EBULLIOMETERS marked “cc.," instead of "ml.," are used, the same quantities should be 8 240.981 General characteristics. measured, the units of measure "ml.” Ebulliometers are instruments for and "cc.” substantially being the same. determining the percent of alcohol in The wine should not be diluted to a solution in water, but when proper di- greater extent than that necessary to lution is made because of dissolved bring the boiling point of the diluted sugar, they can be used to ascertain wine within 4 degrees of the boiling the alcohol content of wines. Alcoholic point of water, but one of the quantisolutions boil at lower temperatures ties of wine (100 ml., 50 ml., or 20 ml.) than water, and ebulliometers deter specified above should always be used. mine differences in boiling points, The degree of dilution required will which are referred to tables or sliding depend upon the sugar and alcohol scales to find the corresponding per content of the wine. Experience in centage of alcohol. Because boiling testing various types of wine will usupoints are affected by atmospheric ally indicate the degree of dilution rechanges, the boiling point of water quired. When a test shows a difference should be determined several times a of more than 4 between the boiling day. point of water and that of the diluted & 240.982 Kinds of ebulliometers author. wine, it is necessary to make another ized. test, using a lesser quantity of wine. In measuring the quantity of wine to be The Malligand (with shield), E.B. diluted for testing, a pipette of the Torino (with shield), Arnoldo-Sala (with shield), and L’Ebulliometer same size (capacity) as the quantity of wine to be diluted must be used and Levesque (with shield) ebulliometers the wine measured precisely to the have been approved for testing wine. mark. In adding water for dilution, All of these ebulliometers are of the care must be used to fill the flask preMalligand type, and the directions for their use are the same. The Juerst, cisely to the 200 ml. line. Inaccurate dilution is one of the principal causes Tag-Twin (with shield), Lefco, Salleron-DuJardin, and Braun ebulliom of incorrect tests. Because of the dilueters have also been approved for test tion, where 100 ml. of wine is used, the ing wine. Directions for the use of all percentage of alcohol indicated by the of these instruments are outlined in test must be multiplied by 2; where 50 the following sections. ml. of wine is used, the result must be multiplied by 4; and where 20 ml. of 8 240.983 Dilution of wine. wine is used, the result must be multiIt is a general rule that all wines plied by 10. should be diluted before testing so 8 240.984 Determining boiling point. that the difference between the boiling point of water and that of the Before each test to determine the wine is not greater than 4. The error boiling point of water or diluted wine, in the indicated percent alcohol will the boiler should first be drained of then be less than 0.1 percent regard- any liquid that may remain therein less of sugar content and for practical and then rinsed with a portion of the purposes is negligible. Dilutions liquid (water or diluted wine) to be should be made by measuring 100 ml., tested. After such rinsing, the boiler 50 ml., or 20 ml. of the wine with a pi- should be thoroughly drained before pette and running it into a 200 ml. another portion of the material (water narrow-necked, volumetric flask. Then or diluted wine) to be tested is poured add sufficient water of the same tem- into the boiler. The rinsings should perature as the wine to bring the not be used to make the test. In deterliquid to precisely the 200 ml. mark on mining the boiling point of water, the flask. This gives a sufficient quan- when steam comes out of the top of tity for the test and for rinsing the the instrument, which indicates that boiler prior to making the test. The the water has started to boil, watch wine and water should be thoroughly the thermometer. The point at which mixed. When pipettes flasks the mercury remains constant is the or boiling point of the water. In determining the boiling point of diluted wine, when the mercury in the thermometer begins to rise, readings should be made every 15 seconds and written on a slip of paper. The point at which the mercury remains stationary for several consecutive observations is the boiling point of the diluted wine. Readings should be estimated between the smallest divisions of the thermometer scale. For example, if the thermometer scale is in tenths of a degree and the top of the mercury column is between two of the lines, the difference should be estimated and read accordingly, as 98.95 degrees, and such reading used in referring to the table or sliding scale. Inaccurate thermometer readings are a principal cause of incorrect results. placed as soon as it becomes too short to reach well down into the alcohol. The flame of the lamp (or gas burner, if used instead of the lamp) should be shielded from drafts and should be adjusted so that about eight minutes elapse before the thermometer begins to rise when the boiler contains water or diluted wine. Do not force rapid boiling. Do not continue heating after the condenser has become very warm. BRAUN EBULLIOMETER $ 240.987 General. The percentage of alcohol content is read by means of the alcohol percentage calculator included with the instrument. The revolving disk of the calculator is graduated in degrees centigrade corresponding to the graduations on the thermometer. The graduations on the outer circle of the calculator represent percentages of alcohol by volume. Attach the condenser to the threaded opening on top of the ebulliometer. Place the instrument on a level table and shield it from drafts which may cause unsteady temperature conditions. 8 240.985 Care of instrument. Cleanliness of the boiler is important because scale or residue will cause bumping and produce rapid fluctuations of the thermometer, which make correct readings impossible. The boiler should be flushed several times with water after each determination. After about 50 determinations, an approximately 2 percent solution of caustic soda should be put in the boiler and boiled for about one minute. The boiler should then be flushed thoroughly with water, after which two determinations of the boiling point of water should be made. If these readings do not agree, more washing of the boiler with water is required. When attaching the condenser to the boiler, be sure the washer is placed on the connection between the condenser and the boiler, and see that the condenser is screwed tightly to the boiler before using; otherwise, leakage will occur and the reading will be incorrect. 8 240.988 Determination of boiling point of water. Fill the graduated measuring glass with water up to the line marked "25 ml.” Pour this quantity of water into the instrument through the opening provided for the thermometer at the top of the ebulliometer. Now place the thermometer in this opening, being sure that rubber stopper fits snugly. Fill the condenser jacket with water. Light the alcohol burner and place it in the fork of the ebulliometer directly under the circular chimney. Adjust the length of the lamp wick so that the point of the flame will hit the horizontal tube. The rising temperature of the water will be indicated by the thermometer. When the water reaches its boiling point the thermometer reading will remain constant. Read this boiling point temperature accurately. Take the calculator and set the revolving disk so that the figure on it corresponding to the boiling point of the water is exactly opposite the zero mark on the outer circle. Clamp the disk firmly in this position 8 240.986 Alcohol lamp. The alcohol lamp must be kept clean and well filled with denatured alcohol. From time to time the lamp must be emptied, cleaned out, and refilled with clean denatured alcohol. The wick should be kept in good condition. The tip should be trimmed where it becomes burned through a scanty supply of alcohol, and the wick should be re N.B. The correction for indications between 21° and 30° Brix and 50° and 70° F. temperature may be made by adding 0.005 to each correction given in the above table column 21°, for each increase in degree Brix. For instance, 25° Brix 79° F. correction to be added to column 21° and 70°, 0.02 +0.38=0.40. (T.D. 6880, 31 FR 3456, Mar. 5, 1966. Redesignated at 40 FR 16835, Apr. 15, 1975) 8 240.974 Explanation of Table III. Where the temperature of the juice is other than 60 degrees Fahrenheit, the saccharometer reading of the juice must be corrected for temperature according to this table, in order to determine the true Brix of the juice. When the temperature of the juice is below 60 degrees Fahrenheit, the correction shown by the table should be deducted from the saccharometer reading, and when the temperature of the juice is above 60 degrees Fahrenheit the indicated correction should be added to the reading. For example, if the saccharometer reading is 20 degrees Brix and the temperature is 75 degrees F., Table III shows that correction for this reading and temperature is 0.58, which should be added to the reading. Therefore, 20° +0.58° = 20.58° total solids. 8 240.977 Example. Find the amount of dry cane sugar required to raise the total solids content of 500 gallons of juice from 12 degrees Brix to 25 degrees Brix, and the resultant gallonage. (a) Find the figure 12 in the lefthand column of Table IV. (b) Opposite the figure 12, the pounds of cane sugar required for each gallon of juice is found in the second column, and is 1.5122. (c) 1.5122 x 500=756.10 pounds of cane sugar. (d) Opposite the figure 12, the resultant gallonage for each gallon of juice is found in the third column and is 1.1127. (e) 1.1127 X 500=556.4 gallons of corrected juice. (T.D. 6395, 24 FR 5544, July 9, 1959. Redesignated at 40 FR 16835, Apr. 15, 1975) 8 240.975 Total solids in wine. Total solids content of wine means the degrees Brix of the dealcoholized wine, and is approximately equal to the percent of solids by weight in the dealcoholized wine. The total solids may be determined by dealcoholizing a measured volume of wine, restoring to the original volume with water, and determining the degrees Brix of this solution according to the instructions in $ $ 240.972 to 240.974. 8 240.978 Table IV, showing pounds of sugar required to raise 1 gallon of juice to 25 degrees Brix and the resultant gallonage. Table IV shows the pounds of cane or beet sugar and the pounds of commercial dextrose required to raise 1 gallon of juice to 25 degrees Brix, and the resultant gallonage. Where other pure dry sugars having a dextrose equivalent of not less than 95 percent on a dry basis are used, the pounds of commercial dextrose required to raise 1 gallon of juice to 25 degrees Brix shall be used to determine the pounds of such other pure dry sugars required to raise 1 gallon of juice to 25 degrees Brix. (T.D. 6880, 31 FR 3456, Mar. 5, 1966. Redesignated at 40 FR 16835, Apr. 15, 1975) USE OF PURE DRY SUGAR OR LIQUID SUGAR TO CORRECT JUICE (OTHER THAN GRAPE) TO 25 DEGREES BRIX 8 240.976 Instructions respecting the use of pure dry sugar. Section 240.978 (Table IV) shows the pounds of pure dry sugar required to raise the total solids content of 1 gallon of juice to 25 degrees Brix with commercial dextrose (1 molecule of water of crystallization), cane or beet sugar, or other pure dry sugars having a dextrose equivalent of not less than 95 percent on a dry basis. This table shall be used in determining the quantity of pure dry sugar that may be added to fruit and berry juice to correct natural deficiencies in the juice. |