PDA

View Full Version : Best method for testing gravity???



markc23z
11-11-2013, 12:38 PM
So, I've got my first several batches fermenting in 1 gallon glass jugs. I've been testing gravity by extracting samples using a wine thief into a cylinder that has the hydrometer in it. After getting my measurement, I've been reluctant to pour the sample back into the fermenting must. The problem is that after taking so many samples, I'm taking a noticeable dent out of the must, which makes me reluctant to take too many samples.

So, my questions:

1. Should I not worry and just pour the samples back into the must after getting my gravity reading? Wouldn't this introduce oxygen damage problems later in the fermentation?
2. Alternatively, I've thought about putting the hydrometer directly into the 1 gallon jugs to get my measurement. I'm just not sure I'd be able to get it back out. Is this a feasible way of taking gravity readings? If so, how do you get your hydrometer back out?

Thanks!! :)

Honeyhog
11-11-2013, 01:19 PM
As long as you sterilize your hydrometer and wine thief before taking samples it is perfectly fine to dump it back into the carboy. Mead is quite resistant to oxidation but to reduce any oxygenation when taking samples pour up against the side of the vessel so it runs down the sides and creates a minimum of splashing.

fatbloke
11-11-2013, 03:22 PM
As long as you sterilize your hydrometer and wine thief before taking samples it is perfectly fine to dump it back into the carboy. Mead is quite resistant to oxidation but to reduce any oxygenation when taking samples pour up against the side of the vessel so it runs down the sides and creates a minimum of splashing.
+1 on that.

I just sanitise my 100ml test tube, hydrometer and turkey baster.

The sample is drawn with the baster, measured and returned (except for maybe 10 or 20 mls that I'll taste).......

No problems experienced in the 8 or so years I've been making meads....

loveofrose
11-11-2013, 07:10 PM
I sterilize the hydrometer and drop it in. I use plastic jugs, so to get it out I just squeeze the jug till I can grab it!

markc23z
11-12-2013, 02:03 AM
Honeyhog and Fatbloke - do you also sulfite your meads? If so, this would minimize oxidation damage from pouring samples back in, right? What if I am sulfite free - is the oxidation threat from pouring the samples back in still negligible, assuming I'm careful to pour it the way honeyhog describes?

fatbloke
11-12-2013, 02:42 AM
Honeyhog and Fatbloke - do you also sulfite your meads? If so, this would minimize oxidation damage from pouring samples back in, right? What if I am sulfite free - is the oxidation threat from pouring the samples back in still negligible, assuming I'm careful to pour it the way honeyhog describes?
I only sulphite once the ferment is finished. The risk of oxidation is low compared to wines and beers (especially beers) but like rust, its not a quick process. Its mainly about the air/liquid interface. So the amount of time the sample is exposed is negligible. You draw a sample and test it, replace it. CO2 is heavier than air so as long as there's some fermentation then its a non-issue..

Once the brew is complete, when you rack you will disturb some of the sediment - however a small amount - which nucleates and allows some of the carbonic acid to attach and come out as gaseous CO2, so again not a problem. Once most of the sediment has gone, so will a lot of the dissolved CO2 so then you just keep carboys filled up and airspace to a minimum. Hell you can be really anal about it and flood the airspace with CO2 but its not necessary if you use the above method.

The space in a wine bottle is air but you can't remove it all or overfill can you, as the air can only be compressed so much before it pushes the cork back out.......

So of the many possible problems you CAN encounter with wine and mead making, sensible procedure and technique will prevent just about all of them. Don't get hung up on one as it can detract from the fun of the making......

Chevette Girl
11-12-2013, 11:21 PM
I've lowered my hydrometer into a carboy on waxed dental floss (wrap many times and tie it good and tight), but most of the time I plunk the hydrometer right into my wine thief (probably won't work if you're using a thief that fits into a 1-gal carboy).

Returning the sample is fine as long as anything that has touched it has been sanitized.

As Fatbloke and Honeyhog said, mead's pretty resistant to oxidation so I wouldn't obsess about it. Just try to avoid any undue splashing around.

markc23z
11-13-2013, 03:37 AM
Thanks all for the input - it is much appreciated!!

Good to hear I don't need to obsess over this.

One thing I am having a hard time wrapping my head around is this: how is it that if I don't finish a bottle of commercial-made mead within a few days it starts to go bad, but you can rack mead in your home multiple times (exposing it to oxygen every time) and let it sit for months on end aging with no problem??

Not saying I've ever not finished a bottle of mead before it went bad - my wife did it, I swear!! :rolleyes:

GntlKnigt1
11-16-2013, 03:52 AM
I've lowered my hydrometer into a carboy on waxed dental floss (wrap many times and tie it good and tight), but most of the time I plunk the hydrometer right into my wine thief (probably won't work if you're using a thief that fits into a 1-gal carboy).

Returning the sample is fine as long as anything that has touched it has been sanitized.

As Fatbloke and Honeyhog said, mead's pretty resistant to oxidation so I wouldn't obsess about it. Just try to avoid any undue splashing around.

This made me think... why doesn't someone make a hydrometer with a glass loop at the top so you can tie your dental floss to it and retrieve it from a carboy? Hmmmm????

fatbloke
11-16-2013, 06:06 AM
This made me think... why doesn't someone make a hydrometer with a glass loop at the top so you can tie your dental floss to it and retrieve it from a carboy? Hmmmm????
Probably because making them as they do ATM, it's a relatively simple molding etc, a loop would involve a much more complex mold/press process.

Ergo, it's about money........

Despite your suggestion being a good idea........

Don't forget, they just scale down (size/quality/accuracy) the professional ones for the likes of us, and the pro's just take a sample filling the testing container, then that is placed usually in a sink and the hydrometer is dropped in. They'll often leave it for 10 or 15 minutes to settle and take the reading then. The sample is dumped because they can......

You don't have to worry about a small amount of shrinkage in a batch of 3 or 4000 litres do you, whereas us lot, with our piddling little fermenters fret over the smallest of loses.......

Jim H
11-16-2013, 11:37 AM
Professional winemakers put their hydrometers in a wine thief and measure that way, returning the sample.

Perhaps brewers dump the sample to reduce contamination.

fatbloke
11-16-2013, 02:07 PM
Professional winemakers put their hydrometers in a wine thief and measure that way, returning the sample.

Perhaps brewers dump the sample to reduce contamination.
Not the ones I've toured don't....... They may draw the sample with a thief but I've always seen it tested in a standard type testing vessel. Some of the hydrometers have been a lot bigger but with finer scale calibrations (part of a set, seemingly).

I'd also conclude that dumping (or drinking) the test is a safety measure. After all, on a commercial level, its a lot more (money and quantity) too damage. Plus being grape wines, I'd have thought it less resiliant than meads to damage.....

Chevette Girl
11-16-2013, 02:31 PM
The reason you wouldn't produce a hydrometer with a glass loop is that your accuracy is going to depend on the weight of the dental floss involved. I personally subscribe to the "close enough" theory when it comes to gravity readings, but if you're producing a scientific instrument to a particular accuracy, you're not going to throw in this element of error.

Although it would be a good business move, the best way to break a hydrometer is to drop it in the carboy and have it hit bottom or hit the edges or something, they'd be guaranteeing repeat sales! :rolleyes:

GntlKnigt1
11-17-2013, 03:10 AM
Okay.... so who said they have to be made out of glass (and be break-able)?

Perhaps we could collectively design the perfect hydrometer....

fatbloke
11-17-2013, 05:41 AM
Okay.... so who said they have to be made out of glass (and be break-able)?

Perhaps we could collectively design the perfect hydrometer....
Well given that plastics generally, aren't as scratch resistant as glass.....

And what with the commodity pricing of hydrometers that are "accurate enough" for our purposes.......

I suspect we're a few dollars away from the "scratch irrelevant" plastic, bluetooth "connected" hydrometer......:D

GntlKnigt1
11-17-2013, 07:23 AM
Bluetooth...there's another good idea....

Sent from my HTC Vision using Tapatalk 2

joemirando
11-17-2013, 12:32 PM
Well given that plastics generally, aren't as scratch resistant as glass.....

And what with the commodity pricing of hydrometers that are "accurate enough" for our purposes.......

I suspect we're a few dollars away from the "scratch irrelevant" plastic, bluetooth "connected" hydrometer......:D

Bluetooth! EXCELLENT IDEA! Now THAT would be something to crow about. Imagine a thermohydroacidometer! It could send data on density, temp and pH and using something simple like the tried and true 'wedge', dump it all into a spreadsheet!

My only real gripe about LHBS hydrometers is that they always tend to list to one side on me, putting it in contact with the wall of the tube so that I have to basically tilt the whole thing just to get a reading. But that bluetooth thing would make me run out and buy two of 'em. <G>

Joe

Honeyhog
11-17-2013, 02:10 PM
For a more traditional unbreakable hydrometer it could be made from stainless steel but I love Joe's idea of a bluetooth thermohydroacidometer.

GntlKnigt1
11-17-2013, 02:45 PM
Oh man....great idea Joe! Do it all at once. Awesome !

Sent from my HTC Vision using Tapatalk 2

joemirando
11-17-2013, 06:25 PM
<channeling Dr. McCoy>
"Dammit, Spock, I'm a mazer not a computer engineer! You goddamned green-blooded, inhuman..."
</channeling Dr. McCoy>

GntlKnigt1
11-18-2013, 02:24 AM
LOL.... a tricorder for mead....

danr
11-18-2013, 02:47 AM
I suspect we're a few dollars away from the "scratch irrelevant" plastic, bluetooth "connected" hydrometer......:D

I saw THIS (http://www.kickstarter.com/projects/parasitx/the-beerbugtm-digital-hydrometer) digital Bluetooth or WiFi hydrometer on Kickstarter a while back (real time S.G., Temp, Alcohol%). It looks like they have started shipping the Bluetooth version to their backers. I couldn't justify the cost, but it is a great concept.

You can put your name on an email list to be notified when their commercial versions are available on their website: http://www.thebeerbug.com/

joemirando
11-18-2013, 01:27 PM
I saw THIS (http://www.kickstarter.com/projects/parasitx/the-beerbugtm-digital-hydrometer) digital Bluetooth or WiFi hydrometer on Kickstarter a while back (real time S.G., Temp, Alcohol%). It looks like they have started shipping the Bluetooth version to their backers. I couldn't justify the cost, but it is a great concept.

You can put your name on an email list to be notified when their commercial versions are available on their website: http://www.thebeerbug.com/

Oh man, they stole OUR idea! <LOL>

drako824
11-18-2013, 06:39 PM
I saw THIS (http://www.kickstarter.com/projects/parasitx/the-beerbugtm-digital-hydrometer) digital Bluetooth or WiFi hydrometer on Kickstarter a while back (real time S.G., Temp, Alcohol%). It looks like they have started shipping the Bluetooth version to their backers. I couldn't justify the cost, but it is a great concept.

You can put your name on an email list to be notified when their commercial versions are available on their website: http://www.thebeerbug.com/

Awe you beat me to it, I was gonna post that link

MourneMead
11-22-2013, 04:45 AM
Hi,

It's my first post so a "Hi" too...

I make my mead in demi-johns (1 galleon) and when I take hydrometer readings I put the (steralised) hydrometer in the top and use a long cut elastic band tied around the top so I can pull it out again - the rubber gives good grip and you don't have to tie it too tightly and maybe break the hydrometer. I can usually see through the glass enough to take a good reading.

cheers...