How Do I Use A Hydrometer


Being a total novice at home brew, I would like to know how to properly use a hydrometer. The instructions that came with the one that I bought are difficult to understand, to say the least.

Do I just bung the hydrometer into the bin of fermenting lager – and what should I be looking for?

I know about the specific gravity being below a certain number – but how do I find it? What if there is more than one number highlighted? Thanks for your help!


The hydrometer is a very useful tool in home brewing. It will allow you to know your starting gravity is & final gravity giving you the overall alcohol content of your brew.

  1. Drop a sanitized hydro into the fermenter or use the tube that hopefully came with yours after you finish brewing and cool the wort
  2. Spin the hydrometer to dislodge any air bubbles and take a reading where the wort lines up on the stem and record the number
  3. Do the same thing about 14 days after fermentation although you can check it at various points in between
  4. Then subtract the numbers and multiply that with .129

This will give you the alcohol content. It will also tell you it’s time to bottle as long as you have achieved your finish gravity…


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  1. Pingback: How To Read My Hydrometer | Beer Brewers Guide

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