A hydrometer is a vital equipment in beer brewing, used to determine the specific gravity (or density) of liquids such as beer, wort, wine, and water. It is especially important during the fermentation stage, where brewers can monitor the process, spot problems, and make required modifications.
The Role of a Hydrometer in Brewing
The fermentation step is critical in the brewing process because it converts carbohydrates in the wort into alcohol and carbon dioxide using yeast. A hydrometer gives vital information during this stage by measuring specific gravity, which reflects the fermentation’s progress and health. Brewers can guarantee that their beer is of great quality by following these parameters and making modifications as needed.
How to use a hydrometer?
Using a hydrometer is simple if you follow these steps:
1. Retrieve the sample and insert the hydrometer.
Before pitching the yeast, take your initial measurement after the wort has cooled. This first value, known as the original specific gravity (OG), establishes the foundation for your fermentation. To get this reading:
Using a beer sampler, take a sample of the wort and transfer it to a test jar or graduated cylinder.
Ensure that there is enough liquid to completely suspend the hydrometer.
Place the hydrometer in the wort and let it to float freely.
Wait until the liquid is stable and all air bubbles have been expelled.
To get an accurate reading, center and hold the hydrometer vertically.
2. Take the Original Gravitational Reading.
On the hydrometer scale, read the specific gravity of the liquid where it reaches the airline. Typical OG readings for wort range from 1.035 to 1.060. Compare your result to the predicted OG listed in your brewing kit to confirm it falls within the acceptable range.
3. Take into account the temperature
Hydrometer measurements are normalized at 15°C (59°F). If your wort is at a different temperature, you should modify the reading accordingly. To obtain an exact specific gravity, use a temperature correction chart to calculate the “delta gravity” and then add it to your initial result.
4. Proceed as usual for one last Gravity Reading.
As fermentation approaches completion, take another hydrometer measurement to determine the final gravity (FG). Beer’s FG levels typically vary from 1.015 to 1.005, accounting for 1/4 or 1/5 of the OG. Comparing the FG and OG determines the alcohol concentration and ensures that fermentation is complete.
