National Homebrew Club Ireland

General Discussions => Brewing Communities => Belfast Homebrewers => Topic started by: Roo on August 13, 2015, 12:21:50 AM

Title: Everyday's a learning day: Refractometer 101
Post by: Roo on August 13, 2015, 12:21:50 AM
So after buying a Refractometer a while back I thought I was the dogs.

My brews began to suffer but I never linked the two. I thought I was doing something wrong with my yeast as the readings weren't coming close to 1.010....closer to 1.025. Was double pitching, whisking after a week, pitching with and without a starter etc etc. I was having a crisis of confidence.

Turns out the refractometer doesn't give an true reading between pre and post fermentation as the alcohol distorts it. My recent 3.5 ABV are actually closer to 5.5 ABV. It's almost my Eureka moment.

http://www.northernbrewer.com/learn/resources/refractometer-calculator/
Title: Re: Everyday's a learning day: Refractometer 101
Post by: Quiet_Man on August 13, 2015, 12:38:02 AM
Yup. Been down that road too. Still use mine for OG.
Title: Re: Everyday's a learning day: Refractometer 101
Post by: armedcor on August 13, 2015, 12:39:51 AM
Yea they're only really accurate for prefermented wort. There's calculators etc for working out FG but a hydrometer is better I find.
Title: Re: Everyday's a learning day: Refractometer 101
Post by: Beermonger on August 13, 2015, 04:19:39 AM
I find refractometers a pleasure to use and hydrometers a wasteful, timeconsuming and fiddly hassle.

Refractometers work just fine for fermented wort (beer) if you adjust their readings using any of the many calculators available. You need to know the current (apparent) reading from the refractometer plus the original gravity reading to use these calculators.

Conventional homebrewing wisdom says you should take the original gravity with a hydrometer. If you enjoy using a hydrometer, go ahead. Refractometers technically need a conversion factor, but since this is based on wort composition but cannot be easily calculated, and given that it is always within a few percent of unity, there's no point worrying about it. Use a refractometer all the way through and you'll be fine. And happier :).

Title: Everyday's a learning day: Refractometer 101
Post by: Leann ull on August 13, 2015, 08:32:34 AM
Been using a refractor for years, great when measuring the boil, seeing the meniscus using my  hydrometer was a pain in the arse. I only need 2-3 drops of fluid to measure
The formula for calculations now are very accurate.
I was so convinced about it I now have a digital one and it's a joy to use during a boil
My recs would be at least use something to measure gravity, only buy refractometer with brix scale as the relationship to gravity is not linear. Cheap Chinese ones are ok.
If you are on a very tight budget stick with hydrometers
Title: Re: Everyday's a learning day: Refractometer 101
Post by: sub82 on August 13, 2015, 10:51:22 PM
I was not aware of this! Every day is a school day.
Title: Re: Everyday's a learning day: Refractometer 101
Post by: molc on August 14, 2015, 08:46:00 AM
Love my refractometer to monitor the sparge as I go.

How do people usually get a few drops out of the fermentor to measure for the refractometer? I usually use the hydrometer in one of those wine thiefs but it's a pain to have to clean after since its so long.

Sanatised spoon maybe?
Title: Re: Everyday's a learning day: Refractometer 101
Post by: Leann ull on August 14, 2015, 09:09:22 AM
plastic pipette
http://www.ebay.ie/itm/1-2-3-ML-x-100PCS-Graduated-Pipettes-Disposable-Pasteur-Plastic-Eye-Dropper-Set-/171433912653?var=&hash=item27ea41e94d
Dont invert with hot wort from boil it will fly out ;)
Title: Re: Everyday's a learning day: Refractometer 101
Post by: molc on August 14, 2015, 09:23:24 AM
Perfect. I have 1 of those, but I'd never trust it after using once as I can't clean it.

The joys of the disposable world eh? ;)
Title: Re: Everyday's a learning day: Refractometer 101
Post by: mr hoppy on August 14, 2015, 09:31:17 AM
Teaspoon
Title: Re: Everyday's a learning day: Refractometer 101
Post by: Eoin on August 18, 2015, 09:31:23 PM
Best thing for knowing gravity during the boil, it speeds things up no end. Best bit of kit I've bought.