just received my 1st refractometer......does it have to be calibrated?

[Elysium]

I have just received my refractrometer but on the website it said "doesnt need to be calibrated", but there is a manual in the box...saying it does have to be calibrated.

I guess I have no options but calibrate it.....but I have 2 questions.

1, is simple bottled water ok to calibrate it? I dont even know where I could get distilled water from.
2, my room temperature is slightly below 20 C (68F).....is that an issue? Since water has no sugars this shouldnt cause a problem at calibration, right?

Thanks

 

[rklinck]

I generally check with normal water because I figure that is close enough. You can get distiller water at just about any grocery store.

 

[Gitmoe]

Boil some water in a pot with a lid. The water droplets that condense on the lid are distilled water. Harvest a few drop with the dropper that probably came with the refractometer. Let the water cool to room temperature... calibrate.

 

[DrWill]

Rklinck has already answered the first part. Re: temperature, that shouldn't matter. One of the great advantages of refractometers over hydrometers is that you don't need to adjust for temperature.

 

[ajf]

You should be able to get distilled water from a large supermarket (Carrefour, Hipercor etc.) or from a local pharmacy.
I've never had to calibrate mine. I do check it occasionally, but it's never needed adjusting. I've checked it with distilled water and tap water. They both gave the same reading.
As for the temperature, does the refractometer have ATC? If so, then the temperature should not be an issue. If it doesn't have ATC, you will need to adjust for temperature.

-a.

 

[DrWill]

You should be able to get distilled water from a large supermarket (Carrefour, Hipercor etc.) or from a local pharmacy.
I've never had to calibrate mine. I do check it occasionally, but it's never needed adjusting. I've checked it with distilled water and tap water. They both gave the same reading.
As for the temperature, does the refractometer have ATC? If so, then the temperature should not be an issue. If it doesn't have ATC, you will need to adjust for temperature.

-a.

Good call. I was assuming it has ATC.

 

[william_shakes_beer]

Also, the refractometer is only useful on brew day, before you pitch your yeast. Once there is alcohol present, The refractometer does not give accurate readings.


Which leads me to my own question which I just thought of:

If I wanted to use my refractometer post fermentation, would I be accurate if I were to remove a 1.5 oz sample and heat it in the microwave to drive off the alcohol? I'm thinking 20 seconds or so....

I like the small sample size using a refractometer, and the fact that I can withdraw a sample through the arilock hole without removing the bucket lid.

 

[DrWill]

Also, the refractometEr is only useful on brew day, before you pitch your yeast. Once there is alcohol present, tHe refractometer does not give accurate readings.

It is also useful at the end of fermentation. If you forget to note your original gravity, you can calculate it by looking at the difference between a hydrometer and a refractometer reading.

 

[william_shakes_beer]

It is also useful at the end of fermentation. If you forget to note your original gravity, you can calculate it by looking at the difference between a hydrometer and a refractometer reading.

What? How do you do that?

 

[DrWill]

What? How do you do that?

Take both a brix measurement with your refractometer and a gravity measurement with your hydrometer of finished but not carbonated beer. This website or good brewing software will do the calculations for you:

http://www.northernbrewer.com/refractometer-calculator/

If you use BeerSmith I think the calculator can be found under the Refractometer tab under Tools, but I'm not 100% sure. I can check if you want.

 

[IvanTheTerribrew]

When you want to calibrate your refractometer you'll want to use the water you're going to brew with (liquor) because if there is a difference between your water and distilled water, then it will be a bit off for your brew because you aren't using distilled water to brew.

It's a good time to calibrate your hydrometer too. Simply take a gravity reading with the same water at about 68* and see if it's at 1.000 if not, then just note the offset. Cheers

 

[Yooper]

after you calibrate the refractometer, make sure you compare it with your hydrometer in wort and figure your "wort correction factor".

Here's some info on that: http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/

 

[FlyDoctor]

I have an ATC refractometer, but I find that at the end of the boil I get a different reading each time I use it. What I mean is that I will measure a few drops or wort - get one reading, then repeat and get an entirely different reading - often 10 gravity points off of the first. I'm not sure why this happens but it severely limits the utility for me. Perhaps hop matter contamination?

 

[DrWill]

I have an ATC refractometer, but I find that at the end of the boil I get a different reading each time I use it. What I mean is that I will measure a few drops or wort - get one reading, then repeat and get an entirely different reading - often 10 gravity points off of the first. I'm not sure why this happens but it severely limits the utility for me. Perhaps hop matter contamination?

You want to make sure of a few things:

No bubbles. Make sure you have a smooth "sheet" of liquid on the glass

No particulates. Like you said, hop matter will throw readings off.

Temperature. Even with ATC, I find I get more consistent readings if I give it about a minute to cool.

Calibration. As Yooper and others have pointed out, make sure you're calibrated properly, but that's another issue from the one you've pointed out.

 

[FlyDoctor]

Thanks Dr Will! Good advise

 

[Orthobrewsky]

after you calibrate the refractometer, make sure you compare it with your hydrometer in wort and figure your "wort correction factor".

Here's some info on that: http://www.brewersfriend.com/how-to-determine-your-refractometers-wort-correction-factor/

Yes, you need to do that. If you get your correction factor very precise, it will work very well for you. Whatever it is, you should continue to check it against a hydrometer for a while and make minor adjustments to the correction factor until the two readings cease to differ.

I have ATC. It doesn't mean what you might think. It means you don't have to take the reading and use a chart or software tool to get the real value. It does mean you have to calibrate it right before you use it every time, unless your temperature is the same as the last time you calibrated it. Your calibration "automatically" adjusts it for the temperature so that you don't have to take your reading and use something to convert it. It isn't a chore to calibrate. Just put some water on there, hold it to the light, and use your little screwdriver to make the reading zero. Then wipe off the water and use it on a drop of wort or beer.

To calibrate, it makes sense to use the same kind of water you use for brewing. This way it will read zero before any extract comes into the water and will read your concentration of extract after there is some there. However, as someone else confirmed, there is likely to be no detectable difference in calibration whether you use your brewing water or distilled.

As for reading the gravity of fermenting wort, I have found it works very well for this, provided you use a good software tool, such as the one in Beersmith. There is also such a tool online in other places. With the Beersmith tool, I have checked it against a hydrometer reading many times and hardly ever have any difference between the two. When I do, the readings are likely to still be very close such as 1.057 and 1.058.

 

[Orthobrewsky]

Additionally, when using it for fermented beer, you have to input your original gravity into the software tool. I have found that, if your OG readings differed a bit between hydrometer and refractometer, inputting the OG you got from your refractometer will give you a more accurate computation of final gravity.

Of course, if the two OG readings were different, it is probably an indication you need to adjust your correction factor a little.

I will use the wort remaining in my kettle from transfer to take a hydrometer reading and try the same sample with the refractometer. Now that I have refined my correction factor, these rarely differ. When they do, it is probably on a high gravity beer. Even with a well refined correction factor, you may still get a minor difference occasionally because your different styles of beer have different stuff in them which can affect the reading. If you find these occasional differences are as often above the hydrometer reading as below it, you have a good correction factor.

Less frequently, but still rather often, I will take a hydrometer reading on fermented beer, usually when I have a bit extra after filling my keg. Using the software tool, it is very rare for me to have a difference of even one gravity point between the two devices.

The refractometer is a wonderful thing, since it needs only a few drops. Like I said, my refractometer and hydrometer are rarely even one gravity point off. When they are, I don't think it makes much sense for me to care about such a small difference.

 

[stpug]

This thread is enough to scare someone out of using a refractometer

If distilled water reads 0 Brix on your refract then you're calibrated. Droplets on the pot lid previously mentioned are perfect for checking.

Post fermentation readings simply need to be adjusted using an online calculator (or beersmith's refractometer calculator works best for me).

 

[Elysium]

I have an ATC refractometer, but I find that at the end of the boil I get a different reading each time I use it. What I mean is that I will measure a few drops or wort - get one reading, then repeat and get an entirely different reading - often 10 gravity points off of the first. I'm not sure why this happens but it severely limits the utility for me. Perhaps hop matter contamination?

It does say in the manual to wait once you have wort on the prism...at least 30 seconds. It needs to cool down. I havent used mine yet....but I surely wont drop hot wort on the prism. I will put the pipette in a glass of cold water and wait a minute or so and then use it.

 

[IL1kebeer]

I have an ATC refractometer, but I find that at the end of the boil I get a different reading each time I use it. What I mean is that I will measure a few drops or wort - get one reading, then repeat and get an entirely different reading - often 10 gravity points off of the first. I'm not sure why this happens but it severely limits the utility for me. Perhaps hop matter contamination?

If you let the wort sit after its done boiling it will stratify, meaning that the mixture wont be even throughout. This will throw off l your readings because you might be getting different wort compositions in each sample

I bet if you take a reading right before flame out and then wait 30 mins, give it a really good stir, and take another reading, then your readings should be the same. At least they were for me when I tested this for a few batches.

I tend to use my flameout readings as they proved accurate to me tested vs a hydrometer.