refractometer

[walker111]

Hi fellow brewers.
been using the hydrometer for the past 2 years and works fine.......................broke a few!!!!

Thinking about buying a refractometer and was wondering if many of you use one?
Also, can the refractometer give the gravity reading even when my wort is hot? I test SG when I chill my wort around 75. Would like to test when hot and throughout the brew day.
I know there are ways to do this with the hydrometer and adjust but think the refractometer may be an easy fix.
Thanks

 

[IslandLizard]

Refractometers are great tools. They only need one drop to get a reading and it's fast.

• If you put a drop of boiling wort on the prism, it will cool down really fast. BUT... half of the water may have evaporated while transferring it, so your reading comes in falsely, way too high.
• So best is to have it cooled down a bit so it's closer to room temps. The ATC function will compensate for slight temp differences.
• If you take a reading of a liquid (beer) with alcohol in it, it's heavily skewed, reading much too high. You can use a correction formula, or better yet, take a hydrometer reading, instead, which is much more accurate then.
• On most refractometers the SG scale is a little "off," the higher the gravity. The Brix scale is usually accurate.
• It's not worth spending $100-300 on a "lab quality" instrument. A $20-25 refractometer is fine for daily homebrewer use.

So... there's a purpose for both. And you still need a hydrometer.

 

[triletter]

I just use a refractometer for pre and post fermentation. I use a calculating/correction tool for post-fermentation readings. A couple of readings that are the same tells me it's finished without having to draw multiple large samples. I'm pretty confident that I'm within a couple of points of using a hydrometer and, since I don't have to worry about the taxes on the alcohol, a couple of points don't make any difference. YMMV

 

[walker111]

thanks fellas

 

[IslandLizard]

I just use a refractometer for pre and post fermentation. I use a calculating/correction tool for post-fermentation readings. A couple of readings that are the same tells me it's finished without having to draw multiple large samples. I'm pretty confident that I'm within a couple of points of using a hydrometer and, since I don't have to worry about the taxes on the alcohol, a couple of points don't make any difference. YMMV

Yeah, taking those drop sized samples during fermentation, to see where it is, beat any other method. You don't have to lift the lid, just stick a skinny tube or even a long thermometer stem down the airlock hole, and pull out a drop. Keep a notepad with those reading to see a trend. Corrected for alcohol content or not.

 

[wepeeler]

For $14.44, best purchase I've made since switching to All Grain. It sells for $60 elsewhere online! https://www.ebay.com/itm/0-32-Brix-...412079&hash=item2cc7cc075e:g:7awAAOSwtJZXW4YM

So far, it's been perfectly accurate. No need to cool down pre or post boil samples!

 

[SEndorf]

For those of us with poor eyesight, the digital version is fantastic...but a bit pricy.

 

[Saunassa]

For $14.44, best purchase I've made since switching to All Grain. It sells for $60 elsewhere online!
So far, it's been perfectly accurate. No need to cool down pre or post boil samples!

I had thought about one because quick and easy to keep track of pre and post fermentation but not willing to pay 65. Excellent, just ordered one for myself.

 

[Saunassa]

Got it in, wow what a fast and easy way to see if the fermentation was done or not. I was able to see that fermentation was done without having to use large samples of beer.

 

[dmtaylor]

Hi fellow brewers.
been using the hydrometer for the past 2 years and works fine.......................broke a few!!!!

Thinking about buying a refractometer and was wondering if many of you use one?
Also, can the refractometer give the gravity reading even when my wort is hot? I test SG when I chill my wort around 75. Would like to test when hot and throughout the brew day.
I know there are ways to do this with the hydrometer and adjust but think the refractometer may be an easy fix.
Thanks

I love my refractometer, but it doesn't work very well when hot. I still chill my hot samples in the fridge for at least 5 minutes before measuring.

 

[IslandLizard]

I love my refractometer, but it doesn't work very well when hot. I still chill my hot samples in the fridge for at least 5 minutes before measuring.

Put 1/2 oz sample in a heavy shot glass or stainless cup from the freezer. Cools instantly.

 

[El Nino]

I use one and it's pretty spot on from my experience. I haven't looked back, and I like the idea of taking a few drops worth of samples rather than 4 oz every time, especially if you brew batches smaller than 5gal

 

[balrog]

Interesting note on reading hot samples with refractometer
After mashing I put kettle on and light the propane while BIAB drips. By the time I hit boil 12-15min later, I add the drips. Now, during that time I take Refractometer readings to see where my preboil is.

The interesting thing is that as the kettle heats to boil, the readings continue to climb. I have to take 2-3 readings quickly and they'll be similar, but within 5-8min they will start to climb. Whether due to ATC not being too "A"-y, or the @IslandLizard 's evaporative issue, I don't know. Just thought I'd share.

 

[dmtaylor]

Put 1/2 oz sample in a heavy shot glass or stainless cup from the freezer. Cools instantly.

Wouldn't that affect the Brix or OG reading due to freezing and/or condensation from the atmosphere? Frosty mug thang? I hate it when a restaurant or bar pours my beverage into a frosty mug and there's chunks of ice in it. Then if that happens with your sample and the ice melts......... I confess I dunno all the dynamics of all that but it seems a possible risk to an inaccurate reading.... if it matters, which, if you're measuring, it probably does matter.

 

[IslandLizard]

Wouldn't that affect the Brix or OG reading due to freezing and/or condensation from the atmosphere? Frosty mug thang? I hate it when a restaurant or bar pours my beverage into a frosty mug and there's chunks of ice in it. Then if that happens with your sample and the ice melts......... I confess I dunno all the dynamics of all that but it seems a possible risk to an inaccurate reading.... if it matters, which, if you're measuring, it probably does matter.

Ice cold, dry, not frosted.
If the sample is relatively large to the amount of frost clinging to the inside the difference may be negligible. I scoop out about half a cup in a cup size and let it sit for 2-3 minutes on the counter. The small amount that evaporates from the 1/2 cup of liquid won't skew the reading much.

 

[Shwagger]

An eye dropper with several drops of wort in it will cool within a minute or less. Just swirl it in the air a bit. No need for a fridge or icy glasses

 

[IslandLizard]

An eye dropper with several drops of wort in it will cool within a minute or less. Just swirl it in the air a bit. No need for a fridge or icy glasses

That would work very well.
Or swirl one of those plastic sample pipettes with the bulb down in a cup or glass with cold water. Evaporation through the long, narrow spout will be nihil.

 

[wepeeler]

Got it in, wow what a fast and easy way to see if the fermentation was done or not. I was able to see that fermentation was done without having to use large samples of beer.

Alcohol messes with the refractometer, so you won't get an accurate reading. It's for pre-boil and post-boil recordings only.

 

[kh54s10]

I put the hot wort directly on the refractometer. It cools very quickly. I don't appear to be getting high readings from evaporation. My OG after cooling is usually really close. I don't take FG readings with the refractometer. I only take one reading with a hydrometer to calculate ABV if I desire. The once or twice my FG was high I just closed the fermenter up and waited another week.

 

[IslandLizard]

Alcohol messes with the refractometer, so you won't get an accurate reading. It's for pre-boil and post-boil recordings only.

Unless you use a correction formula when alcohol is present. Like Sean Terrill's.
Sometimes we only want an indication of gravity still dropping, measuring differences, to determine if the beer has reached terminal gravity. The absolute FG number is not as important in those cases. One simple drop at a time can get you a lot of useful information. Then take a hydrometer reading, for the record, when packaging.

 

[kh54s10]

Alcohol messes with the refractometer, so you won't get an accurate reading. It's for pre-boil and post-boil recordings only.

You can use it to test for FG. Just get 2 readings that are the same 24 to 48 hours apart. There are also calculators to adjust for the alcohol. Some are more accurate than others.

 

[wepeeler]

Unless you use a correction formula when alcohol is present. Like Sean Terrill's.
Sometimes we only want an indication of gravity still dropping, measuring differences, to determine if the beer has reached terminal gravity. The absolute FG number is not as important in those cases. One simple drop at a time can get you a lot of useful information. Then take a hydrometer reading, for the record, when packaging.

Ah ok. I misinterpreted the post. It can detect changes in gravity, but it won't give an accurate FG reading, without using the conversion formula.