hand. The surface of the cheese is entirely covered by gently sprinkling, the salt being subsequently rubbed into the crust with the hand. As a rule, this method of salting continues daily for a considerable period, from two, to four weeks; but in some cases the upper portion of the cheese is salted at one time and the lower portion at another, that is, on the following day, so that the entire cheese is really salted from twelve to fifteen times. When this process has been completed, the texture of the cheese may be examined. If it is too close, it is possible that the fungus or blue mould will not grow with freedom. In this case the cheese is pierced with metal skewers, which admit the air, and with it oxygen, which the fungi require, for they are unable to grow in its absence. Should the texture, however, be sufficiently light and generous, nothing need be feared, as it will grow equally as well as in the Stilton, in which the texture is generally closer and mellower.

When Gorgonzola cheeses are taken to the cave to ripen — and some of the Italian caves which we have been enabled to see are very fine and well arranged — they are laid upon shelves covered with rye-straw and kept at a temperature of about 55° F. As with other cheeses, ripen­ing can be hastened by a rise in the temperature, but the best cheese is that which is produced during the process of a longer time, and at a lower temperature. During the ripening process, which may take as long as from four to five months, or even more, different varieties of fungi grow upon the crust. The first to appear is a fungus of a dark colour, which is followed by a white mould, and subsequently by a red fungus, which is supposed to give colour to the cheese, although this colour is generally simulated by artificial means. The best Gorgonzola is of a very high type indeed, but it is seldom seen in this country.

STILTON. — The leading blue moulded cheese in this country is the famous Stilton, and the system adopted in its manufacture is not unlike that which is followed in Italy in the manufacture of Gorgonzola, or in France in the manufacture of Roquefort and several other varieties of a similar character. Stilton is the leading cheese of a class which in this country includes the Wensley­dale and the Cotherstone, both of which when really perfect are varieties which it is difficult to beat; indeed, a perfect Wensleydale, with its mild flavour and mellow texture, is scarcely equalled by a perfect Gorgonzola, and I am not sure, although Stilton is made in my own dairy, that this more famous variety can at its best equal either of those named at their best. It is, however, fair to say that perfect cheeses of either kind are much less often seen than is the case with Stilton, in the production of which very considerable skill is now brought to bear, the industry being one in which there is keen competition, and which, in consequence, it is to be feared, will in the future yield lower prices to those who produce this cheese. There are different methods adopted in the production of Stilton, which it is proverbially supposed can only be manufactured with success in Leicester­shire. This, of course, is fallacious; but there is a great deal in Leicestershire herbage, if not in Leicestershire cattle or climate. A method which will be found successful is that of setting the morning's milk at 85° F., and removing the curd in thin layers at the end of an hour into the draining-cloths which are laid upon a properly constructed draining-table. It should be observed, however, that in no case is it possible to lay down definite figures for all cases, whether they relate to temperature, time, or the quantity of rennet used. The quality of the milk and the climate of the district have considerable influence, and these influences must be met by a slight deviation either in the temperature at which the milk is set or the quantity of rennet added, to say nothing of one or two subsequent details. The curd then is placed layer by layer into the drainers. Here, being warm, it gradually parts with its whey, and as it becomes firmer the corners of each cloth are tied loosely together, in order that the slight pressure thereby exerted may cause the whey to leave it still more effectually. These corners are from time to time tightened until the curd is fairly firm, and can be handled without breaking into pieces. When the temperature of the air is about 60° F. the curd may be generally left throughout the night, but when the temperature is below 60°, the curd had better be slung in a cloth from the ceiling, as suggested with regard to the Gorgon­zola. In this way the curd parts with its whey more freely. On the following morning it may be removed, cut in cubes, and laid in an open shallow tin vessel to air. Airing is a somewhat indefinite term, but it may be mentioned that the object is to create or increase acidity in the curd. There can be no acidity without contact with oxygen, and as the air contains oxygen, so the curd is aired.

The morning milk is treated in a similar manner, and sometimes on the evening of the day on which this curd was produced it may be placed within the mould, but it depends upon its condition, for it must not be broken up for moulding until it is sufficiently firm and ripe, more particularly if the weather is cold, as in this case the cheese would swell and be utterly spoiled. On the second day, however, it is always possible to mould. The mould used is a cylinder slightly larger in diameter than a Stilton cheese itself. It is perforated with a number of rather large holes, through which a certain quantity of the whey exudes when the curd is within it. The mould is placed upon a cloth and is gently filled by the hands with the mixed curd of the two milkings. At this time the earlier curd is distinctly acid both in taste and smell, and also silky and mellow. Before mixing, both curds are broken into fine pieces with the fingers as gently as possible, and, after weighing, mixed with a fair proportion of salt. It is salted curd, therefore, of which the cheese is made, and in this particular, as well as in others, it differs from the Gorgonzola process. Both top and bottom of the cheese are carefully finished off so that the edges are cut clean and the surface level. In the course of three or four days, should the tempera­ture be maintained at from 60° to 63° F., the cheese will be firm, and will have left the sides of the mould, which may be lifted from it, allowing it to stand alone. It is now bound with a calico binder somewhat tightly, and pinned top and bottom. This bandage is removed and a clean one put on every day until the somewhat wrinkled coat of the cheese has partially formed. It is then taken to the drying-room and subsequently to the ripening-room.

All cheeses of this character lose con­siderably in weight, in spite of the fact that they are not pressed, and yet they maintain a mellower, softer, creamier texture than cheeses which have been pressed. It is possible to hasten the process of ripening: first, by drying the cheese at a slightly higher temperature than is common, and next, by ripening it in an apartment kept at from 65° to 67° F., and pro­nouncedly humid. On the other hand, ripening may be delayed by the adoption of a lower temperature, which both prevents the mould from growing so freely, and the bacteria (which play an important part in the conversion of the insoluble curd into soluble cheese) from carrying out their work so rapidly.

New makers are apt to take up a variety of cheese, the producers of which are already numerous. The Italians are producing more and more Gorgonzola, while in England, Stilton, being the most fashionable of the blue moulded cheeses of this country, has had the ranks of its makers reinforced so much of late, that the price has fallen to such an extent that the industry will presently not be worth following. There is great room for the extension of the system adopted in Wensleydale, and it is certain that if this cheese were systematically produced, and if it were mild and mellow as the very finest of the samples are, it would be much more largely sold than is possible under present conditions, under which its sale is almost localized, and its existence practically unknown in many parts of the country, to say nothing of the other English-speaking countries of the world. The manu­facture of all these varieties is taught at the British Dairy Institute, Reading, and we are in a position to know that the instruction is really worthy of the attention of those engaged in dairy work.