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Hughbedo

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Though I expect to stay. I bought one of these refractive hydrometers. It has a scale from 0 - 80% alcohol v/v, my pre-fermentation mix measures at 55%. Is there a way to convert this reading to a density measure that can be used for brewing?

I have started brewing to get me through the lockdown, but in a very ad hoc way. I have been brewing water and sugar in a large saucepan, and transferring it to used sparkling water bottles. I have done a few batches of ginger beer, and now the season is just starting I have made one of elderflower champagne roughly following this recipe. I really want to use the hydrometer to work out when the 1st stage fermentation has finished. Thanks in advance for any help.
 
"Refractive hydrometer"? Well that should cause plenty of confusion! Have you a Refractometer or a hydrometer? If the former (microscope-like thingy you look through) you should be looking for a BRIX scale (and be asking what can be done with that) and if the latter (fishing float like thingy that … well, floats) look for the SG scale. Any other scales are just eye candy and can be ignored.
 
If you've got any more questions it might be a good idea to ask them in the thread title.
 
> If you've got any more questions it might be a good idea to ask them in the thread title.

I started in the Introduce Yourself forum, and thought it an appropriate title for that, when it was moved I could not figure out how to change it.

> Have you a Refractometer or a hydrometer?

It is a Refractometer. I thought as it was measuring density it was also a hydrometer, but I guess I was wrong.

> if that's the version you bought with the v/v scale, I fear you have bought the wrong one

Doh. So there is no way to convert the reading? I guess I can wait until the reading does not change from one day to the next, and then fermentation has finished?

> Whats up with a hydrometer? Cheap and cheerful, does the job, and can be used by mostly everyone without needing a manual.

I think you may be right. I decided on this so I could do the test with only a few drops, rather than having to fill a vessel deep enough to float a hydrometer in, and it was only a bit more expensive than the hydrometers I found online. However if it does not do the job I will have to get a hydrometer.
 
If you’re just starting out, you may find a hydrometer easier to use. I have only recently bought a refractometer and managed to get hold of one which is 0-20 brix. This is slightly easier to read due to the larger scale
 
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> Whats up with a hydrometer? Cheap and cheerful, does the job, and can be used by mostly everyone without needing a manual.

I think you may be right. I decided on this so I could do the test with only a few drops, rather than having to fill a vessel deep enough to float a hydrometer in, and it was only a bit more expensive than the hydrometers I found online. However if it does not do the job I will have to get a hydrometer.
Lower your sanitised hydrometer into your brew in the FV, that's what I do to take SG readings, twice. First to take the OG before I pitch the yeast, then the FG at packaging time when its done. Simple, and good enough for me.
 
If you’re just starting out, you may find a hydrometer easier to use. I have only recently bought a refractometer and managed to get hold of one which is 0-20 brix. This is slightly easier to read due to the larger scale
Careful how you use your refractometer. They're ok to use on wort but once there's alcohol in the mix you'll have to apply correction. There's a tool on this site.
 
I looked at the calculators, particularly this one, but could not find somewhere to convert 55% to something I could use.

When I started, 4 days ago, it was 55%, today it was 46% and still tastes quite sweet. My current plan is to fall back on the sugar concentration meter I was born with, and stop when it no longer tastes sweet.
 
I think, as said above, you’ve bought the wrong instrument. asad1.
9B219311-29AE-4803-93F7-A3762CA9DFC7.jpeg

The product description describes it for use with distillates WITHOUT sugar. Fermenting wort has sugar. The scale is therefore irrelevant. I have a similar instrument that I use for checking SG of the wort during mashing. Once alcohol is involved, it’s best (IMHO) to revert to a hydrometer. I actually measure the OG with my hydrometer once the mash and boil is complete.
 
I thought that although I bought the wrong thing, if my mix was reading on that scale it must be convertible. However it seems like alcohol and sugar change the density of water in opposite ways, so how am I getting any reading at all? I do not understand. I guess I do not need to, I shall just have to get a floaty one. Does everyone else dunk it in the fermentation vessel? I was worried about contamination.
ethanol-water-mixture-density.jpg
350px-DensityVsSucrose2.PNG
 
I thought that although I bought the wrong thing, if my mix was reading on that scale it must be convertible. However it seems like alcohol and sugar change the density of water in opposite ways, so how am I getting any reading at all? I do not understand. I guess I do not need to, I shall just have to get a floaty one. Does everyone else dunk it in the fermentation vessel? I was worried about contamination.
ethanol-water-mixture-density.jpg
350px-DensityVsSucrose2.PNG

Look, you didn't by something unusable (don't listen too much to the old farts), in fact it's great for smaller batches where hydrometer tests take a lot of brew away. And refractometers also work with hot wort, so in the early parts of brewing.
But hydrometers are more fun, that's for sure, and they can be dunked into the brew, after they're sanitised of course.

Refractometers require a bit more thinking, that's all. But they work.
 
I thought that although I bought the wrong thing, if my mix was reading on that scale it must be convertible. However it seems like alcohol and sugar change the density of water in opposite ways, so how am I getting any reading at all? I do not understand. I guess I do not need to, I shall just have to get a floaty one. Does everyone else dunk it in the fermentation vessel? I was worried about contamination.
ethanol-water-mixture-density.jpg
350px-DensityVsSucrose2.PNG
So, you can still use your gizmo but you need to calibrate it (as I did with mine even though it had a SG scale). When you get your hydrometer, start with distilled water as your starting point (SG 1) and see what it reads with your refractometer and hydrometer. Make a note. Dissolve some sugar into the water and repeat readings. Plot a graph (excel?) so you can convert your refractometer reading to SG, but only for wort. Not for beer.
 

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