Use of Pyknometer/Saccharometer
Due to the extremely similar use of the two, we will use a sugar meter as an example. According to the principle of the sugar meter, we know that the reading of the sugar meter needs to be measured at standard temperature, so we can use a sugar meter with attached temperature, so that if it is not at 20 ℃, it can be directly compensated for temperature.
The attached temperature sugar meter measurement is a float meter made based on the principle of liquid density meter. The lower the relative density of the liquid, the deeper the densitometer sinks. The thin rod of the sugar meter is engraved with a mass percentage scale.
(1) The cleaning of the sugar meter should be done with the tested wort, and should not be washed with water or other liquids to avoid changes in wort concentration and obtain accurate measurement results as much as possible. Similarly, in order to mix the wort temperature evenly in the measuring cylinder, the spiral stirring rod used should also be rinsed with the measured wort.
(2) Cooling of wort: Take a small amount of wort and place it in a metal cylinder. There is a metal cooling sleeve outside the cylinder, which can cool the wort to around 20 ℃ because the sugar meter is calibrated at 20 ℃. Of course, during cooling, it is important to ensure that the wort is not diluted and to avoid an increase in concentration caused by the evaporation of water in the wort.
(3) Carefully grasp the upper end of the sugar meter and slowly place it on the estimated scale. Wait for the sugar meter to stabilize, then read the displayed value from the convex scale where the wort and sugar meter come into contact.
Then check the calibration value corresponding to the temperature scale in the lower half of the sugar meter. If the temperature of the measured wort is higher than 20 ℃, add the calibration value to the displayed value on the sugar meter; When the temperature is below 20 ℃, the displayed value of the sugar meter must be subtracted from the calibration value. If the accuracy meter reading is 11.6 ° P and the correction value at 20 ℃ is 0.2 ° P, then the wort concentration is 11.6-0.2=11.4 ° P, which means that at 20 ℃, 100kg of the wort contains 11.4kg of extract.
Note: Although the attached temperature sugar meter comes with temperature compensation, temperature compensation requires time and should not be too high. It is recommended to control the wort temperature as much as possible at around 20 ℃ during measurement.
At the same time, when measuring the fermentation broth, it is necessary to remove carbon dioxide from the fermentation broth, otherwise it will also have a lot of impact on the measurement results.
