TY - JOUR T1 - Yeasts of Wine Fermentations from Various Regions of Italy JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 18 LP - 19 DO - 10.5344/ajev.1955.6.1.18 VL - 6 IS - 1 AU - Tommasso Castelli Y1 - 1955/01/01 UR - http://www.ajevonline.org/content/6/1/18.abstract N2 - This paper considers the identity and fermentative capacity of yeasts found on Italian grapes and musts. The biological side of fermentation in wine making has been touched on in this way in Italy in several important studies by Ravizza, Peglion, Pichi, and Marescalche, Mensio and others. There is much need for additional systematic work on this point.The work done at the Institute of Technical and Agricultural Microbiology, University of Perugia, since the early study of de Rossi, about 1920 (1), is reviewed. De Rossi reported on the apiculate, yeast cells, Pulselli (2) studied the yeasts of musts and de Rossi (3) further investigated the yeasts of vinification, in the region of Umbria. In the latter study, 87 samples of must, crushed within 24 hours, were received at the laboratory from all parts of the region. They were subjected to study immediately on arrival. The work included incubation for 6 to 8 days at 16 to 18°C (about 60 to 65°F), microscopic examination of the fermenting musts, and isolation and identification of pure yeast cultures. This program permitted microbiological developments to be followed during fermentation.Identification procedures followed the modern work of Stelling-Dekker (4), Lodder (5) and Diddens and Lodder (6). The predominant species of yeast in each fermentation was isolated, and the alcohol production of each isolated species was determined in sterile must enriched with sugar. This work produced 379 pure cultures of yeasts. Castelli, in 1936, worked on musts from the region of Chianti and the foothills of Siena and Florence (7). Ninety-three musts yielded 375 cultures. In 1937, Castelli obtained 63 cultures from 10 musts of Chianti (8). In 1939, Santarelli (9) isolated 192 yeast cultures from 22 samples from the Roman Castle region, and in 1941 Sensi (10) isolated yeasts from samples from Orvieto and Viterbo. Castelli, in 1946, isolated 203 yeast cultures from 20 samples from the flatlands of Ascoli Piceno and the foothills up to 500 meters (11). Castelli (12) and Caramazza (13) isolated 60 and 25 yeast cultures from Sicilian musts, in 1947. Later in that year Castelli obtained 363 yeast cultures (14) from the southern (Manduria-Squinzano), the central (Barletta-Corato) and northern (San Severio-Lucera) regions of Puglie at 400 meters elevation, the latter known for a premium white wine.The results of work on yeast cultures obtained from musts from central Italy are shown in a table. The names of the species of yeasts isolated are listed, together with the relative number found in the musts, the percentage frequency of occurrence and minimum and maximum percent alcohol by volume produced in must. The tabulated data show that 25 species of yeasts were found, with Kloeckera apiculata (Pseudosaccharomyces) and Saccharomyces cerevissiae var. ellipsoideus (Sacch, ellips.) vastly predominating in the must. A brief summary of the table indicates that the following yeasts cannot be excluded from consideration in the normal and regular processes of vinous fermentation in central Italy.Number of must samples, 242. Number of cultures isolated 1,301.See PDF for TableThe findings for the Puglie district where 27 species of yeast were found, did not conform in detail to those for central Italy. The results for Puglie show that the apiculate species. Haneniaspora displaces Torulaspora in third place. Also, another species of Kloeckera (K. africana), earlier found only in the soil of Algiers, appeared in Puglie. More apiculate and spore-forming yeasts were found in Puglie. Puglie musts contain greater percentages of desirable yeast species, and the individual Puglie species had greater capacity for alcohol production, than in central Italy. An additional point concerned the manner in which grapes were delivered to the laboratory. In Northern Puglie the grapes were delivered in baskets. In Southern Puglie they came crushed in barrels, carried by horses or mules over distances as great as 40 kilometers, and arrived in an advanced stage of fermentation. (Editor's note: on this point compare with Cruess (18)). The maximum alcohol production data was summarized as follows: yeasts of Umbria, 17.17%; of Tuscany, 17.61%: of Lazio, flatland 15.6%, foothills 17.9%; of Publie, 18.55%.Castelli put forth several practical ideas derived from the above studies. It should be possible, with so many strains of yeast from a variety of regions of Italy, to produce any desired type of wine by careful selection of yeast culture and regulation of fermentation conditions. This idea was based on fermentation experiments with yeasts from the musts of Central Italy (15, 16). The yeast species Torulaspora rosei was suggested for vinification of musts low both in sugar and acid, which are common in Italy (17). Torulaspora has been used on a commercial scale for the production of vin rosé and normal red wines. Good dry wines were obtained with volatile acids of between 0.028 and 0.033 for vins rosé and between 0.04 and 0.05 for wines fermented on the skins. Yeasts obtained from one part of Italy have been used successfully in wine making in another part of the country. In commercial use are a number of yeast strains which ferment actively, but little is known of their origin and enological characteristics. (Editor's note: on this point, compare with Castor (19)). The determining factor in employing a strain of yeast should be that it has been carefully selected from a number of cultures of known characteristics. ER -