Hydrometer vs Refractometer

[Millerhomebrewer]

In the past I have always used a Hydrometer when making wine, and continued this during my recent introduction to Craft Beer Brewing up until someone turned me on to a Refractometer. This is new and with anything there is growing pains. The problems are with the different readings I'm getting between the 2 measurements. Recently I read about a correction factor for the Refractometer due to the presences of Alcohol. Still this did not solve the problem. The Hydrometer measures my wort now at 1.020 SG the Refractometer measures it at 1.03. If I go by my Hydrometer readings my wort is ready 1.061 OG and 1.020 FG will give my approximately 5.4%. My gut tells me BOTTLE IT! What to do?

 

[MapleGroveAleworks]

What is your expected FG? I trust a calibrated hydrometer post fermentation over refractometer.

Check the gravity over 3 days. If it doesn't change and you're at the FG of your recipe per your hydrometer, then package

 

[PADave]

Go by your hydrometer reading. I liked my refractometer so much that it got delegated to the junk I don't use anymore shelf.

 

[Millerhomebrewer]

What is your expected FG? I trust a calibrated hydrometer post fermentation over refractometer.

Check the gravity over 3 days. If it doesn't change and you're at the FG of your recipe per your hydrometer, then package

1.018 is my expected final so I'm done but I don't think I like the Refractometer meter. I think I'll stay with what has worked for 12 years

 

[Bigfly]

I like the refractometer for checking the gravity of the wort after mashing while hot. Hydrometer is most accurate through the whole process though.

 

[LLBeanJ]

I use my refractometer on brew day only. For that purpose, it's a great tool.

 

[Hwk-I-St8]

I use my refractometer on brew day only. For that purpose, it's a great tool.

This.

 

[jalc6927]

I use my refrac on brew day and to check FG, easier and just as accurate as hydrometer,

 

[Calder]

Like others, I too mostly use the refractometer for checking mash.

I like using the Hydrometer for any checks I do after fermentation. Immediate results (no calculation), less chance of a mistake, and what I really like is that you can also drink the sample. I think I get more information from drinking the sample than from just the reading.

One useful thing you can do with a refractometer, is figure out the OG. If you have a beer that you don't know the OG of, or one that you made some additions to along the way, or maybe trying to disect the gravities of a Commercial beer; if you take both an hydrometer reading and a refractometer reading of the FG, you can use a calculator to determine the OG.

 

[tjmac5071]

I got so frustrated with my refractometer giving different results I stopped measuring anything until it's chilled and in the fermenter and I could use my hydrometer / tilt.

 

[Millerhomebrewer]

Thank you for all the information. I did bottle yesterday and my FG was 1.020, which gives me my ABV of 5.9% a little above my target but I'm happy. 3 weeks and the true test will be done. Luckily most of this time will be spent traveling for business so I won't be tempted. CHEERS

 

[helibrewer]

In the past I have always used a Hydrometer when making wine, and continued this during my recent introduction to Craft Beer Brewing up until someone turned me on to a Refractometer. This is new and with anything there is growing pains. The problems are with the different readings I'm getting between the 2 measurements. Recently I read about a correction factor for the Refractometer due to the presences of Alcohol. Still this did not solve the problem. The Hydrometer measures my wort now at 1.020 SG the Refractometer measures it at 1.03. If I go by my Hydrometer readings my wort is ready 1.061 OG and 1.020 FG will give my approximately 5.4%. My gut tells me BOTTLE IT! What to do?

Remember that even though fermentation might be complete, the yeast aren't really finished. There is clean up of off flavor by-products to be done and several days to a week at terminal gravity allows this to happen...you can elevate the temp a few degrees also to help it along.

 

[Owly055]

I use a refractometer exclusively. My batch size is small and hydrometer testing consumes more wort than I want to sacrifice. I own two hydrometers, but rarely ever use them. I'm completely satisfied with the refractometer for my purposes. There is a lot of variation in the quality of refractometers it seems, and this does not seem to be reflected in price..... In other words, an expensive one is not necessarily any better than a cheap one. Movement in the internal parts is the problem I've seen. Slight changes can result in real problems. It's virtually impossible for a hydrometer to read off if the scale is correct for the weight and buoyancy.
H.W.

 

[aprichman]

In school (fermentation science) it was discussed how every recipe of beer would require a custom conversion for a refractometer.

In lab we measured beer with a hydrometer, refractometer, and densitometer. The refractometer (which was lab grade) was by far the least accurate.

For homebrewers a calibrated hydrometer is your best bet.

 

[Derp]

One useful thing you can do with a refractometer, is figure out the OG. If you have a beer that you don't know the OG of, or one that you made some additions to along the way, or maybe trying to disect the gravities of a Commercial beer; if you take both an hydrometer reading and a refractometer reading of the FG, you can use a calculator to determine the OG.

What's the formula/procedure for doing that?

 

[Calder]

What's the formula/procedure for doing that?

I have no formula for it. I use the refractometer calculator in BeerSmith If you know the final gravity (hydrometer), and final BRIX (refractometer), you can figure out the original BRIX.

It is basically using the same calculator to determine FG when you have n OG and a final BRIX. All you need is 2 of the three variables to calculate the third.

 

[liljohn]

What's the formula/procedure for doing that?

https://www.northernbrewer.com/learn/resources/refractometer-calculator/

I don’t know the formula but here are the calculators.