24 replies to this topic

[SchwanzBrewer]

I'm too impatient to wait for the wort to cool down to see what the OG is on my beers after/during the boil, and too impatient to grab a sample after i'm done chilling because by that time I am about ready to quick and don't care. So, I was thinking about getting a refractometer. I guess then I don't have to sorry about temp for the OG, but if I want to know the FG I gotta do some calulations. Any idea how accurate the calculations are? If they are within a couple points then its no big deal, I'll be sold. Hell I might be sold anyway.Seems like a logical step in order to gain better control over my brews.What do ya'll think?Cheers,Rich

[MakeMeHoppy]

I just can't get mine to give good readings after fermentation vs. the hydrometer. However, on brew day it's one of the best things I've bought. You can usually find one online for about $35 and I just take the reading in brix multiply by 4 and I have a good estimate of the gravity. Of course having accurate volume measures it also important. I like it with all grain because I can get a good idea of how many gravity points are in the kettle. Now all I have to do is monitor my boil off rate and I make my SG every time. If you are way under what you expect you can add some extract while the boil is still on. If you are way over you can dilute or maybe add more hops to compensate.

[djinkc]

There are some some calculators out there that will let you read a FG with a refractometer. You must have an OG though. I have not tried this one but it looks like you could plug it into an Excel SS assuming it will handle that many digits right of the decimal point. It took forever to load this page but here it is.https://seanterrill....er-correlation/

[weave]

Why not just use your hydro for post-ferm gravity readings and use the refracto for pre-ferm gravity readings. Then you don't need to be concerned about conversion of values of your post-ferm readings. That's what I do. On brew day I get real time gravity readings with the refracto and once ferm is underway and temp (and time) isn't so much of an issue I use the hydro.

[ncbeerbrewer]

Why not just use your hydro for post-ferm gravity readings and use the refracto for pre-ferm gravity readings. Then you don't need to be concerned about conversion of values of your post-ferm readings. That's what I do. On brew day I get real time gravity readings with the refracto and once ferm is underway and temp (and time) isn't so much of an issue I use the hydro.

+1 I got a refracto back in 2008. One of the best brewing tools I bought. You won't go wrong with it Rich!Mike

[shaggaroo]

There are some some calculators out there that will let you read a FG with a refractometer. You must have an OG though. I have not tried this one but it looks like you could plug it into an Excel SS assuming it will handle that many digits right of the decimal point. It took forever to load this page but here it is.https://seanterrill....er-correlation/

I've used this. Works very well.

[denny]

There's been a big discussion on the AHA forum about using one post ferment. People have been experimenting with the different correction formulas and it looks like none of them are very close. The best one is an experimental one that isn't readily available and it's 3-4 points off. I've had a refractometer for a long time but I gave up on using it because it started deviating from my hydrometer so badly. These days I pull a 6-8 oz. sample from the kettle with a Pryrex measuring cup and pour it in a metal cocktail shaker. I put that in a bowl of ice water and swirl it around. In 2-3 min. it's down to 60F and ready to measure.

[SchwanzBrewer]

They have them now that read in specific gravity instead of brix. I guess my worry is about how accurate they are. Do you have to calibrate it? If so, how do you accurately calibrate it?Cheers,Rich

[ncbeerbrewer]

They have them now that read in specific gravity instead of brix. I guess my worry is about how accurate they are. Do you have to calibrate it? If so, how do you accurately calibrate it?Cheers,Rich

I have not seen any Refract that reads in specific gravity, mine reads in Brix. You multiply the Brix by 4 and add 1.0 to get your Specific Gravity therefore 12 Brix x 4 is 1.048.To calibrate I just use tap water and dial in the small screw on the refracto so that its "zeroed out" If you look it up they say use distilled water which yes is best too. I always take a final post boil SG reading with my refracto then start my chilldown. Then when I get the wort down to 80 I take a hydrometer sample chill to 60 degrees and take my "official" SG reading. My refracto and hydrometer reading matches each time. Its pretty simple

[SchwanzBrewer]

I have not seen any Refract that reads in specific gravity, mine reads in Brix. You multiply the Brix by 4 and add 1.0 to get your Specific Gravity therefore 12 Brix x 4 is 1.048.To calibrate I just use tap water and dial in the small screw on the refracto so that its "zeroed out" If you look it up they say use distilled water which yes is best too. I always take a final post boil SG reading with my refracto then start my chilldown. Then when I get the wort down to 80 I take a hydrometer sample chill to 60 degrees and take my "official" SG reading. My refracto and hydrometer reading matches each time. Its pretty simple

specific gravity and brix refractometerthanks for the info!

[zymot]

I use my refractometer as a tool convenience because it requires a small sample. It gives me an idea what is going on with my beer.For unfermented wort, the refractometer I have is very close to my glass hydrometer. The difference is within the tolerence of the interpretation of where the line is.For wort that is fermenting, I have seen a few different formulas to convert the refractometer reading to actual OG. The couple times I compared to a glass hydrometer, it was pretty close.When it comes to fermenting wort, I do not get all wound up on actual measured values. By the time my beer is finishing up, who cares if it is 1.008, 1.012, 1.016? Not much I can do about it. I made the wort, pitched the yeast and let it age. It is going to turn out how it is going to turn out.I can easily pull a OG sample and a tastes sample. Few drops of on the refractor, an ounce or so in zymot. Done."Oh my beer is at 1.012, it is supposed to be be 1.008!" I am more likely to create a problem by trying to squeeze it down to 1.008 than just letting it finish up how it is wants to finish.I use the refractomter as a delta tool. Instead of the literal measured value, I look for when the reading has stopped changing. No change for a few days, a week, whatever, the beer is done. Then I run the value through a calculator to see what the FG is.

[BlKtRe]

Why not just use your hydro for post-ferm gravity readings and use the refracto for pre-ferm gravity readings. Then you don't need to be concerned about conversion of values of your post-ferm readings. That's what I do. On brew day I get real time gravity readings with the refracto and once ferm is underway and temp (and time) isn't so much of an issue I use the hydro.

This. Plus I always want to taste. Tasting your OG and FG samples along the way will give you alot of information. I couldn't imagine not knowing what my wort/beer tastes like.Also, I couldn't imagine NOT brewing without my Refracto. One of the best tools in the brewery.

Edited by BlKtRe, 31 March 2011 - 05:52 AM.

[BarelyBrews]

We use a digital reader at work, the hand-held was a pain the butt.Its been sitting in the lab for around 4 years,No-one uses it.For accuracy i prefer my hydrometer.

[weave]

This. Plus I always want to taste. Tasting your OG and FG samples along the way will give you alot of information. I couldn't imagine not knowing what my wort/beer tastes like.Also, I couldn't imagine NOT brewing without my Refracto. One of the best tools in the brewery.

Good point. I do like to taste my wort pre-boil and post boil. Refracto sized samples don't really allow for that. The refracto is a tool I use to get real time wort gravity measurements so I can adjust on the fly. The biggest benefit I get from using a refracto is the ability to precisely control specific gravity. I sparge to collect a SG in the kettle, not to collect a given volume. No way I could do this if I had to wait for a sample to cool and use a hydro.

[BlKtRe]

I sparge to collect a SG in the kettle, not to collect a given volume. No way I could do this if I had to wait for a sample to cool and use a hydro.

Another excellent point. Preboil OG is important in my game. I pride myself in balanced beers and the refracto is a very useful tool in making this tons easier. Let alone double checking the sugars left in the MT towards the end of a fly sparge. Quick and easy!

[ChicagoWaterGuy]

My refractometer reads in brix down to 0 and gravity down to about 1.020 (not exactly sure, it isn't in front of me).I have found the more beer spreadsheet to adjust fg very acurate when comparing to a hydrometer reading. The key is to be as precise with the brix reading as possible.

[zymot]

My refractometer reads in brix down to 0 and gravity down to about 1.020 (not exactly sure, it isn't in front of me).

Something does not make sense.0 brix = 1.000~5.00 brix = 1.020

[ChicagoWaterGuy]

Something does not make sense.0 brix = 1.000~5.00 brix = 1.020

It makes sense, the brix side goes to 0, the gravity side stops at 1.020. I didn't say those lines were equal. Two scales on opposite sides of the view window.

[zymot]

It makes sense, the brix side goes to 0, the gravity side stops at 1.020. I didn't say those lines were equal. Two scales on opposite sides of the view window.

Interesting. I would be curious to see what the display looks like.