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Gravity of beer is the percentage of gravity of the wort used as raw material. If you understand even more in detail – the pure concentration of solids can be easily obtained by drying the drink.
On the label, the gravity of the beer is next to the alcohol indicator, so it’s quite difficult not to notice it. However, one should be aware of the differences in measurement systems: Russian producers, as well as brewers from Europe and the USA, use the traditional measurement system with a hydrometer (a device that shows the percentage of sugar in a drink).
But in some countries (England and the states under its protectorate) they use a hydrometer (they measure the density of water, not solids).
Method for measuring the density of beer
As a rule, the density of beer is measured twice: at the start of fermentation, and also immediately before bottling.
The measurement process by the classical method is as follows:
Pour some beer into a narrow container.
Immerse the hydrometer in the liquid.
We wait until the bubbles evaporate from the beer.
We take measurements of the device.
The result should be read strictly at eye level, otherwise there is a high risk of obtaining inaccurate information. By the way, most hydrometers are designed for average room temperature (20 degrees Celsius), and measurements should be taken in a room that meets this condition.
In case of doubt about the exact indicator of air temperature, you should examine the scale of the device – the manufacturer must put the appropriate marking on it.
If during the first measurement it is allowed to take readings almost immediately, then before bottling it is necessary to make sure that the density remains unchanged for a day and a half. This allows us to assert with absolute certainty that the fermentation process is over.
After completing the measurements, the hydrometer should be wiped dry and then stored in a special case where moisture does not penetrate.
Average gravity in beer
At the time of the first and second measurement, the density of the beer will differ. This is due to the fact that the sugar initially found in the drink gradually turns into alcohol.
For example, light beers at the first measurement can boast a density of about 1.037 (from 9 to 10%), and at the time of bottling, the figures will drop to one (2%).
If the final gravity exceeds 2.5%, the beer is considered unformed and has a slight sweetish tint (due to not completely dissolved sugar). To fix this, some yeast is usually added and the process repeated.
There are also sweet varieties, such as Barley Wine, whose production technology involves stopping the fermentation process at three percent (1.014 units).
How Beer Gravity Affects Alcohol Percentage
In fact, the density of beer and the amount of alcohol in the drink are very closely related: the more sugar in the raw material, the more alcohol is formed in the final product.
Of course, the alcohol index also depends on many other criteria (exact adherence to fermentation technology, quality of raw materials, etc.), but it is the density of the must that can be considered the main one.
Relevance: 13.11.2019
Tags: beer, cider, ale