How To Use A Hydrometer

Posted by admin 10/04/2016 0 Comment(s) Articles,

How to Use a Hydrometer



The above is a scientific tool, and it is used to measure the alcohol content present in the mash. The work of the device primarily measures liquid density in water relation. Distilling and brewing hydrometers make the two types of the hydrometers available. Their calibration is different, and that is why it is advisable to have both of them when making spirits. A brewing hydrometer should not be used when measuring the product to know the final proof; on the other hand, when making mash, you should not use spirit hydrometer. Here, we are going to talk about the hydrometers used for brewing, and the information is essential to brewers.


What Hydrometers Measure


The sugar amount present in the wash and mash is what mainly the brewing hydrometers measure. It will float depending on the amount of sugar that is in the mash. For instance, if it is high, the hydrometer will float higher. After fermentation takes place, the paste (the mash) becomes the wash and at this point, another reading is taken so as to know the amount of sugar that was turned into alcohol by the yeast. If the difference is big, then it means that the alcohol level in percentage is significant.

Many hydrometers have three scales and in this article, we are majorly looking at specific scale gravity.

  • The Brix scale is in most times used to make wine.
  • The Potential alcohol scale which estimates the alcohol in the mash
  • The Specific Gravity scale which is useful for brewing


Original Gravity Determination


Determining original gravity is carried out so that the amount of sugar in the mash is known. Typically, this happens before fermentation takes place and before you add yeast to your mash. As we have already seen, the original gravity determines the amount of sugar that is contained in the pulp and gives an estimation of the amount of alcohol that is likely to be produced if the process does not go haywire.


There is a variation of the original gravity since it depends on the use of the recipe. Giving an example, corn whiskey which is popular among brewers starts at 1.055 and the production of wash and alcohol content ranges from 6% to 7.5%.

It is important that you take down the original gravity of the mash so that you can avoid forgetting. It is possible not to remember the reading by fermentation stage especially in a situation whereby you are carrying out many batches of fermentations at the same time. It is important to note that the first reading will not help you know the final alcohol content, and that is why another reading should be taken.

The original gravity reading is taken once the steps listed are completed.

  • A beer sampler should be used and a jar filled with liquid to almost full.
  • The wine hydrometer should then be dropped in a gentle manner into the pot. The hydrometer should be span in a way that it does not stick to the sides, and it will finally float.
  • Take down the reading that you see on the barometer.


Determination of Final Gravity


The density of the liquid is measured by the final gravity like the original gravity. It should be noted that if the process continued without any problems, then the density of the liquid should be lower because the yeast ate the sugar present in the liquid during the process of fermentation. The alcohol content will be the difference between the original gravity and final gravity.

The steps given below are for the mash that has been fermented for one week. Meanwhile, if this is the case with your mash, the airlock seems to have fewer activities or even no activities going on. In case you notice there is a lot of bubbling then you should just wait since this means that there is work going on.

  • Beer sampler should be used and a jar filled with liquid to almost full
  • Slowly put the beer hydrometer into the jar and gently spin it ensuring that it does not stick to the far walls. It will float on the liquid.
  • Take down the number seen on the hydrometer. The reading should be below 1.010, and if it exceeds this, then you should take your time and wait for some more days before taking another reading. It could be because the fermentation process is still going on. The readings should continuously be taken until it is constant and there is no change.


Reading the Hydrometer


The calibration of the hydrometer is at 60 degrees. There is the need to adjust it to actual reading in case you are taking a reading of your mash that is above 60 degrees. One can get help from online calculators so as to convert the readings taken either below or above 60 degrees.



Determination of Alcohol Content of Wash


So that you can be able to determine the alcohol concerning volume, then all you need is your original reading and final reading. Taking the example of what we did above the sample was 1.090 while it finally fermented to become 1.010. The math can simply be done as below;

Subtraction of Final Gravity from the original one

Multiplication of the difference by 131

1.090 minus 1.010 equals 0.08.

0.08 X 131= 10.48

The content of alcohol in the wash as seen in the above calculation is 10.48%


The Ideal Starting Alcohol Percentage For Wash


There are some instances where some recipes produce lower starting alcohol while some recipes produce higher starting alcohol. The combination of turbo yeast and a ton of sugar is what can lead to the production of starting alcohol percentage of even more than 20%. It is good to note that if you are after producing the best alcohol that has an excellent taste, the best recipes to use are those that have to start alcohol ranging from 5-8%. The alcohol produced will be around 10% or more of the content of alcohol.