Beer Not Fermenting All The Way - Final Gravity 1025 - 1030?

[Wolfy]

So what is the most accurate way of measuring gravity? Hydrometer or refractometer? I originally got the refractometer as it seemed like the more accurate option. However it seems there is some room for error when adjusting for alcohol for the refractometer. Thoughts?

Accuracy for unfermented wort should be the same as the hydro, however - as others have said previously - once there is alcohol in the sample the refractometer's reading gets distorted and needs to be corrected via a calculation/spreadsheet/graph, so in those cases the hydrometer will be more accurate (very much so if the reading is not corrected - as you have found out).
Personally I don't get too stressed about exactly what the FG readings are, if I know the yeast has finished it's work, if the beer is close to the expected FG and it tastes fine, then whatever the exact numbers are are not that important. Hence I find that my refractometer is more than accurate enough and it's quick and easy to use, which makes up for it possibly being slightly less accurate.

 

[argon]

I use the refrac during brewing to see what first runnings are, pre-boil and then post boil to see how much water i need to add (can't do full boil). Then once cool and ready to pitch I use hydro, samples during ferment and at end all hydro. Can't be bothered with conversion tables.

Couldn't be bothered?? You must be lazier than me... And that's a big call. I keep a print of the conversion chart on the side of the fermenting fridge. Take a tiny refrac sample then look at the chart for the correct number. On top of the fermentor I write the beer style and the OG so I know what to look for upon conversion. Simple and I find it easier than collecting enough wort for a hydro. Since I got the refrac, I've not used the hydro. Love it.

 

[bignath]

This:

Accuracy for unfermented wort should be the same as the hydro, however - as others have said previously - once there is alcohol in the sample the refractometer's reading gets distorted and needs to be corrected via a calculation/spreadsheet/graph, so in those cases the hydrometer will be more accurate (very much so if the reading is not corrected - as you have found out).
Personally I don't get too stressed about exactly what the FG readings are, if I know the yeast has finished it's work, if the beer is close to the expected FG and it tastes fine, then whatever the exact numbers are are not that important. Hence I find that my refractometer is more than accurate enough and it's quick and easy to use, which makes up for it possibly being slightly less accurate.

and more of this:

Couldn't be bothered?? You must be lazier than me... And that's a big call. I keep a print of the conversion chart on the side of the fermenting fridge. Take a tiny refrac sample then look at the chart for the correct number. On top of the fermentor I write the beer style and the OG so I know what to look for upon conversion. Simple and I find it easier than collecting enough wort for a hydro. Since I got the refrac, I've not used the hydro. Love it.

I love my refractometer. I gave my hydrometer to a friend and haven't missed it one bit. Love the small samples, and the ability to take instant gravity readings at any stage of the beery process..

For me, i find them both accurate (assuming correct conversion with refractometer of course).

I stick a note pad page on each fermenter with the details of the beer fermenting, it's OG so i know what column on my conversion chart to use. Too easy...

I've also laminated my chart so it can be next to me when i'm brewing with no risk of it being destroyed by liquid spillage.

I'll never use a hydrometer again.

 

[cdbrown]

Couldn't be bothered?? You must be lazier than me... And that's a big call. I keep a print of the conversion chart on the side of the fermenting fridge. Take a tiny refrac sample then look at the chart for the correct number. On top of the fermentor I write the beer style and the OG so I know what to look for upon conversion. Simple and I find it easier than collecting enough wort for a hydro. Since I got the refrac, I've not used the hydro. Love it.

For me it's a lot easier to take hydro readings - need to get the samples from the tap anyway as there's not enough room above the fermenter to get a sample from the top. Also find it helpful to taste the brew as it's fermenting to see how the characteristics change.

 

[drsmurto]

For me it's a lot easier to take hydro readings - need to get the samples from the tap anyway as there's not enough room above the fermenter to get a sample from the top. Also find it helpful to taste the brew as it's fermenting to see how the characteristics change.

Agree with this and will add i find it much harder to get 1 drop out of a fermenter tap than simply open the tap and get 100mL for the hydrometer.

Tasting and smelling as the wort is transformed to beer for me is part of the brewing process. I learn a lot from this and am able to use that knowledge when repeating a beer knowing what it will smell and taste like at any point.

I do use a refractometer on brewday but when after the pre-boil reading i use a hydro for the rest of the 'beers' life.

 

[hsb]

Love drinking those Hydro samples :chug:
Sometimes gets a bit annoying when you've got a dawdler that sits at 1016, maybe just moves to 1015, could it be at 1014 yet... hydro would be nice for those ones but by and large agree about hydro samples, get to see the beer clarity too and get a better 'nose' of it.

 

[bignath]

Agree with this and will add i find it much harder to get 1 drop out of a fermenter tap than simply open the tap and get 100mL for the hydrometer.

I have a cough medicing measuring cup, you know the ones... The clear little cups that have meaurements up to about 15ml on them. I use that as my sample collecting container, take my three drops out of that for refract reading, and then drink the rest. It's enough on the pallette to get an idea of the beers flavour and progress, and still haven't had to take much beer out of the container.

Works well..

 

[Brad Churchill]

I love the ease of the refractometer.
Also because I brew small batches (14 litres mostly) I don't like to reduce the amount of beer I will have left.
I do like to taste it though as others have said so I draw off about 30 ml or so in a glass and taste it that way.
Bottling day is always done with a hydro sample though which I sip away at as I bottle and try to imagine what it will taste like once conditioned.

Cheers
BC

Yeah much as Big Nath does. The way to go IMO.

 

[philski]

Ok so here are the results from the latest brew. I'm still a little confused with the variation bw the refractometer and hydrometer after conversion....

I've taken it out of secondary and kegged the latest brew and I took several measurements.

The hydrometer reads 1015. The refractometer reads 1025 or 6.3% brix.

So doing the conversion I get the following results:

From the calculator here http://brew.stderr.net/refractometer.html

If I plug in the OG of 1.047 and the final brix of 6.3%, into the calculator here http://brew.stderr.net/refractometer.html it says the FG is 1.011 and it's 4.8%. From the graph previously mentioned in this forum I get the same result (as it's based on the formula from the website). So that makes sense.

From Beersmith

If I use the refractometer tool in beersmith I get a similar result to the above. Under the "fermenting wort gravity section" If I enter an OG of 1.047 and a brix of 6.3% it gives me 1011 and says its 4.65%. Presumably this is calculated using the "brix correction factor" in the calibration settings - which I am yet to verify.

Then if I use the finished beer section and enter 6.3% brix and my hydrometer reading of 1015 it says my OG is 1041 which is way off 1047.

What doesn't make sense to me is that the hydrometer is reading 1015. I've checked it several times and keep coming up with the same result. Why is there a variation of 4 points bw the adjusted refractometer and the hydrometer? And which is more accurate?

Could my hydrometer be off? Water does read 1000 so I can't see this being the case.

Thoughts? :huh: :huh: :huh:

 

[Wolfy]

Thoughts? :huh: :huh: :huh:

You're getting too stuck up on numbers that are not really important ... if the beer is fully fermented and tastes good, who really cares what any numbers say:

Personally I don't get too stressed about exactly what the FG readings are, if I know the yeast has finished it's work, if the beer is close to the expected FG and it tastes fine, then whatever the exact numbers are are not that important. Hence I find that my refractometer is more than accurate enough and it's quick and easy to use, which makes up for it possibly being slightly less accurate.

 

[philski]

You're getting too stuck up on numbers that are not really important ... if the beer is fully fermented and tastes good, who really cares what any numbers say:

Fair enough, and the beer does taste bloody good when tasting the hydro sample!! It should be a brilliant pale ale!

Either way I'm, still intrigued about the difference. I will take some more samples for the next brew to have something to compare to.

I like to understand the science as well as the art!