Arroyo R. Jambosa Malaccensis (Manzana Malaya) como Productora de Vinos y Brandies. Revista de agricultura de Puerto Rico, Volume 35 (1944), page 119-126
Jambosa Malaccensis (Malay Apple) as Producer of Wines and Brandies
By Rafael Arroyo, Ch. E. & S. E.
Fermentologo y Quimico consultivo Edificio Ochoa, San Juan, Puerto Rico
This fruit, better known as “Manzana Malaya”, “Pomarrosa Malaya”, and “Pomarrosa Americana”, has never been cultivated for commercial purposes, nor industrially exploited on our Island. Nor are we aware that industrial use and commercialization of this fruit has been made in other countries.
In a previous publication (1) jointly written by Mr. Julio S. Simmons, agronomist of the Experimental Station of the University of Puerto Rico, and the author, agricultural data and botanical description of the plant producing this fruit, were given to the public. In this publication the article that now concerns us was offered for later. It is the purpose of the present work to present the technical aspects in the industrialization of this fruit as the basis for the production of wines and brandies.
We believe that those of our readers who have not read the previous publication could better follow the course of the ideas presented here by taking the work of referring to that publication. And for those who do not have the time, interest, or desire to seek the publication we are referring to, we wish to inform you that a cuerda [0.97112 acres] of “Jambosa Malaccensis” can produce up to 10 tons of the fruit under commercial cultivation conditions, since in the form as it currently grows and develops it has come to produce the equivalent of five to seven and a half tons per cuerda. Let us now enter into the development of our theme:
COLLECTION AND TRANSPORTATION
OF THE FRUIT
This phase in the industrialization of this fruit is perhaps the only one that presents obstacles towards the establishment of a lucrative wine and brandy industry on our island, based mainly on “Jambosa Malaccensis” as raw material. The difficulty lies in the delicate and fragile nature of the peel of this fruit, and the great variety of microorganisms invariably present on them; especially over the peels of ripe fruits detached from trees and found in the soil beneath them. To avoid tearing the thin and delicate skin that covers the fruit, it is necessary to collect them with special care, ensuring that the fruits do not fall to the ground and handling them delicately so as not to injure their fine peels with finger nails. Those fruits found on the ground near or under the trees should be discarded altogether. Fruits taken directly from the trees should arrive at the winery at the most approximately in the same state in which they existed in the tree, and should be processed promptly, once they arrive at the winery. We can see in this way that in order to operate successfully, strict and frank cooperation between the activities of the field and the factory is extremely necessary.
As the harvest approaches, the winery laboratory must run a series of tests to determine the degree of ripeness of the fruits. These will consist of determinations of total sugars and acids; and through them it will be possible to collect the fruit in optimal conditions according to the kind of wine to be manufactured. The idea of harvesting fruits starting at a fixed time has to be discarded, since weather conditions will greatly influence the initiation and successive progress of fruit ripening.
As the fruits come off the tree very easily, collection can be made by hand during the morning, to be delivered to the winery later on the same day. The condition of the fruit would be much less satisfactory if it were collected during the afternoon, or throughout the day to make delivery on the subsequent day.
Fruits should be placed in small or medium sized baskets or boxes, thereby relieving as much as possible of the pressure exerted on the fruits at the bottom by those located above. These boxes must be kept very clean, and must be sterilized by direct steam at least twice a week. It would be an ideal condition that the winery be located adjacent or within the field where the fruit trees grow, since the hauling of the fruit over long distances must result in great deterioration of the same unless they are packed with extraordinary care. Also having the factory inside, or adjacent to the fields, the fruits can be collected during the early hours of the morning and delivered to the factory after noon. Finally, it goes without saying that when harvesting the fruits, they should be left without collecting all those past ripe, or that they have fungal growths on their peels; for sure, fruits in this state lower yields and harm the quality of the finished product.
PRIOR PREPARATION OF FRUITS
BEFORE DISMISSING OR PRESSING
The preparation of the fruits prior to their crushing or pressing will vary somewhat according to the type or class of wine that is to be produced from them, that is, according to whether red wine or white wine is the one required. Upon receiving, the fruits will be immersed in boiling water for a minute as a preventive against the possible effects of the abundant microbiological flora almost always present on their peel. Then those fruits from which white wine is to be made will be peeled; cut in halves and their seeds removed. The peels of these fruits are not discarded but stored in the most aseptic conditions possible, for use with that part of the fruits that are to produce red wine. Once treated, the fruits remain in conditions for the production of white wine.
If the production of red wine is desired, the fruits will not be peeled after immersion in boiling water, but will immediately go to the process of removing the seeds. Once the seeds are removed, the peels removed from the others used for white wine are incorporated into these fruits, and the mixture of fruits and peels is then shredded or pressed. The object is to obtain all the natural red color of the barks that are possible for the preparation of red wine.
CRUSHED OR PRESSED FROM FRUITS.
USE OF SULFUR DIOXIDE IN THE BATICIÓN
A special shredder was used during our experiments whereby the material could be obtained as a liquid with virtually no solid suspensions, or as a mixture of liquid and a very fine pulp in suspension, which included the excess peels used for red wine production. For the production of the highest quality white wine, only the liquid part extracted from the fruits was used; but when it came to red wine the solids from the pulp and the peels were mixed with the juice, as well as the surplus of peels from the preparation of the fruits for white wine.
At this stage of manufacturing the use of sulfur dioxide may or may not be used in the resulting batches. When it is decided to use the sulphurous treatment, it can be carried out in different ways: (a) in the form of sulphurous gas under pressure; (b) as a solution of sulfurous acid or (c) as a metabisulfite, preferably potassium metabisulfite. The advantages of sulfur dioxide treatment are based on its antiseptic action of selective effect; its reducing or antioxidant properties; and in its clarifying, solvent and acidifying influence. It is necessary, however, to exercise great care during this treatment, so that it does not interfere with the taste or maturation of the wine when subjected to excessive applications. This treatment can also result in cumbersome turbidity and sediment deposits in the wine.
If we have meticulously insisted on the description of how the fruit should be collected and transported, as well as the preparation that it should receive before being pressed or shredded, it is because it becomes possible to dispense with the sulphurous treatment, when the directions of collection, transportation and preparation indicated can be carried out strictly according to our recommendations. But as without a doubt, all the establishments will not be able to carry out all the requirements already mentioned in the handling and transportation of the fruit, we believe we are obliged to extend something more in the description of how to carry out this treatment of the baticións with sulfur dioxide.
It is very necessary and convenient in all cases not to overdo the use of sulfur gas; that minimum quantity calculated as sufficient for the subsequent fermentation control should be used at all times. According to Cruess (2) and referring to grape juice musts, one hundred parts per million sulfur dioxide will be sufficient to eliminate more than 99.9 percent of active cells of microorganisms found in the normal grape juice musts. This would be equivalent to 6 ounces of potassium metabisulfite per ton of juice.
Another very important precaution is to inoculate the batición after the effect of sulfur dioxide on the liquid that makes up the batición has almost completely passed, since otherwise and unless the yeasts were acclimatized to the treatment, they could be killed by the disinfectant action. Fortunately, yeast strains for wine can be easily trained to withstand the action of sulfurous acid. In spite of this, it is a good and prudent rule to wait until there is very little free sulfur dioxide in the mixture before proceeding with the inoculation of the yeast. The footing, or seed of yeast should be used at times of optimal fermentative vigor and with the highest cell concentration that may be possible to develop, since it is under these conditions that the antiseptic can best be resisted. The conditions of the fruit, its state of maturity and health, the temperature of the batición and other factors, will determine the intensity with which the sulphurous treatment should be applied. Very ripe fruits, of high saccharin richness, but of low acidity, will need a more intense treatment. As for diseased fruits, with fungi, or very deteriorated, we already said that they must be rejected altogether, but given the case that it is necessary to work with them, then their juices must receive a very extensive and intense treatment. When there is a means to effect subsequent fermentation at low temperatures, then the treatment with sulfurous acid can be lighter. This is due to the fact that at low fermentation temperatures, the bacteria in the mixture have less opportunity to develop and multiply. In the preparation of red wine it is necessary to be even more careful with the use of the sulphurous treatment, because if very intense, it can destroy the natural red color existing in the fruit peels. However, moderate and controlled use of sulfur dioxide will tend to intensify the red color due to its solvent action on the coloring matter of the peel.
According to research carried out by Bioletti and Cruess (3) certain advantages are achieved with the use of sulfur dioxide in fermentation work, among others the most prominent are: (a) More efficient fermentations both in terms of quantity and quality of the resulting wines; (b) great reduction in the amount of volatile acidity of the wines; (c) higher fixed acidity than in untreated wines; and (d) alcoholic yield can be increased by no less than one percent in wine.
In the case of “Jambosa Malaccensis” we have found, however, that when the precautions and directions given in previous paragraphs are rigorously carried out, then the sulphurous treatment of the batición can be dispensed with, especially when a pure yeast culture is available and of fast fermentative power. The use of this pure culture of yeast is almost imperative, because the treatment with boiling water to which the fruits are subjected practically destroys those adventitious yeasts that almost always accompany them (the fruits) at the same time as other undesirable microorganisms that they swarm over their peels.
FERMENTATIVE TECHNIQUE FOR THE
RED WINE PRODUCTION
We have already indicated previously that for the manufacture of red wine the combined mass of: (a) fruit liquid, (b) pulp and shredded peels is used, (c) the surplus of shredded peels from those fruits used for production of white wines. We must before going ahead with the description of the fermentative method, to state that although we speak of red wine produced from the “Jambosa Malaccensis” this fruit lacks sufficient amount of natural red pigment to produce red wine of intense color. Actually, what it produces is rosé wine, the artificial coloring of the wines being necessary when a wine of intense red color is desired. This constitutes another disadvantage of the fruit for the manufacture of red wine. We must not forget, however, that there are artificial colors that can be legally used in the production of wines, which are in great use and demand by wine manufacturers in both Puerto Rico and the United States.
Returning to the description of the fermentative process for the production of red wines, we have that the above-described batición will have a total sugar concentration equivalent to 6 to 8 grams per 100 milliliters of batición. This total sugar content would be too low to obtain the necessary percentage of alcohol in the already fermented batición, and therefore it is necessary to add cane sugar until obtaining between 24 and 25 grams of total sugars per 100 milliliters of batición. With this concentration of total sugars, and good fermentation, wines from 13.0 to 14.0 percent alcohol by volume can be obtained. The acidity of the batición will also need to be adjusted in some cases. This is a matter of great importance since the acidic content of the mixture not only influences the development of fermentation, but also the formation of taste in the wine and its preservation. When we achieve optimum acidity, the formation of taste in the wine reaches higher levels, the growth of bacteria and other contamination becomes more difficult, and the resulting wine is much more resistant to the attack of deleterious microorganisms during the aging stage.
In the course of our studies with “Jambosa Malaccensis” we have found that if the fruit was used in the most propitious stage of its maturity, and especially in the case of using the fruit for the manufacture of red wine, the degree of acidity obtained usually in the batición it is appropriate, and readjustments become unnecessary. There are, however, occasions when this adjustment of acidity is necessary, especially when very ripe fruit is used. In these cases the acidity must be balanced by applications of tartaric acid in such quantities that the final acidity expressed in terms of tartaric acid is 0.8 grams per 100 milliliters of batición. The natural acidity of the mixture in the case of red wine is almost always between 0.6-1.0 grams of tartaric acid per 100 milliliters, so it is very rare that the incorporation of more acid is necessary. As for tannin, its addition would be superfluous since in the peels of “Jambosa Malaccensis” this substance is found in adequate amounts. We found, however, that fruits frequently suffered from deficiency in nitrogen and phosphoric acid, which is why we needed to add small amounts of ammonia tartrate and potassium phosphate to the baticións. It never became necessary to add more than 2.25 grams of ammonia tartrate and 0.45 grams of potassium phosphate per gallon of batición. This corresponds to 5 pounds and one pound, respectively, of tartrate and phosphate per 1,000 gallons of batición.
Having thus treated and conditioned the batición is ready to be fermented. In our experiments only pure yeast cultures for wines were used as fermentation initiators. Much of the success in wine fermentation lies in the use of a pure yeast seeding, in the right concentration and in perfect state of health and vigor. Therefore, we can never be too careful in the preparation and propagation of the pure yeast footing that has to start our fermentations. In our case we always began the preparation of the footing or seeding of a solid culture of the yeast in question, which was only used for a couple of months. After this time the solid crop was replaced by a recently made one. Using this precaution we were always sure of the fermentative vigor and general health of our initial source of yeast.
Previous experiments carried out on a small scale had shown that for the manufacture of red wine using this fruit as the first material, a strain of “Bordeaux” yeast brought from Europe by the author of this article, proved to be the most efficient and imparted the best taste to the wine. The technique followed in the use of this yeast to make the footing or yeast seed was the following:
From the solid culture a platinum thread was used to remove a leep full of yeasts, with which a test tube containing about 25 milliliters of a sterile mixture was inoculated of Malay Apple juice. This tube was kept in an incubator at a temperature of 27 to 28 degrees Celsius until vigorous fermentation started, which usually took 18 to 24 hours. With the liquid in active fermentation the test tube was then used as inoculum of another 350 milliliter beaker contained in a 500-milliliter “Erlenmayer” flask. The “Erlenmayer” flask liquid served as the inoculum of a glass vessel containing 2 gallons of Malay Apple juice, which in turn finally served as inoculum to a fermenter containing 150 liters of fresh batición of the fruit in question.
Knowing that temperature control is one of the most essential and important points in wine fermentation, our experimental fermenter was located in a room equipped with air conditioning and whose temperature was adjustable with certainty between 18 and 28 degrees Centigrade scale. This fermenter also had a cooling coil made of stainless steel and electric heating. This fermenter could be worked as a closed or open unit, according to the manufacture of the kind of wine that occupied it at the moment. When it was desired to ferment to obtain red wines, the fermenter operated as an open unit. During the fermentation, a temperature varying between 27 and 28 degrees Celsius was maintained in the fermentation tank contents. Precautions were taken for the management of the solid mass that in the form of a hat or bonnet appears on the surface of the batición. This cap composed of the solid materials of the mixture that are brought to the surface by the carbonic gas that develops in the liquid under fermentation, must be pushed down inside the liquid at regular intervals during the period of fermentation. This control of the cap or bonnet during the fermentation of red wine is an intricate and extremely important issue, when it comes to the manufacture of wine on a commercial scale, as we will explain in due course. Once the fermentation started, in our case, it took between 96 and 108 hours.
From an industrial point of view, the equipment used must be resistant to corrosion, and must not impart strange and undesirable flavors or odors to the wine. Avoid as much as possible any metallic contact with the wine during or after its preparation. In the case of small establishments the indicated solution is to use all the wooden equipment that is possible. For large-scale installations, the use of stainless metals or alloys, or glazed equipment, is possible with a large turnover; but only through considerable expense. Because “Jambosa Malaccensis” grows only in a very small amount at present, the first possible operators of this raw material will be forced to operate on a small scale for several years. Therefore we believe that potential industrialists will be more interested in the type of small vessel using predominantly wooden equipment. We wish to state as a matter of information, that according to Mrak and associates (4) metals of modest resistance to the action of batición prove satisfactory as long as the contact time is not prolong too much.
Returning to the wooden equipment, we hold that white oak or redwood (redwood) should be preferred for the construction of fermenters. These fermentation tanks should be small to medium sized, and in no case would they be desirable with a capacity greater than 3,000 gallons. The disadvantages of very large tanks are that it is difficult to control the quality of the raw material used, as well as the temperature and speed of the fermentation. On the other hand they are also more difficult to handle for cleaning, sterilization, arrangements, etc., etc. Small or medium sized tanks last in good condition for many years, and support artificial cooling much more easily and efficiently. In addition, its ability to radiate heat into the atmosphere is also superior to that of large tanks.
To obtain success in the manufacture of wines in tropical countries, we believe it is necessary to attend preferably to the temperature control factor. Even in the case of small fermenters (between 500 and 1,000 gallons) the temperature frequently rises to dangerous heights with possible deterioration in quality and performance in the wine. The lower the temperature, within the appropriate limits and accepted in good practice, the higher the alcohol concentration that can develop in the environment; and we have that this development of high alcohol concentrations in wine is a matter of extreme importance, especially in warm countries where deterioration of those wines with low alcohol concentration is very feasible, during the maturation period or after bottling. This fact is recognized by European wine exporters who, when sending their wines to warm countries, export those with high natural alcohol content, or fortify those brands that are currently sold with low alcohol content in European countries with grape or potato alcohol. In Puerto Rico, for example, the fortification of poor wines in natural alcoholic content would have to be made with honey alcohol often defective in quality; and that they always impart unpleasant taste and smell to wines fortified with them. Therefore, our wine producers must pay particular attention to fermentation so that it is possible to obtain the highest possible wealth in the alcoholic concentration. [Mieles translated to honey, but I am not certain he means bee honey and not a cane product.]
The damages and dangers of high temperatures during the fermentation period are many. We explain below the best known:
(1) It becomes very difficult if not impossible to develop the desired alcohol concentration in the wine. For example, our experience as a technical consultant has shown us that usually only an alcohol concentration is reached between 7 and 9 percent in fermentation under tropical conditions unless artificial refrigeration is used. Trying to obtain high percentages of alcohol in the wine during fermentation using the expediente to raise the sugar content in the batición, only results in wasting of sugars, since the yeast will stop its fermentation activities as soon as it is inhibited by the complex of Alcohol and high temperature. In the Müller-Thurgau experiments (5) portions of the same mixture were fermented at different temperatures, obtaining the following results:
These results immediately demonstrate the disastrous effect of high temperatures on the possible alcohol yield. These results also explain the difficulty in producing dry table wines in tropical countries.
(2) When wine is fermented at high temperatures, in addition to the difficulties outlined above, we have another form of alcohol loss. It consists in the loss by evaporation or by entrainment under the action of the carbonic gas that escapes the batición. The author of this article conducted demonstrative experiments on evaporation and entrainment alcohol losses, finding that under conditions prevailing in Puerto Rico, 7.5 to 10.0% of all alcohol formed during the fermentation period could be lost.
(3) Another setback caused by high fermentation temperatures is the fact that disease-producing bacteria in wine are highly favored in their multiplication and development.
(4) Autolysis and endoproteolysis of yeast cells are also caused by high fermentation temperatures. This not only reduces alcoholic yields, but can also give birth to bad taste and smell in wine; while increasing the chances of the rapid spread of a bacterial infection already present, because the products of autolysis and proteolysis of yeast cells are excellent foods for bacteria.
If we let such conditions develop in the winery, we will find “suspended fermentations”, a phenomenon known in the English language for “stuck wine”. This phenomenon occurs in a wine when fermentation ceases, while there is still a significant amount of sugar available for conversion to alcohol in the liquid. These wines are usually damaged or deteriorated rapidly in the maturation room due to the development of harmful bacteria in their womb.
The phenomenon of “suspended fermentation” in winemaking can be attributed to one of the following causes or combinations between them:
(a) Very high temperature.
(b) Presence of too much sugar in the batición.
(c) Batición infected with deteriorating bacteria.
Being a phenomenon of frequent occurrence in our country we believe it is pertinent to offer standards for its treatment: When the fermentative suspension is due to a very high concentration of total sugars in the medium, it is easily solved by diluting the mixture with the purest water possible and aerating it immediately, moderately. In this aeration the use of sterile air is preferable. If the cause is due to very high fermentation temperature, the remedy is to cool the liquid with the greatest haste. The quickest method to carry out this cooling is to add ice in small pieces inside the batición and stirring the fermenter contents with a mechanical stirrer or by hand. When acetification of the liquid due to bacterial infections is the cause, then a serious and difficult problem arises. The best course to follow in this case is the destruction of the bacterial infection by means of heat, followed by rapid cooling of the liquid and reinocculation with a new yeast footing in a vigorous fermentative state. Another solution is to distribute the content of the damaged fermenter after heating and cooling among other fermenters that are in full and vigorous fermentation. We must warn that for any of the remedies offered here to have a positive effect, it is necessary to act immediately that the effect of “suspended fermentation” is noted, because if appreciable time is allowed to pass, a day or more without addressing the matter, then it would be It is very difficult to be successful with the treatment, but in any case it is much more convenient to prevent “suspended fermentation” than to try to remedy it once it has occurred.
Another point of great care in the preparation of “Jambosa Malaccensis” red wine is the issue of the cap or bonnet which, as we explained above, is formed on the surface of the liquid under fermentation. A defective or careless handling of this cap or bonnet can bring the improper extraction of color, flavor and tannin from the fruit peels, and it can also be the cause of deterioration in the wine. This bonnet should never remain for more than four to six hours without being pushed down in the batición liquid under fermentation. Otherwise there must be a pump that, by removing liquid from the lower part of the fermenter, pumps it over the surface of the cap or bonnet. The more dry and hot the environment is, the more necessary this humidification of the bonnet becomes, because otherwise, the acetification process would start quickly with this cap, then spread to the fermentation liquid. We must also always keep in mind that all the natural color of the wine is extracted from the peels that form this bonnet, and that if it is not beaten into the liquid, or liquid is constantly pumped through it, we will have a great color deficiency in the wine. We have already explained that this color deficiency always exists in the case of red wine prepared from the Malay Apple, a deficiency that has to be repaired through the addition of artificial coloring. However, in the manufacture of the so-called “rosé wine” that classifies within red wines, the use of artificial coloring becomes unnecessary if the bonnet is known to work as we have already indicated.
The danger of damaging the wine due to defective or poorly careful control of the bonnet is much greater in Malay Apple wine than in wine made from red grapes. This is because the grapes have much more red pigment in their skins, and therefore require much less time to contact the liquid to impart the desired color; while in the case of the Malay Apple it is necessary to maintain the contact of peels and liquid practically during the entire duration of the primary fermentation. This greatly increases the opportunity to damage the wine by acetification. In the case of grapes, the liquid is separated from the cap or bonnet as soon as it (the liquid) has acquired the desired color intensity.
Once the primary fermentation is finished, which can take between 5 and 7 days, the liquid is extracted from the bottom of the fermenter or preferably from a perforation two or three inches from the bottom. The component material of the cap and a small part of the liquid is at the bottom of the fermenter from which it is extracted and subjected to the action of a hydraulic press to extract the liquid in it. This press wine should not be mixed with the one previously extracted from the fermenter because it is of a lower class.
The wine first extracted freely from the fermenter is passed through an ordinary filter with the purpose of separating that thick matter that, it may bring in suspension, and is then subjected to a secondary fermentation at a temperature between 21 and 23 degrees Celsius. In order to carry out this second fermentation in the tropics it is necessary to use artificial cooling.
The second part of this article will appear in an upcoming issue of this Magazine.
Bioletti, F. T. y Cruess W. V. “Enological Investigations” Calif. Agr. Exp. Sta. Bul, 230:1-118; 1912.
Cruess, W. V.—”The effect of sulphurous acid on fermentation organisms.” Journal of Industrial and Engineering Chemistry, 2:581-85; 1912.
Experimentos de Müller-Thurgau citados por Antonio F. Sannino—Tratado de Enología. Gustavo Gili, Barcelona, España.
La Manzana Malaya (Jambosa Malaccensis). Julio S. Simmons y Rafael Arroyo. Rev. Agri. y Com. de Puerto Rico. Volumen 29, marzo 1942.
Mrak, E. M. & L. Cash & D. C. Caudron.—”Effects of certain metals and alloys on claret and sauterne types of wines from vinifera grapes. Food Research 2 (6):539-47. 1937.