How does a refractometer work brewing

If not, you can adjust the refractometer by removing the small plastic cap which covers the calibration screw and using a small screwdriver to turn the screw see photo. Once you are happy that the refractometer is calibrated, you should replace the plastic cap before moving on to the next step. This is important since, if there is any distilled water left on the prism when you add your sample of wort, it will affect the measurement. Before taking a sample, make sure that the pipette, metal spoon or wine thief have been thoroughly sanitised and left to dry before dipping it into the wort.

Poor sanitation is the easiest way to mess up a batch of beer. Open the transparent plastic flap which covers the prism, place a few drops of wort on the prism and then close the flap again so that the sample is spread evenly across the prism.

Hold the refractometer up to the light and look through the eyepiece. If necessary, adjust the focus using the focusing ring. Clean and dry the prism with distilled water and a soft cloth to remove all traces of wort before placing the refractometer back in its case.

As we have seen, refractometers are very easy to use but, as with all precision instruments, there are a few factors which you should bear in mind. Refractometers measure the percentage of sucrose a type of sugar in water to give a reading in Brix. Wort is made up of a mixture of different sugars, mostly glucose but also maltose, fructose and sucrose. These sugars have a slightly different refractive index than sucrose. This tiny difference in refractive index causes the Brix reading to be slightly inaccurate.

The so-called Wort Correction Factor is used to ensure that the measurement is as accurate as possible. For most refractometers, the correction factor is around 1. To calculate the correction factor, you take a sample of unfermented wort and compare the Brix reading from your refractometer with the Brix or SG reading from your hydrometer. You can download a spreadsheet from Brewers Friend, which calculates the correction factor. To get the most accurate measurement possible, you should always take at least two or three measurements.

One of the advantages of using a refractometer instead of a hydrometer, especially when brewing small batches, is the fact that you only need to take a very small sample of wort or beer. The most straightforward example of refraction is by looking at a full glass of water. When you view the glass from the top, the bottom of the lens may seem like it is raised higher than it is. When you place a straight object like a spoon or a knife in the glass, the utensil will look bent as you view it from the side.

The refractometer works on a similar principle. When you place the sample of the wort — the liquid extract from the mash — on to the refractometer, the light that passes through it will refract at different angles depending on the amount of dissolved sugar in the sample.

The refracted light will brighten a scale with a range of varying wort densities. By looking through the eyepiece of the refactor, you are easily able to read the density of the wort from the scale.

Brix is the sugar content that is in a liquid solution. Brewing alcohol is just the conversion of sugars into ethanol and carbon dioxide. Being able to calculate the sugar levels in wort allows brewers to figure what the alcohol content of the brew will be after fermentation. This value is based on a range of one to As brewers use their refractometer to measure the degrees Brix of their wort, they can estimate the potential value of its alcohol content by multiplying the value by 0.

If the wort had a value of 17, the possible alcohol content would be approximately The value of the alcohol content is approximate as other factors also determine the efficiency of the fermentation. The conversion factor of Brix to potential ABV can range from 0. Brewers will take sample readings throughout the fermentation process.

Sample readings allow them to measure mash efficiency, recipe targets, the progress of fermentation, and when fermentation has finished. Some brewers may prefer to take specific gravity or Plato measurements instead of Brix, but all units are used to measure the same thing. If a brewer takes a Brix measurement, it can be converted to specific gravity or Plato easily with simple calculations.

Before you begin using a refractometer, it needs to be calibrated, as many technical measuring tools do. Calibrating a refractometer is a quick and easy process. Lifting the sample plate sometimes called the daylight will allow you to place a few drops of distilled water on the glass. Once the distilled water is added, the daylight plate is closed, and the water will spread across the sample plate.

There must be no bubbles within the sample. Refractometers are sensitive to the temperature, which will require the sample to be warmed to room temperature unless the model automatically adjusts for temperature. Once the sample has reached the ideal temperature, the refractometer is held to the light to take a reading. Many refractometers will have a calibration knob that will allow the calibration setting to be adjusted. The refractometer should be corrected to say zero with distilled water on the sample plate.

It may take a few tries, but once the refractometer is zeroed out, it is ready to be used. After the refractometer has been calibrated, it is ready to be used in the beer-making process.

The use of a refractometer in brewing is similar to the steps used for calibrating the tool. The sample plate is opened once again for a sample of the wort to be added. The plate needs to be clean and dry. A few drops of the wort are placed on the sample plate. If the wort sample is hot, it will need to be cooled to room temperature around 68 degrees Fahrenheit. The sample plate is shut, bubbles are released, and the refractometer is held up to a natural light source.

The reading of the refractometer is simple. The calibrated scale will show you the result through the eye viewer. Also they look cool. The refractometer operates on the optical principle that light passing through a liquid refracts at different angles according to the density of that liquid.

Rephrasing that statement, light passing through a small sample of wort refracts at different angles according to the concentration of dissolved sugar in that wort.

The refracted light illuminates a scale, upon which is printed a range of wort densities. You peek through an eyepiece and read the wort density from the scale. ATC is a convenience well worth seeking out because a couple of drops of even boiling wort will quickly cool to within this range. Most refractometers available to homebrewers these days are dual-scale instruments that report results in both Brix and specific gravity units of measurement.

Brewers usually prefer to express density in either specific gravity or Plato units, while winemakers often prefer Brix.