Be part of our community & join our international next generation forum now!
I had some trouble with the ferments not fermenting out far enough.
Starting around 1080 and finishing around 1020.
They didn't taste very sweet though. I thought I'd double check with the old fashioned hydrometer and it's telling me more like 990.
So it seems my process is OK but the meter isn't.
So is the refractometer stuffed or did I just by a piece of cheap crap?
Or am I just doing it wrong?
It seamed kinda idiot proof, it still says 0000 on plain water?!?
It was just a straight sugar wash.
The bit of googling I just did says maybe not so good for FG.
Anyone got an opinion or tip on this?
Comments
@Jacksonbrown, As the wash ferments out, the alcohol concentration rises which impacts on the refractometer readings. This is because refractometers don’t measure gravity, they measure the refractive index. Before fermentation, the two are directly related, but once there’s alcohol in solution they aren’t. Hence the need for an FG calculator.
You can use it to measure your FG, but you also need to know your OG to calculate the actual gravity. Tools such as Beersmith have the calculator build in.
if you want to delve into the detail behind the calcs, look through the following pages in order: http://seanterrill.com/2010/06/11/refractometer-estimates-of-final-gravity/ http://seanterrill.com/2010/07/20/toward-a-better-refractometer-correlation/ http://seanterrill.com/2011/04/07/refractometer-fg-results/
or go to this page for an online calculator http://seanterrill.com/2012/01/06/refractometer-calculator/
Cheers mate. Off the top of your head, how do you think a molasses wort would affect this?
Conventional wisdom states that all the unfermentable minerals etc. wreak havoc with the gravity measurements.
I'm wondering if a good starting °Bx with a good final °Bx measurement will do me, as long as I work out a custom wort correction factor for my specific recipe.
Thoughts?
I reckon you're on the right path as a refractometer measures the refractive index, therefore any unfermentables (I assume) would remain constant in the start & end samples.