University of California

The relation of maturity of the grapes to the yield, composition, and quality of raisins


H. E. Jacob

Author Affiliations

H. E. Jacob was Associate in Viticulture and Associate in the Experiment Station.

Publication Information

Hilgardia 14(6):321-345. DOI:10.3733/hilg.v14n06p321. February 1942.

PDF of full article, Cite this article


Abstract does not appear. First page follows.

That the maturity of grapes is related to the yield and quality of the raisins made from them has probably been observed almost as long as grapes have been dried to preserve them. Apparently, however, no one attempted to determine precisely the nature and magnitude of these relationships before the work done by (Bioletti (1915)),3 which was begun about 1913. Important contributions have since been made by (Lyon (1920), (1924), (Cruess and Christie (1921)), and (Nichols and Christie (1930)).

(Bioletti (1915)) reports on tests made with Muscat of Alexandria and Sultanina (Thompson Seedless) at Kearney Park, near Fresno, and at Davis, during the seasons of 1913 and 1914. With Muscat, the drying ratios reported ranged from 4.8 for grapes of 18° Balling to 3.1 for grapes of 28° Balling. Quality, as measured by the size of the individual raisins, improved notably as maturity advanced. With Sultanina, the drying ratios ranged from 4.6 for grapes of 20° Balling to 3.6 for grapes of 24° Balling. According to Bioletti’s calculations, the average increase in crop per Balling’ degree of sugar in the grapes was about 5.35 per cent with Muscat and 7.4 per cent with Sultanina. In another paper (Bioletti (1919)) briefly reported, collectively, on the results of several years’ tests on the drying of eleven varieties of grapes. He interpreted his results as showing an average increase of 35 pounds of dried grapes per ton of fresh for each added degree of sugar. Actually, his figures show the increase to range from 16 to 104 pounds, the greater increases being obtained from the riper fruit.

Literature Cited

Association of Official Agricultural Chemists. Official and tentative methods of analysis. 1935. Washington, D. C.: Published by the Association. 710p.

Bioletti Frederic T. Relation of the maturity of the grapes to the quantity and quality of the raisins. 1915. California: International Congress of Viticulture, Panama Pacific International Exposition, San Francisco. p. 307-14. Official Rept.

Bioletti Frederic T. Dried wine grapes: Methods and returns. State Board of Viticultural Commissioners, Sacramento, California. Bul. 1919. 15:6-9.

Chace E. M., Church C. G. Tests of methods for the commercial standardization of raisins. U. S. Dept. Agr. Tech. Bul. 1927. 1:1-23.

Christie A. W., Barnard L. C. The principles and practice of sun-drying fruit. California Agr. Exp. Sta. Bul. 1925. 388:1-60. http://archive.org/details/principlespracti388chri

Cruess W. V., Christie A. W. Dehydration of fruits. California Agr. Exp. Sta. Bul. 1921. 330:53-54. http://archive.org/details/dehydrationoffru330crue

Castella F. de. Sultana drying by the cold-dip process. Victoria (Australia) Dept. Agr. Jour. 1925. 23(12):716-31.

Lyon A. V. Mildura Research Committee experiments with the drying of vine fruits. Sci. and Indus. (Australia). 1920. 2:625-29.

Lyon A. V. Problems of the viticultural industry. Australian Inst. Sci. and Ind. Bul. 1924. 28:1-84.

Lyon A. V. The mixed dip for Sultanas. Australian Dried Fruit News. 1934. 9(2):1 11. March 7, 1934.

Nichols P. F., Christie A. W. Dehydration of grapes. California Agr. Exp. Sta. Bul. 1930. 500:1-31. http://archive.org/details/dehydrationofgra500nich

Shaeffer P. A., Hartman A. F. The iodometric determination and its use in sugar analysis. Jour. Biol. Chem. 1920. 45:349-90.

Student. The probable error of a mean. Biometrika. 1908. 6:1-25.

Student. Tables for estimating the probability that the mean of a unique sample of observations lies between -? and any given distance of the mean of the population from which the sample is drawn. Biometrika. 1917. 11:414-17.

Yoe John H. Photometric chemical analysis. Colorimetry. 1928. 1: New York, N. Y.: John Wiley and Sons, Inc. 771p.

Jacob H. 1942. The relation of maturity of the grapes to the yield, composition, and quality of raisins. Hilgardia 14(6):321-345. DOI:10.3733/hilg.v14n06p321
Webmaster Email: wsuckow@ucanr.edu