If you’ve been homebrewing for any amount of time, you already know to expect the unexpected. You might get your hands on a bad batch of yeast and your beer doesn’t ferment. Or your yeast might ferment so quickly you worry it didn’t ferment at all. Or Uncle Ernie might be far loopier than he should be after only one beer.
This is where your hydrometer can save the day (and your uncle’s liver). It’s an often-overlooked step in brewing, even though it’s quick and painless. Get in the habit of using it during every batch to determine if your fermentation has finished, maintain consistent results, and measure your estimated alcohol by volume (ABV).
Although you could run into occasions where a batch can’t be saved, you can record your mistakes and make sure they’re not repeated next time. Or, in the case of your ABV being far higher than expected, you can make smaller pours or move to a session beer after your first glass.