Using a Hydrometer (2024)

FAQs

How do you read a hydrometer results? ›

Read the hydrometer scale at the lowest point of the liquid's surface. The surface of the fluid may cling to the hydrometer and the container walls, forming a curve called a meniscus. Look for the scale mark on the hydrometer level with the lowest point on the fluid's surface.

If you look at a hydrometer and think about how these funky devices are made, it becomes apparent that calibration errors are probably pretty common, either during manufacturing or during handling when the calibration paper may be jostled.

To do this, take a sample of distilled water at the temperature of the hydrometer's calibration. If the hydrometer reading is 1.000, your instrument is correctly calibrated. If it is too high, you can use a file to shave off some of the glass from the bottom of the hydrometer until it hits 1.000.

Take down the number seen on the hydrometer. The reading should be below 1.010, and if it exceeds this, then you should take your time and wait for some more days before taking another reading. It could be because the fermentation process is still going on.

The hydrometer and liquid should be at the temperature of the surrounding atmosphere to prevent changes in density during the testing. To ensure uniformity of density and temperature, the liquid should be completely stirred shortly before the observation is made.

The ABV can we worked out really simply by taking the start gravity from the finish gravity and dividing this figure by 7.362. For example the starting point for our wine is 1.080 and this ferments down to 0.990. The drop is 90 points. This divided by 7.362 is 12.23% ABV.

In the standard hydrometer scale, known as the specific gravity scale, distilled water equals 1.000, the initial point of measurement. Liquids lighter than water are scaled below 1.000 specific gravity, and liquids heavier than water are scaled above 1.000 specific gravity.

Calibration Temperature: Hydrometers are calibrated to be used at a specific temperature. Our standard Triple Scale Hydrometer is calibrated at 68 degrees. If your hydrometer is properly calibrated, it should read 1.000 when floating in pure water (distilled or reverse osmosis water).

You either don't have enough beer in the tube or the hydrometer is stuffed.

What could be possible sources of error in reading a hydrometer? ›

Hydrometer Calibration. While not compensating for temperature is the most common source of error when using a hydrometer, another is assuming that the hydrometer is accurate to begin with. Many unfortunately are not. All hydrometers should therefore be calibrated before they are used for the first time.

Using a hydrometer is a straightforward process that involves submerging the instrument in the liquid you intend to measure. The hydrometer will float at a level directly proportional to the liquid's specific gravity.

For most analog hygrometers, simply adjust the needle to read 75% on the gauge by turning the screw on the back of the hygrometer with a small screwdriver. Many digital hygrometers can be adjusted with a button.

Hydrometers are calibrated to work at a certain temperature, and readings taken outside of that range can be low or high depending on the temperature.

A hydrometer is placed in water and then in a number of carefully prepared sugar solutions of different known concentrations. The stem emergence in each solu- tion is measured. Then a line graph is prepared by plotting the stem emergence of each solution versus its corresponding concentration.

Ideally, you want to add enough beer to your sample tube, that when the hydrometer is added, the fluid level fills up the tube almost completely. Spin the hydrometer to eliminate any air bubbles that might cling to the side of the hydrometer.