Yes but will that work with a refractometer? I am assuming yes because as long as its a consistent reading it should be rightLet your brew ferment for at least 10 days then measure SG. Leave another 2 days and repeat. 9 times out of 10, fermentation is well finished and the 2 readings are the same and you're good to go minus 200mls if beer
... have a read of the notes underneath the Brewers Friend refractometer calculator there (link), I think all that stuff around Brix WRI vs Brix/Plato and calibrating a Wort Correction Factor will be the "faff" being talked about (and what they don't mention in that text about calibrating refractometers is how it's quite common to find you need a different correction factor for dark coloured worts than when measuring lighter worts
) ... and then there's the difficulty of getting a clear reading when there's any sort of turbidity in the wort you're measuring.
I'm guessing"yes". Best way to find out is to check with a hydrometer for a couple of brews to confirm your theory.
With the refractometer?
No. I use the hydrometer that I had left in the brew......
Indeed, my point though is not whether it is inaccurate so far as an actual FG reading is concerned, that can be done with a hydrometer at leisure, my question is whether it can be used to check for end of fermentation, so for instance if I check the Brix for 3 days in a row and the reading remains the same can I reliably say that fermentation has ended? If it has I can do an FG with the hydrometer and then bottle at leisure.
... Yes ... if fermentation was continuing, then there would be less sugar in the sample and the refractometer reading would be lower ... not as low as it would have been if you'd somehow removed sugar without it turning into more alcohol, but still lower ... stable readings over that period means fermentation is finished
Thanks Phil that is exactly what I wanted to hear :)Hi Galena
... Yes ... if fermentation was continuing, then there would be less sugar in the sample and the refractometer reading would be lower ... not as low as it would have been if you'd somehow removed sugar without it turning into more alcohol, but still lower ... stable readings over that period means fermentation is finished
Cheers, PhilB
This confused the hell out of me …
One drop, well that is different I will have to try that. Interesting information thanks and this is kind of how I envisage using mine (when it arrives). I have a tap for drawing off a little so no need to keep opening up the FV. CheersI’m yet to get reliable reading from my refractometer, but I find it is a useful guide. Mine was bought from MM (I think) and was around £35 ish and is supposed to be ATC, but I still have to calibrate it every time with RO water first and this reading does vary, I assume because of room temperature variations.
The refractometers we usually use are designed for wine making (fructose) which is pretty consistant, if we’re using them for beer, the cocktail of different sugars in our wort will vary by recipe and needs that correction factor to work. It does sound like a faff, but if you’re using software like BeerSmith it’s incredibly easy.
I take a hydrometer reading for OG and from this sample also note the refractometer reading, these both get entered for that session and this gives me my refractometer calibration, which it stores for that brew. All subsequent readings simply have the option selected that calculates for alcohol present and it uses the OG already entered as reference.
I take two readings a day until gravity settles down, the sample drawn can be as small as practical, about a tablespoon. I’ve found the clearest reading uses only one single, small drop on the glass, it doesn’t matter how turbid the sample is.
I still use a hydrometer to take the FG from a de-gassed sample taken from the final serving keg so the beer has been fully mixed. I don’t get a reliable FG calculation from the refractometer, but it is a useful indication.
<edit> I take regular samples from a sampling port, I’m not endorsing lifting the lid on a FV several times a day!
Cheers, will certainly give it a try
Alcohol is compensated for by using a calculator (essential if the wort has started fermenting) but the wort compensation factor used by those calculators has to compensate for the difference between a predominantly maltose solution (wort) and the sugar solution native to BRIX (@Edison, I thought that was the disaccharide sucrose not the monosaccharide fructose?). A factor of 1.04 is often used as the default. But as wort ferments that correction factor must change but I've no idea how much the change is relevant?
I'll have to try that too! I've always "guessed" which obviously isn't the best.
I never new that. I wonder how close it would be to take a reading with a hydrometer and a reading with a refractometer and then split the difference without doing any corrections.
Brewing is so entrenched in it's use of "apparent" SG that going with anything else will cause confusion. As does "apparent" and "real" attenuation. You just need to stick with the accepted measures unless some radical change takes place (unlikely).
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