1028 EXPERIMENT STATION RECORD. 



Notes on vinegar making, E. F. Perxot {Oregon Sta. Bui. 73, x>p- 8). — Yine^ar 

 ■was nuide at the statimi from undersized and otherwise unsalable prunes. After 

 running the washed and weighed prunes through a homemade machine with spiked 

 rollers which lacerated and tore them, the mass was inoculated with a pure culture 

 of yeast {SaccJuironvjces cerensia). This caused a strong and rapid fermentation, 

 ■which broke do-wn the cell walls of the prunes, thus liberating the clear juice, which 

 flowed into a receptacle below the vat. This method of securing the clear liquid was 

 inexpensive and very satisfactory. In all 10,482 lbs. of Italian prunes were used, from 

 which 6.30 gal. of juice was obtained, or a yield of a little more than 3 gal. of juice 

 per bushel of fruit. The juice was fermented in open liarrels. Fermentation was 

 completed in 10 days, when the juice was found to contain 10 per cent alcohol. It 

 ■was then inoculated with a pure culture of vinegar ferment [BaclUi jxiKtrnramun) by 

 floating it on the surface of the liquid by means of pieces of cork weighted so as to 

 bring the culture in contact with the liquid. 



The vinegar thus produced was of excellent quality, with a fruity flavor and good 

 body, analyzing 6.89 i>er cent total solids. The only objection to it was its color, 

 which was that of very dark wine. It was, however, but little darker than imported 

 malt vinegars, which find ready sale in Oregon markets. Experiments are now in 

 progress to see if some method of clarification can l)e found which will inqirove the 

 color. The machine used for lacerating the jirunes and the vat for fermenting ar.d 

 collecting the juice are described in detail, and a ])rief discussion given of the prin- 

 cijjles of vinegar making and of the best ways of making .vinegar for the home. 



The small vinegar fly [Drdsopltiht ampeJophUa) was allowed to walk os^er sterile 

 cultural media under control conditions. Wherever its feet touched the media colo- 

 nies of acetic-acid germs developed. The digestive tract of this fly was also found to 

 contain large numbers of acetic-acid germs which were capable of growth in sterilized 

 cider. It is therefore ])elieved that this fly is of service in inoculating fruit juices with 

 the necessary germs for producing vinegar. They will also, however, carry spores of 

 molds and other organisms which give a bad flavor to vinegar. Therefore, the use of 

 pure cultures of vinegar ferments is advised. The author states that the station can 

 furnish these, upon api:)lication, to residents of the State. 



Pear vinegar containing 8.89 per cent acetic acid has been made at the station, and 

 apple vinegar which analyzed 6 per cent acetic acid within 4 months from the time 

 the apples were pressed. 



The essentials in making good vinegar are thus stated: "The barrels must be free 

 from must and mold, the depth of the liquid should not exceed the surface measure, 

 free air must l)e continually admitted, an even, warm temperature should l)e main- 

 tained, and, last but not least, the fruit that is used should be free from decay and 

 mold." 



Experiments iai wine making, H. Schellexberg {Jahrei^her . Vers. Stat. n. ScJnde, 

 Wddensiueil, 1899-1902, pp. 44-46). — Sal ammoniac added to a cask of pear cider at 

 the rate of 20 gm. per liectoliter conduced to a more rapid and complete fermenta- 

 tion of the must than when it was omitted. Pears just beginning to ripen ■were used. 

 No influence of the sal ammoniac on the taste of the wine could be detected. Apple 

 and pear wines filtered through a cellulose filter kept fresher during storage and 

 Avere more highly prized than wine clarified Ijy the addition of 60 gm. of gelatin per 

 hectoliter. A variety of sweet apple was gathered for cider when just beginning to 

 ripen. The flesh was still firm and somewhat acid. A given quantity of these 

 apples yielded more juice and produced a better quality of cider than apples of the 

 same kind gathered 3 weeks later when they had become more mellow. Wine that 

 had become flat in drawing off and clarifying was again made drinkable by the addi- 

 tion of carbonic acid. 



Composition and determination of differently prepared wines, W. Kel- 

 noFER {Jahrcsber. Vers. Stat. u. Srhiile, Wiidcnsireil, 1809-1902, pp. 99-103). — Analyses 



