# Question: How Does Temperature Affect Gravity Reading?

Hydrometers are used to measure the density of dissolved solids in our wort or beer.

Most brewers use the specific gravity scale which is actually a dimensionless number that is a ratio of the density of the liquid to that of pure water which is defined to have a specific gravity of 1.000..

## When should I take OG reading?

Your original gravity (OG), which is taken just before pitching your yeast and after the wort has chilled. Make sure you make any temperature adjustments to it before recording it. Follow the instructions for your hydrometer or refractometer for this.

## How do you correct specific gravity?

ADJUST BY ADDING SUGAR Add corn sugar/invert sugar/ to increase the gravity. To calculate the amount needed, take an initial gravity reading, then subtract that from the specific gravity you wish to begin with. The difference will determine approximately how much sugar to add (use table below).

## How do you adjust the original gravity?

There are several possible means of adjusting the values, depending on whether the actual volume and gravity are above or below the targets. Diluting the wort with water will increase the volume and decrease the gravity, both before and after the boil. Adding fermentables will increase the gravity.

## Does temperature affect hydrometer readings?

Many brewers forget that hydrometer readings are temperature dependent. Each one has a reference temperature (usually 60°F/15.5°C or 68°/20°C); if your sample is significantly warmer or colder, your reading will be off. For example, wort at 100°F (38°C) will read as 1.056 on a 60°F hydrometer when it’s actually 1.062.

## What can affect a hydrometer reading?

Suspended solids in the sample can effect the boyancy of the hydrometer. If a cloudy, murky sample is tested, filtered, then re-tested… there can be a noticeable difference in the reading depending on the amount of suspended solids and the density of the solids themselves.

## How do air bubbles affect specific gravity?

Density or specific gravity (SG) is affected by entrapped air bubbles in the liquid under test. … Under pressure the air will dissolve better into the liquid and any bubbles that are left undissolved will be compressed to a fraction of their original size.

## Does API gravity change with temperature?

API gravity increases with increasing temperature, while specific gravity decreases with increasing temperature. … This means that the volume of a petroleum liquid increases with increasing temperature, and that a density number always must be given with the measurement temperature.

## Why is my final gravity so high?

Brewers should always examine all possible causes of high final-gravity readings, such as improper aeration of the wort, low fermentation temperature, lack of viable yeast, or too many dextrins. … As when fine-tuning original gravity, combining extract syrup with dry extract may solve this problem as well.

## How does temperature affect hydrometer?

A quick word about the temperature: Modern hydrometers are typically calibrated to read at 20C and a higher or lower temperature liquid affects the accuracy. … A warmer temperature of 32C (typical of warm wort) would give a difference of plus 1.003. Our reading of 1.040 would actually be 1.043.

## What is the ideal temperature for specific gravity determination?

39.2oFThe term “Specific Gravity” (SG) is used to define the weight or density of a liquid as compared to the density of an equal volume of water at a specified temperature. The temperature used for measurement is usually 39.2oF (4oC), because this temperature allows water to assume its maximum density.

## Is density equal to specific gravity?

Density = Mass / Volume Specific gravity is the density of a substance divided by the density of water. Since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density (but without any units).

## How does temperature affect specific gravity?

Can temperature affect specific gravity? Yes, it can. When using water as a reference for establishing specific gravity, it is almost always assumed that the water is at 4°C, when it’s densest. … Water itself becomes less dense as it becomes warmer until it evaporates and becomes steam vapor at boiling point.

## What temperature is gravity reading?

Brewing Tools: Hydrometer Temperature Correction Hydrometers are built to provide an accurate reading when your wort is 59°F (15°C).

## Does specific gravity of oil change with temperature?

Each colored line represents a crude oil with a given density at a given temperature. If the temperature changes, the density of the crude oil changes along the colored line.

## Is specific gravity dependent on temperature?

Specific gravity is dependent on the temperature, and most of the values found in the literature refer to STP conditions. Although the two terms often are used interchangeably, there is a technical difference between specific gravity and density. Density is defined as the mass per unit volume of a substance.

## Does the density of oil change with temperature?

For example, honey and oil tend to flow better at higher temperatures. … In general, the liquids tend to expand when their temperature increases. For example, the same mass of boiling water occupies more volume at 100 degrees Celsius than at 20 degrees Celsius. Therefore, increasing temperature decreases density.

## Is oil less dense than water?

Since the oil is lighter, it is less dense than water and floats on water.