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Saratoga
03-06-2015, 05:03 PM
As above. I have fermented mead, but how can I tell its strength, short of drinking etc.
Apologies for my idiocy and thank you for any help.

bathtub brewer
03-06-2015, 05:22 PM
Do you mean you forgot to check specific gravity? If you let it ferment till it's done you could get close just by knowing what type of yeast you used.

brentG
03-06-2015, 05:23 PM
Take a gravity reading now, so you know where it's at, then use the mead calculator and plug in the ingredients you used to get a ballpark of where you started.

brentG
03-06-2015, 05:25 PM
Do you mean you forgot to check specific gravity? If you let it ferment till it's done you could get close just by knowing what type of yeast you used.

You can push yeast well past its tolerance, or it could have stalled. Using a hydrometer is the recommended way of measuring.

bathtub brewer
03-06-2015, 05:47 PM
Yes, I realize a hydrometer is the preferred method. I was just trying to say under less then ideal circumstances you might be able to get close from knowing how your yeast behaves.

Saratoga
03-06-2015, 07:38 PM
Do you mean you forgot to check specific gravity? If you let it ferment till it's done you could get close just by knowing what type of yeast you used.

Yes sorry - specific gravity. I used Lalvin wine yeast, with my own "grown" honey. It is done fermenting.

Saratoga
03-06-2015, 07:44 PM
You can push yeast well past its tolerance, or it could have stalled. Using a hydrometer is the recommended way of measuring.

Also is there a simple strip of "paper" I can add to the brew that estimates % alcohol? Kind of like a breathalyser...

Stasis
03-07-2015, 06:24 AM
As far as I know only a vinometer can calculate the alcohol content. But vinometers are inaccurate and only work for dry wines/meads. Just about nobody in this forum suggests using one. Easiest way is to use a hydrometer. Take a reading now, plug in the ingredients and amounts into the mead calculator and you will get a good estimate

Medsen Fey
03-07-2015, 08:58 AM
Also is there a simple strip of "paper" I can add to the brew that estimates % alcohol? Kind of like a breathalyser...
A breathalyser is a very interesting thing to ask about. It might be fun to take a sample of air from the headspace of a batch and push it through a breathalyzer to see if it correlates with the ABV. You'd probably be able to publish a nice article in Zymurgy or some other journal.

Labs have a variety of methods to measure alcohol including spectrophotometry, and chromatography and for a true measurement you can send a sample to a wine lab. That's probably overkill for most of us.

The method mentioned above, using an estimate of original gravity and the current gravity will work for the calculations.

You can also take a hydrometer reading and a refractometer reading at the same time and use a formula to calculate the ABV. There are websites with calculators online such as vinocalc that you can plug the numbers into for easy use. There is a thread here, if you search, on improving on these formulas if you are into the math.

There is another method called "spirit indication" where you boil off the alcohol and take hydrometer readings. There's a calculator on vinocalc that will work the numbers. If you search SPIRIT INDICATION you'll find some threads that discuss it. To be close to accurate you really need fine-scale hydrometers.

All of the home methods will give you an ESTIMATE of ABV. None of them are perfect and you may be +/- 1% or more easily so try not to get too worked up over it.

Sent from my THINGAMAJIG with WHATCHAMACALLIT

bernardsmith
03-07-2015, 10:28 PM
As above. I have fermented mead, but how can I tell its strength, short of drinking etc.
Apologies for my idiocy and thank you for any help.

Assuming that your honey has about the same percentage of water in it as all other honey and assuming that 1 lb of your honey dissolved to make 1 gallon (US) of must will increase the gravity by 40 points then if you know a) the quantity of honey you dissolved and b) the volume of the liquid into which you pitched the yeast then you can easily estimate the starting gravity.
In other words, if you dissolved 2.5 lbs of honey and had 1 gallon then your SG would be about 1.100. If you can estimate the starting gravity then if you multiply that by 131 this will give you a good estimation of the potential ABV. (if it was 2.5 lbs of honey and you were making 1 gallon of mead, then the potential total ABV would be about 13%) You don't really need any high tech equipment.