Tracking mead fermentation progress?

Making my first mead now! I've done many homebrew beer batches but I have no experience with wine or mead.

Original sugar reading was 24.2 Brix.
I just took another reading (2 days after pitching) and got 22 Brix.

Using this online calculator with those values:
http://www.brewersfriend.com/refractometer-calculator/

... and it told me I have a negative amount of alcohol...?

How do I know when it's done? I know with beer that when you get under FG 1.02 it's probably winding down, but what is the analogous "done" point for Brix?

 

Quick answer, it's done when it's done....I don't do Brix, so hopefully someone can help you with that.... I use hydrometer to read the original specific gravity, and check it a few times along the line. Mead takes a LOT longer than beer to fully ferment, generally speaking. Relax for a while. Mead is oh so easy to make, just have to be patient. I've got probably 15 gallons that are still in carboys over a year....they're done (verified by a few consecutive hydrometer readings of 0.996), just bulk aging. Like i said, it's done when it decides to be done....could be a month , or several, if not even longer...depending on recipe and fermentation conditions. Could you post up yer recipe? And, at 2 days, I wouldn't be touching it unless you're doing staggered nutrient additions.....relax

 

Yeah I know it's going to take a while, I'm in no rush. I just thought I would take a Brix reading while I had the airlock open to add more nutrients and re-oxygenate. Since I've never done a mead I'm trying to be diligent about record-keeping.

I tried the refractometer calculator at Northern Brewer and got much more sane results (http://www.northernbrewer.com/learn/resources/refractometer-calculator/), so I think the Brewer's Friend calculator may just be defective.

If mead is supposed to finish out around FG 1.000 or 0.995, that corresponds to a final Brix reading of 9 or 10... right?

 

I'm sorry, man, I can't say for sure....just looked at my hydrometer, apparently it DOES have a Brix scale on it....when a specific gravity reads 1.000, the Brix reading is 0, it appears, which makes sense ...water @ 60 F, SG = 1.000 (no sugars in it), so guess Brix would equal 0...again, I don't know - I started reading up on Brix, too much thinking for ths old geezer Hopefully someone who actually knows something useful will help ya out

 

With mead you need to keep abreast of the sugar breaks (30% of the difference between Original Gravity and 1.0 Estimated Final Gravity). At 1/3 and 2/3 of this difference you need to be adding some nutrient additions (See Bray's One Month Mead http://www.homebrewtalk.com/showthread.php?t=429241 for the regimen). Depending on the yeast that you use (wine vs. beer) results in the waiting time for the final product. I recommend a beer yeast.

 

I use brix at the start, convert to sg, and use sg the rest of the time. The formula for brix to abv assumes no alcohol, which makes conversion after fermentation starts tricky. I have taken both brix and sg readings, tried to use the online calculator for brix during fermentation, and not had a lot of luck having them track. Ymmv.
At least with the refractometer, you can see the number is moving during fermentation.

 

A Brix reading of 24.2 is equivalent to a gravity of approximately 1.102 (To convert Brix to SG multiply the reading by 4 BUT refractomers will not provide you with a good Brix (or SG) reading as they use the way that light bends to determine the sugar content but the presence of alcohol changes how light bends). If (IF) you were using an hydrometer and the reading dropped from 24.2 to 22 then that is a gravity of about 1.092. Nothing "negative" about that - still has plenty of sugar for the yeast to work on. A gravity of 1.102 has a potential of about 13 % alcohol by volume (you have converted about 1% of that total) but to realize that potential will depend on proper nutritional feeding of the honey, good temperature control, and the choice of yeast you selected - All I can say is that it is moving in the right direction.