Please Help: Using a Refractometer

[goudaphunk]

Hey,

I just purchased my first refractometer and was wondering when I should be using this in the brew process.

I understand that I could use it to take my OG, but at what other times should I be using it? Any help would be greatly appreciated.

Jimmy

 

[kevinb]

You can use it for your FG as well. However, you need to use a formula to correct the reading. I guess the alcohol causes an error in the reading. If you Google it there are lots of resources for the formula. I personally set up an Excel template to do it. If you make starters, this is the best way to check SG and FG since you don't want to use half your starter to fill a tube to float a hydrometer

 

[ThreeSheetsBrewing]

I like it strictly for pre and post boil gravity readings. I assume the small drop has come to room temp and I dont need to do a calculation to compensate for temp. This saves me time and effort during what I find to be the busiest part of the brewing process (making sure I have the correct gravity and making a correction with DME if needed).


Alcohol will skew your results once fermentation starts, and you'll need to do a calculation to get an accurate gravity reading. I'm comfortanle using a hydrometer for FG readings.

 

[b-boy]

I use mine for OG and FG. I also take readings of my first runnings after the mash and the pre-boil wort gravity. It helps me figure out what went wrong during a re-brew of the same beer.

 

[davekippen]

I use mine for OG and FG. I also take readings of my first runnings after the mash and the pre-boil wort gravity. It helps me figure out what went wrong during a re-brew of the same beer.

Yup. All of this!

 

[goudaphunk]

If my OG Is off, how much DME do I add? Is there a formula for that?

 

[ThreeSheetsBrewing]

I use 36 points per gallon (1.036) for DME. Or, 9 points per 5 gallons. (1.009)

 

[Acidjazz54]

I use 36 points per gallon (1.036) for DME. Or, 9 points per 5 gallons. (1.009)

Threesheets, can you explain this a little better? I'm confused.

So say I'm brewing a 5 gallon batch with an estimated S.G. of 1.056 and I measure 1.047 at flameout then I would add 1 pound of DME to bring it up to where I want to be?

If that's correct, do you keep boiling for another 15 minutes or so to "sterilize"?

 

[ThreeSheetsBrewing]

You have the math correct on that. If I need to add DME I will add it to the begining of the boil.

 

[ThreeSheetsBrewing]

To expand on that a little further, I take a gravity reading once I have finished sparging and mash out. Knowing my current volume and gravity and my desired post boil volume I'll calculate my post boil gravity using a phone app called Brewer's Friend. It has a boil off calculation. It also has a brix/S.G. converter I find helpful.

 

[Acidjazz54]

Thanks I understand it now. I also have brewer's friend so I'll have to check that out. I also need to take time and determine my boil off/losses but that's a different issue all together.

Thanks again.