Tuesday Questions: Well, Aren’t You Handy…

by Cooper Young

It looks like we have a single search term today. It’s the sort of thing I’m eager to provide an answer to because I know whoever came here looking for one didn’t find one here. So, we have:

make shift hydrometer tube

A Note: I’m going to assume you’re asking how to make one. The only other reason I can imagine you would search for this would be if, say, it somehow ended up in your top searches on your blog and you wanted to know what the heck was going on. I’m not going anywhere near that rabbit hole.

I…well, I never would have thought that was a thing. At first I assumed that by “hydrometer tube” you meant a test jar (which is really just a graduated cylinder or something similarly shaped), so my initial answer was “anything that’s deep enough to float it, genius”. Further research (yes, I do that), informs me that making one’s own hydrometer is actually a real thing some people attempt. I’m assuming these people either break them by the handful or live somewhere where they aren’t six damn dollars.

Now, really, that’s unfair of me. I did make my first four batches of mead in milk jugs and went without a hydrometer, homemade or otherwise, for about a year, so I really can’t judge. I suppose that’s just my knee-jerk reaction to people making the same mistakes I did. Except that they’re not, as even a crude measurement is more accurate than a nonexistent one. In other words, I rescind my judgement.

As best I can tell, the answer is this: Find a drinking straw and a bit of clay. Jam the latter into one end of the former. Add water to whatever you’re using as a test jar, then stick the straw clay-end downward in the water. Make sure it floats; if it doesn’t, you’re just measuring how deep the jar is. No one needs to know that. Once it floats, mark where on the straw the waterline is. This mark represents a specific gravity of 1.0. Repeat with common household liquids (various oils, vinegar, milk, chloroform), comparing the markings to this or another such table until you have something which will allow you an educated guess at the density of whatever liquid you were originally intending to measure.

Now, most tutorials recommend using a commercial-made hydrometer to calibrate your straw if you have one available. I…I’m not going to point out the logical fallacy in this. I will say that if you have made a straw and clay hydrometer and happen to have it in your possession while you are also in the presence of a hydrometer which you can use long enough to calibrate a straw but not long enough to actually measure anything with it, then yes, you should do that. Go ahead.