The principle and use of sugar meter
Some craft brewers have come to inquire about how to use the Brix meter, and even some craft brewers who have already made commercial brews have little knowledge about measuring Brix. The accurate measurement of sugar content is an important data reference for the subsequent precise control of each node in the brewing process. In today's content, we will introduce the instruments and processes for measuring sugar content.
measuring instrument
Common instruments for measuring sugar content include sugar meter, hydrometer, hand-held refractometer, etc.
If we want to understand and use these instruments, we need to understand the relationship between sugar content and wort concentration.
Wort contains a lot of sugar, protein and various vitamins, but sugar accounts for the majority in wort, so the concentration of wort is about equal to the sugar content in wort. This is also the original wort concentration that I often refer to as the sugar content of the original wort.
Principle of Hydrometer/Brix Meter
The principle of hydrometer is the same as that of glucometer, which measures the specific gravity of a specific solution by its floating height in the solution, but the unit of glucometer and hydrometer are different.
The estimation formula of the unit: [(Specific gravity-1)*1000]/4=Brix
For example, the specific gravity of wort is 1.040. According to the conversion formula, the sugar content is about 10p. The relative density is measured, which is the density of the solution relative to water. The specific gravity of water is 1.000. The reading refers to the standard temperature (20 degrees Celsius). Density is temperature dependent, so hydrometer readings should be corrected to specific gravity at standard temperature.
Use of Hydrometer/Brix Meter
Since the use of the two is very similar, we take the Brix meter as an example. According to the principle of the sugar content meter, we know that the reading of the sugar content meter needs to be measured at the standard temperature, so we can use the sugar content meter with attached temperature, so that if it is not at 20 °C, the temperature can be directly compensated.
Brix meter with temperature measurement is a float meter, which is made according to the principle of liquid density meter. The lower the relative density of the liquid, the deeper the densitometer sinks. A mass percentage scale is engraved on the thin stem of the Brix meter.
(1) Cleaning of the Brix Meter The Brix meter should be cleaned with the wort to be tested, and cannot be washed with water or other liquids to avoid changes in the concentration of the wort and obtain accurate measurement results as much as possible. In the same way, in order to make the temperature of the wort in the measuring cylinder evenly mixed, the spiral stirring rod should also be washed with the wort to be measured.
(2) Cooling of wort Take a small amount of wort and put it in a metal cylinder. There is a metal cooling jacket outside the metal cylinder, which can cool the wort to about 20°C, because the sugar meter is calibrated at 20°C. Of course, during cooling, it is necessary not only to ensure that the wort cannot be diluted, but also to avoid the increase in concentration caused by the evaporation of water in the wort.
(3) Reading of the Brix Meter Carefully hold the upper end of the Brix meter, slowly put it on the scale of the estimated value, wait for a while, after the Brix meter is stable, read the thin tube from the convex scale where the wort and the Brix meter are in contact display value.
Then check the correction value corresponding to the temperature scale of the lower half of the sugar meter. If the temperature of the measured wort is higher than 20°C, add the correction value to the displayed value of the sugar meter; when it is lower than 20°C, the displayed value of the sugar meter must be Subtract the correction value. If a certain accuracy meter reading is 11.6°P, and the correction value under 20°C is 0.2°P, then the wort concentration is 11.6-0.2=11.4°P, that is, at 20°C, 100kg of the wort contains 11.4kg Leachables.
