The Manufacture of Butter and Cheese with Culture Starters

in Italy

by

Prof. COSTANTINO GORINI,

of the Royal Higher School of Agriculture of Milan.

The use of culture starters in the preparation of butter and cheese in Italy dates respectively from the years 1895 and 1903.

Butter. In the summer of 1895 the late Prof. Giuseppe Sartori and I, were at Copenhagen, encouraged by the Minister of Agriculture, to study the Danish method of butter making with selected starters, This method, as is well known, consists in pasteurizing the cream with the object of killing or paralyzing the natural germs, which may be good or bad, and then adding a pure culture of certain determined ferments, which were shown in 1890 by Prof. Vincent Storch of the Agricultural Station of Copenhagen to be the specific agents in the ripening of cream.

In this manner the factors of chance and empirism were eliminated from the process of the souring of cream, which with the old methods used to take place naturally during the rising of the cream according to our methods, or was artificially brought about in centrifugated cream by the addition of sour buttermilk or of some other empirical starter, as was customary in the North of Europe.

On our return to Italy we hastened to divulge the salutary reform. I, who was chiefly interested from the scientific point of view, emphasized the hygienic and bacteriological significance of the process, in lectures held at the Agricultural Association of Lombardy, at the Athenaeum of Brescia, and at the Royal Italian Society of Hygiene. Sartori, who studied the question in its technical aspect, actively set to work to describe the practical execution of the new method in reports to the Ministry, to experiment it in the dairy of the Royal Agricultural School of Brescia, and to teach it and to spread it amongst producers by means of lectures, and verbal and printed instructions. And already in 1897 he was able to announce that the reform had been definitively adopted by several dairies (1).

The Ministry of Agriculture began to favour the propaganda with subsidies and by means of special competitions for butter prepared with culture starters (Lodi 1898, Milan 1906, Turin 1911).

(1) See Bollettino Ufficlate del Ministero di Agricoltura, Rome 1897.

(Author's note).

The first to adopt the new process were the great dairies of the district of Milan among which the firms Antonio Zazzera of Codogno, Polenghi Lombardo of Lodi and Codogno and Locate Triulzi near Milan occupy mcst honourable positions. The example of these was soon followed by other firms, especially of Lower Lombardy (Mangiarotti of Lomello, Gallone of Milan, Gianelli Majno of Mortara, etc). In fact this region produces more butter than any other milk-producing district of Northern Italy; it is here that, owing to the distribution of landed property and to the favourable topographical conditions it is possible to collect the large quantities of milk necessary to the creation of great industrial establishments like those of San Fiorano, Somaglia, Acquanegra, Olmeneta, Secugnago, Sant'Ar gelo Lodigiano, Melegnano, Casalpusterlengo, Offanengo, Rogoredo, Abbiategrasso, Borgosa tollo, Soresina, Casalbuttano, etc. All these are localities in which important dairies were founded either ir dependently or as branch houses of other firms, and in all of which the Danish method of buttermaking was adopted.

At the same time other regions of Italy, such as Piedmont, Emilia, Venetia, Friuli, Liguria are not without examples of large dairies in which selected butter starters are used, if not continuously at least intertermittently when required and according to demard; their number is always increasing. Quite recently a large Piedmontese dairy, Barberi of Moretta, has, with my assistance, adopted culture starters.

It is not an easy task to ascertain the quantity of butter made at present on the Danish system in Italy, as industrial firms do not like to give publicity to their affairs, partly through fear of heavier taxation. It may, however, be approximately deduced from the statistics of exports, admitting that the butter exported, about 78 700 cwt. per annum, is all made with culture starters. It is, however, to be noted that a portion of the butter exported, especially that for the French Riviera, is still prepared from cream allowed to rise and ripen naturally, while on the other hand butter made on the Danish system is demanded also by the home trade, thus proving the increasing recognition of the advantages offered by the new method.

As is well known, these advantages may be summarized as follows: more delicate aroma, greater constancy of type and improved keeping qualities. Of these the most generally recognised are the two latter and especcially the last, namely the greater resistance to turning rancid.. Upon this resistance the greatest stress is laid in judging butters in shows and competitions. As for the aroma, the same observation has been made in Italy as abroad, especially in France. There are some farms in which the butter made in the old way turns out more sweetly scented than by the Danish method. Whether this depends upon special natural aromas or on special breeds of aroma-producing bacteria, both of which are destroyed by pasteurizing the cream and cannot be developed or replaced by the selected starters now in use, is a question requiring further study. Moreover it must not be forgotten that the development of the taste in butter made on the Danish lines is always slower than in butters made

in the old way, and that on the other hand the unsatisfactory results of the Danish method are frequently due to the negligent and imperfect way of applying it. Some dairies which had abandoned it have returned to it after having introduced some opportune modification either in the pasteurizing process, or in the multiplication and choice of the ferments, or in the inoculation, incubation and acidification of the cream. As for the original cultures used in Italy. they come almost exclusively from abroad. Among the firms patronized, Blauenfeldt and Tvede of Copenhagen, Hansen also of Copenhagen and H. Berend and Co. of Wildeshausen deserve to be mentioned. Regarding the multiplication of the ferments and the ripening of the cream, it is not easy to know the methods adopted by the different dairies, as these like to keep to themselves their technical details which often contain the secret of their success. Besides, it is obvious that exactly the same rules cannot be followed in all cases, especially as the demands of the customers in the matter of flavour and degree of acidity of the butter have to be complied with.

But if there may still exist some uncertainty and some exceptions concerning the delicacy and pleasantness of the taste, in the matter of amount, purity and constancy of the flavour the superiority of butter made on the Danish system is being always more firmly established; this is demonstrated by the facts that the home consumption of butter made with culture starters is on the increase, and that the system is being utilized for the improvement of butters destitute of taste, as is the case sometimes in winter, or of second rate butters such as whey butter, especially when this is a by-product of the making of cheese resembling ewes' milk cheese. In this case the cream acquires an unpleasant taste and odour which can be attenuated, if not removed altogether only by pasteurization and by the addition of a good culture starter. In other words the use of culture starters is constantly gaining favour as a means of improving naturally inferior butters and raising them to the level of good butters.

Cheese. In 1903, under the presidency of Senator Giulio Vigoni, an Association among cheese producers and traders was formed in Milan with the object of experimenting practically the methods proposed by me for the improved manufacture of cheese.

This method is based upon the same principles as those upon which the Danish method of butter making is founded; that is, using a milk which is bacteriologically pure and to which pure cultures of good cheese ferments have been added. Here, however, the task is more difficult for the two following reasons: in the first place for the purification of the milk, pasteurization cannot be relied upon in an absolute manner, it having been shown that the temperature to which milk must be raised so as to kill all the germs it may contain is injurious to its properties for cheese making: secondly, because while the ripening of cream, which is after all only a mere acidification, is very simple, the ripening of cheese is a very complex process of which we are still far from knowing all the factors and all the biochemical products.

Nevertheless my scientific and practival investigations had put me in possession of facts that seemed to me to be of immediate practical application for the improvement of the manufacture of at least the hard or cooked curd cheeses, the making of which as well as the micro-flora which accompanies their ripening being much simpler than in the case of soft cheeses. These facts may be summarized as follows:

1) By means of opportune hygienic measures which can be carried out in practice, it is possible, without having recourse to pasteurization, to obtain a milk relatively free from bacteria, and sufficiently so to allow of the useful addition of selected ferments. These measures must be taken ab ovo, that is by preventing the contamination of the milk (devoting attention to the feeding, to the cleanliness of the cows and especially of their udders, to clean milking etc), and they must be completed by preventing the multiplication of the bacteria in the milk (cooling and protecting the milk up to the moment of working it up).

2). The present knowledge on the ripening agents of cooked-curd cheeses is sufficient to allow of the substitution of the empirical ferments now used in cheese making (fermented whey, fermented milk, etc.) by pure cultures of certain ferments. Provided that in the choice of ferments the following scientific and practical facts relative to the making and ripening of hard cheeses be borne in mind: a) that in these cheeses a rapid lactic fermentation takes place without production of gas and accompanied by proteolytic processes. b) that their cooking temperature attains 50° C (1220 F) and upwards. Consequently the bacteria to be chosen must be taken from good cheeses, and must possess the following general physiological requisites: they must be lactic ferments not producing gas, energetic, proteolytic and resistant to heat.

3. The use of selected ferments requires processes favourable to them. With this object it is necessary: a) to consider the most favourable conditions of temperature, moisture, etc., for their development and action; b) to exclude every kind of empirical starter and of impure rennet that may neutralise the action of the culture starters; c) to abstain from all those expedients, such as the use of too high temperatures, of an excessive degree of acidity and of antiseptics which tend to control harmful germs but at the same time prove injurious to the useful ones.

Working on the above lines, the Association began in 1903 at the Trenno cheese factory near Milan to use culture starters in the preparation of the classical Italian cheese, Parmesan or Grana. From the very

beginning success attended the new deparcture, so that already in 1906 at the Milan International Exhibition three year-old ripe experimental cheeses could be presented together with the control cheeses, and they obtained completely favourable judgment from two international juries. The authoritative "Milchzeitung" of Leipzig (1) said that it was the first time that a Commission of international experts could verify the results

(1) Year 1907, No. 9.

obtained, with rigorously experimental methods, by selected ferments, and convince itself of the possibility of exerting a favourable action on the quality of the cheeses made by introducing culture starters into practical use. Encuraged by the good results obtained with Parmesan of the Lombard type (Lodigiano) and of the Emilian type (Reggiano), the Association turned its attention to other types of hard cheeses, such as those of the Valtellina (Bitto), of the Bergamo district (Branzi), of the Friuli (Montasio), the cacio cavallo, the Swiss cheeses (Fribourg and Emmental) and margarine cheeses, and with all of them obtained further confirmation of the value of the method.

All who have tried and adopted it bear witness to the following advantages: 1) considerable reduction in the number of defective cheeses; 2) greater uniformity of characters; 3) improvement in the most esteemed qualities (eyes, softness, flavour); 4) improved keeping quality.

In 1905 the Association resolved to found a cooperative bacteriological laboratory, under my direction, for the preparation of selected ferments, in order to supply them to both members and non-members at cost price and in the case of scientific institutions, travelling lectureships of agriculture, etc., at reduced prices and even gratis.

By means of lectures, communications to national and international congresses, of exhibits at shows and competitions, and of advice given personally, or by printed leaflets, the modern principles of cheese-making founded on bacteriology and on hygiene were spread throughout the country. The results of researches and of experiments embodied in yearly reports are published in the Official Bulletin (1904 and following years) of the Ministry of Agriculture (which grants a subsidy to the Association). So that now it may be said that the knowledge concerning culture starters and their use has become public property.

In the last seven years (1906-1912) 56 629 doses of culture starters, each sufficient for 110 gallons of milk, were distributed. The figures for the several years are as follows: 1906, 2276; 1907, 6449; 1908,6261; 1909, 6564; 1910, 12114; 1911, 11609; 1912, 11356. The decrease of the two years 1911-12 is due partly to the smaller quantity of milk treated by several consumers ou acconnt either of the rise in the price of milk or of the foot-and mouth disease, and partly to the fact that some of the usual consumers suspended the manufacture of cheese in favour of the preparation of condensed and sterilized milk. Among the constant consumers of culture starters several of the best and most conscientions cheese makers and the principal industrial dairies are to be found (1).

Whilst at the Milan International Exhibition of 1906 the only cheeses made with culture starters were those of the above mentioned Association, at the Jubilee Exhibition at Turin in 1911 several cheeses made with culture

(1) GORINI. Rendiconti del Reale Istituto Lombardo di Scienze e Lettere. Milano, 1912, p. 863.