Standard Reference Method, or SRM, is a method of measurement used to determine and define a beer’s color on a numeric scale using a photometer or spectrophotometer. The color of a beer is an important factor when judging a beer’s overall quality. Different beer styles are expected to fall into a specific color range, and the SRM is a way of measuring that. The lighter the color of a beer, the lower the corresponding SRM value will be, and, as expected, the darker the beer, the higher the SRM value will be. Beers range anywhere from 2 to in excess of 40 on the SRM scale. Below is a chart featuring the SRM value on the left with the approximate color and beer style example to the right.
West Coast Brewer SRM / Standard Reference Method Beer Color Scale
A hydrometer is an instrument used to measure the specific gravity of liquid in comparison to pure water. The hydrometer is important because it allows a brewer to determine several things:
- When the mash is no longer contributing sufficient levels of sugar during a sparge
- How much dissolved sugar is in the finished wort
- If your beer has under or over fermented
- Brew house efficiency
- Original gravity
- Final gravity
- Fermentation progress
- Fermentation completion
- Alcohol by volume.
Below are three examples of different hydrometers that are available to brewers, including one used for determining your final gravity.
Beer brewing hydrometers for taking specific gravity readings such as original gravity and final gravity.
Here is the final gravity reading from a hydrometer that also registers temperature so that corrections can be made if the beer is too hot or too cold.
Beer hydrometer showing a final gravity reading.