Refractometer correction???

[stef57]

Hey guys

I recently bought myself a refractrometer from ebay. I brewed with it for the first time a couple weeks ago.
Everything was fine until after fermentation... I didnt realize I had to do some math... ( ok ok. by math, i mean enter a couple of numbers in a calculator and push a button..)

After 5-6 days, i was getting a 7.2 brix reading, according to my chart thats 1029!! way to high. Let it sit for a couple days and no change. I then added 1tsp of yeast nutrient and 1/2 tsp of yeast energizer to give them a little kick in the ass... 2 days later (this morning) still no change!!
At work today, I listen to the latest Basic Brewing podcast. He mentioned an email from someone with the same issue... fortunately for him, he figured out the "refractometer correction" thing before doing anything stupid with his beer.

Well turns out that after using a calculator, my beer sits at 1013! damn close to the 1012 i was shooting for!! never dawned on me to use a hydrometer to check...
Now i have this fully fermented beer with unconsumed nutrient and energizer in it..

any idea if this will leave a nasty taste? or most importantly, is it safe to drink??

 

[Gnomebrewer]

It probably won't hurt, but you could consider adding 100g or so (three to four ounces) of DME (or sugar) to wake the yeast up again (boil it in a bit of water). I don't know how much of the nutrient they'd use up though. Does the beer taste OK?

 

[GrainToGlass]

Sounds like you'll be perfectly fine. If the yeast isn't using the extra nutrients and energizer it should fall out of suspension and down into the trub. If you did overdose it may taste a bit metallic from the zinc or bitter from the magnesium sulphate, but that's just my speculation and I'm sure it's fine. Only you can give us the definitive answer on how it truly tastes. I've stopped using a refractometer a while ago for post-fermentation readings. A hydrometer is more trustworthy and you get to taste how the beer is progressing!

 

[lolcats]

Just cold crash - Then bottle

The correction factor never works. A refractometer for finished beer just gives an indication that the FG is stable.

 

[Yooper]

I always use a hydrometer once fermentation has started, as alcohol skews the reading, but if you want to use a correction table to guestimate the FG, this is the only one I know of that is somewhat close: http://seanterrill.com/2012/01/06/refractometer-calculator/

 

[lolcats]

I always use a hydrometer once fermentation has started, as alcohol skews the reading, but if you want to use a correction table to guestimate the FG, this is the only one I know of that is somewhat close: http://seanterrill.com/2012/01/06/refractometer-calculator/

I used that one and compared to hydrometer readings and was pretty off.

The hydrometer reading was 0.002-0.004 lower...

 

[jddevinn]

I used that one and compared to hydrometer readings and was pretty off.

The hydrometer reading was 0.002-0.004 lower...

Key here is the wort correction factor. This is going to be different from beer to beer.

I use my refractometer to figure out when fermentation has ended. If the recipe is new or experimental then I use a hydrometer for a final reading. however, if the recipe is established the wort correction factor is known from previously and I can use the adjustment formula.

 

[BlkWater_brewer]

Hey guys

I recently bought myself a refractrometer from ebay. I brewed with it for the first time a couple weeks ago.
Everything was fine until after fermentation... I didnt realize I had to do some math... ( ok ok. by math, i mean enter a couple of numbers in a calculator and push a button..)

Did you by chance calibrate the refractrometer prior to use to make sure pure water read 0?

 

[FirstAidBrewing]

Northern Brewer has a good calculator as well that accounts for alcohol in your reading. To answer your other question, you should be fine but if you are worried, just cold crash before bottling/kegging.

 

[stef57]

Thanks for the replies.
I kegged the brew this morning and it did have a slight metallic off taste, nothing major though..
I checked it with a hydrometer before kegging and it's at 1015... a tad high but I'm fine with that

I'll let it for a week or 2 and see what it tastes like after its nice and fizzy..

And yes I did calibrate my refractometer when I received it.

 

[pvpeacock]

Beersmith Lite Version 2.2 has a refractometer tool which converts Brix to Specific Gravity in: 1. unfermented wort and 2. fermenting wort. This corrects for the presence of alcohol. I have this app on my phone and it is great for so many little things like this.

 

[phug]

Thanks for the replies.
I kegged the brew this morning and it did have a slight metallic off taste, nothing major though..
I checked it with a hydrometer before kegging and it's at 1015... a tad high but I'm fine with that

I'll let it for a week or 2 and see what it tastes like after its nice and fizzy..

And yes I did calibrate my refractometer when I received it.

You'll want to calibrate it immediately before each use. Sounds stupid and like a pain in the ass. It's not that bad, takes a few seconds, just keep the tiny screwdriver handy, and a bottle of distilled water with your brew gear.

It will drift out of calibration over the course of a day or with significant temperature shifts of the device.