Stupid thread but I'm new

[CapnClunks]

I use a refractometer I took first sample and stupidly read the sg scale and not the Brix. So my 1.045 beer accordingly in Brix is actually 1.07 wtf am I doing wrong. Yes sg is linear but Brix isn't some bs

 

[MHB]

There is a simple equation that is used to switch between S.G. and Brix or Plato (oP) in brewing rather than wine making, it's
SG=(4*oP)/1000+1
You could rearrange the equation to give
oP=(SG-1)*1000/4
Your 1.045 comes to in effect 45/4=11.25oP (or Brix)
You are right Brix/oP isn’t linear. Those equations are linear, but across the brewing range (1.000 to say1.100) the error is probably smaller than you can measure with normal home brewing equipment. The exact relationship is a 3rd order quadratic equation and we really don’t need that sort of accuracy.
Just remember that you can’t use the refractometer once fermentation starts without massaging the numbers. There are plenty of places to convert an apparent Brix/oP to get the right answer.
Mark

 

[philrob]

Doesn't matter much how you read it. For our purposes SG is close enough to 4x Brix.
What result you read will depend whether you read it pre-fermantation, part way through, or at completion.
If at completion, you will need to use some sort of brewing software to make a correction for the alcohol content.
Or, you can use this chart:

Edit: MHB beat me to it.

 

[CapnClunks]

There is a simple equation that is used to switch between S.G. and Brix or Plato (oP) in brewing rather than wine making, it's
SG=(4*oP)/1000+1
You could rearrange the equation to give
oP=(SG-1)*1000/4
Your 1.045 comes to in effect 45/4=11.25oP (or Brix)
You are right Brix/oP isn’t linear. Those equations are linear, but across the brewing range (1.000 to say1.100) the error is probably smaller than you can measure with normal home brewing equipment. The exact relationship is a 3rd order quadratic equation and we really don’t need that sort of accuracy.
Just remember that you can’t use the refractometer once fermentation starts without massaging the numbers. There are plenty of places to convert an apparent Brix/oP to get the right answer.
Mark

According to my readings as a amateur with two packets of Nottingham my today reading at 20.9 is 1.044 my og in reading is 1.045 after 3 days now is I line up on my refractometer ( I have calibrated also with distilled water then wort solution with refractometer is 0.657 correction factor) but if I line up Brix with sg using brewfather it's 11 Brix so roughly og is 1.07 not 1.045 I plug in the numbers my brew is now 1.029 makes more sense after 4 days notty I will hydro tomorrow to test.
Now I know refractometer is for sugars so when fermentation occurs water + alchol so not so great but I have calibrated refractometer and software

 

[CapnClunks]

I'm a

Doesn't matter much how you read it. For our purposes SG is close enough to 4x Brix.
What result you read will depend whether you read it pre-fermantation, part way through, or at completion.
If at completion, you will need to use some sort of brewing software to make a correction for the alcohol content.
Or, you can use this chart:

Edit: MHB beat me to it.

I'm aware of the 4 X approximate but I'm refarering to fermented wort

 

[CapnClunks]

I think my mistake is not measuring of in brix

 

[CapnClunks]

There is a simple equation that is used to switch between S.G. and Brix or Plato (oP) in brewing rather than wine making, it's
SG=(4*oP)/1000+1
You could rearrange the equation to give
oP=(SG-1)*1000/4
Your 1.045 comes to in effect 45/4=11.25oP (or Brix)
You are right Brix/oP isn’t linear. Those equations are linear, but across the brewing range (1.000 to say1.100) the error is probably smaller than you can measure with normal home brewing equipment. The exact relationship is a 3rd order quadratic equation and we really don’t need that sort of accuracy.
Just remember that you can’t use the refractometer once fermentation starts without massaging the numbers. There are plenty of places to convert an apparent Brix/oP to get the right answer.
Mark

So mhb I'm curious is efficiency how much sugar I get out of grain where Brewhouse is how much liquid I get at the right density?

 

[CapnClunks]

So mhb I'm curious is efficiency how much sugar I get out of grain where Brewhouse is how much liquid I get at the right density?

If it's too the third order it's no longer quadratic so x^3 is x^2*X whereas x^4 is quadratic hence (X^2)^2 following standard rules of exponential functions

 

[MashBasher]

Buy a hydrometer. Take a sample. Stop trying to overcomplicate something very simple.

 

[CapnClunks]

Non quadratic equations can be solved using suggestive theorems such as Descartes law of signs etc but they can't be solved as fast as quadratics of form that are even.

 

[CapnClunks]

Buy a hydrometer. Take a sample. Stop trying to overcomplicate something very simple.

May be simple but seems to me more risk of infection while taking said sample

 

[CapnClunks]

Buy a hydrometer. Take a sample. Stop trying to overcomplicate something very simple.

Think of it this way a small pipette vs a cup

 

[CapnClunks]

Buy a hydrometer. Take a sample. Stop trying to overcomplicate something very simple.

I already have a hydrometer so hard to read vs refractometer

 

[MashBasher]

Nope.

A hydrometer is accurate if you degass (twirl it!) and sight it correctly at fermentation temps.

Complex equations are no substitute for practical and pragmatic measurement.

For hundreds of years, every excise agency everywhere in the world has used hydrometers to measure alcohol content. It's a defacto standard.

Save your refractometer for unfermented wort and use it to get your pre- and post-boil gravity. It is useful for determine adjustments to hit OG, if not completely accurate.

We need a variety of tools to get the job done.

And Google the leather pants a brewery inspector was once issued with.

 

[MashBasher]

Also meant to say if you are worried about a cup of beer you are making too small a batch .

 

[CapnClunks]

Nope.

A hydrometer is accurate if you degass (twirl it!) and sight it correctly at fermentation temps.

Complex equations are no substitute for practical and pragmatic measurement.

For hundreds of years, every excise agency everywhere in the world has used hydrometers to measure alcohol content. It's a defacto standard.

Save your refractometer for unfermented wort and use it to get your pre- and post-boil gravity. It is useful for determine adjustments to hit OG, if not completely accurate.

We need a variety of tools to get the job done.

And Google the leather pants a brewery inspector was once issued with.

Yes but does twirling and degassing not sound like a f around I agree refractometer is garbage for fermented wort but still I put three drops vs 150ml minimum larger surface area more chance infection right vs tiny pipette.
But that's not why I use refractometer I use because convince not that I care it's 0.001 out

 

[CapnClunks]

Also meant to say if you are worried about a cup of beer you are making too small a batch .

I make 23 l batches I'm not worried about a cup beer gone missing it's about surface area, everytime I take off the lid I'm clean as possible why would I try to introduce other bacterial agents if I can avoid. Yes my hand is Covered in yeast but not yeast I desire

 

[MashBasher]

sterilise tap>vial>sterilise tap.

DO NOT REMOVE LID.

 

[CapnClunks]

Current Setup

 

[CapnClunks]

sterilise tap>vial>sterilise tap.

DO NOT REMOVE LID.

I don't use taps too high chance infection