Using a Refractometer For Brix and Beer Brewing
As you already know, a Refractometer is a helpful instrument in wine and beer industry. It helps us to track wine/beer fermentation. Even though the home brewers don’t use it often, they also can use it for tracking specific gravity. So, I thought of writing an article on how the home brewers can make use of the Refractometer for better results, and I will be using the BeerSmith as the meter conversion tool.
What is a Refractometer and how it works?:
This optical device measures the specific gravity of your beer and wort. Well, the advantage of using this device over a hydrometer is – you need only a small amount of liquid as the sample (just a few drops.) I am sure you have done the refraction test in your school days. When light travels through a glass of water, it bends at a certain angle. That’s refraction. The bending angle of light traveling depends on the type of medium. What if you add something to water like sugar? Well, then the bending angle will increase according to the sugar concentration.
While we can’t look at bending light and predict the sugar concentration, the Refractometer can. You get prisms, mirrors, and a light source in this device. The cheaper ones don’t have an internal light source, and the expensive ones have. So, you must hold the cheaper ones to a natural light source to get the readings. The scale used in most Refractometers is the Brix, which is a specific gravity measurement used by winemakers. You can also use the RI index scale. Once you obtained the index(s) readings, you have to convert them to standard specific gravity using a formula.
Calibrating a Refractometer:
As many other measuring devices, a Refractometer needs calibrating with distilled water before using. Open the sample plate and add some distilled water drops, then close the sample plate. When bubbles are there, the meter will find it difficult to give the measurements. Make sure the sample reach room temperature as most of the Refractometers are temperature sensitive. Well, now it’s dead simple. Hold the meter up to the natural light for taking the readings. Now adjust the meter until it reads zero with water in it. You might not get it right the first time, and which why I said: “until it reads zero with water in it.”
When beer brewing:
Well, it’s just similar to what you did when calibrating with distilled water. Just make sure the sample plate is dry/clean. Open the sample plate and add few wort drops. When the wort reaches room temperature, close the sample plate. Make sure no bubbles and hold the Refractometer to your light source.
Like every other measuring instrument, a Refractometer also has some limitations. This device can measure a clear liquid for sugar content, but the maltose is not clear making you do some adjustments when obtaining the readings. Also, the calculations involving Brix measurement conversion to a Plato or specific gravity can be complex for some users. Well, I would like to give you a tip at this point: Make sure you record the starting gravity of the wort for future reference.
Some final words:
A Refractometer is a useful device for measuring the sugar content in a liquid. As a home brewer, you also can make use of it. I have given some critical points to get accurate readings – make sure you remember them.