Hydrometer question

[Marshall]

I just got my hydrometer in the mail. I'm doing a batch of mead in the morning. Can someone tell me what to test and when? Or is there a tutorial the explains it?

 

[fatbloke]

I just got my hydrometer in the mail. I'm doing a batch of mead in the morning. Can someone tell me what to test and when? Or is there a tutorial the explains it?

There's no real "tutorial". I'd have filled a test jar with water at the "calibration" temperature (should say either on the hydrometer scale, or with any packaging/instructions - often something like 60F or even 15 to 20C), then one the hydrometer settles in the water it should read 1.000

Mixing the honey with water, then taking a sample in the test jar and putting the hydrometer in (sanitise the hydrometer and jar with your usual sanitiser and you can generally just put the sample back into the batch). Once it settles, you take the reading (depends on what the scale actually is and/or how many scales are printed on the number guide inside the device). Either specific gravity or brix will give you enough info (I use gravity, as do a lot of others - or so it seems). It's measuring the sugar content of the liquid.

With the numbers, consider 1.000 as finished or final gravity, though it's easily possible for a batch to go dry and get readings in the 0.990-0.980 area too. If the hydrometer has "potential alcohol" or other scales, unless they're "recognised" scales I'd say ignore them.

Now the distance between the starting gravity before pitching yeast and the gravity when it's finished, will tell you the likely alcohol content i.e. 1.100 start, with 1.000 finish or a 100 point drop, will mean about 13.5% ABV strength - a lot of the wine yeasts will manage 14% or so quite easily, some will go higher.

Don't forget, the ability to produce alcohol isn't an infinite thing with yeast so you can't just keep putting extra honey/sugars into the mix. It can get or be too high, causing the yeast "osmotic shock" and it not starting to ferment at all. Plus if you did want to go for, say, 18% ABV, which is the published tolerance for the likes of EC-1118, DV10, K1V-1116 etc, then you'd need a gravity drop between the start and finish numbers of 133 points, yet the problem can be that using a starting gravity of 1.133 can cause issues getting the batch started, so it's often thought best to start lower, then at certain points, adding a bit more honey to bring the gravity back up some, but then adding the numbers/drops in gravity together will tell you when to stop adding more to allow the ferment to achieve the 18% mark etc.

It's not quite so easy to achieve higher strengths as it may seem.

You can use the hydrometer to test regularly, to monitor how the ferment is progressing, obviously, proper sanitisation of the kit i.e. hydrometer, testing jar, and whatever you use to draw the sample from the batch. Some don't put the sample back, I always do, just keeping 10 or 20 mls back to taste to understand how it's progressing flavour-wise as well as following the numbers.

When the bubbles have either slowed or stopped in an airlock, don't presume that the ferment is complete, you'd want to see 3 identical readings taken across the period of about a week (3 or 4 days apart), only then presume finished (if below about 1.020 but that would depend on what your starting numbers were, as to whether it's finished or stuck - stuck ferments are another story......)

 

[Marshall]

There's no real "tutorial". I'd have filled a test jar with water at the "calibration" temperature (should say either on the hydrometer scale, or with any packaging/instructions - often something like 60F or even 15 to 20C), then one the hydrometer settles in the water it should read 1.000

Mixing the honey with water, then taking a sample in the test jar and putting the hydrometer in (sanitise the hydrometer and jar with your usual sanitiser and you can generally just put the sample back into the batch). Once it settles, you take the reading (depends on what the scale actually is and/or how many scales are printed on the number guide inside the device). Either specific gravity or brix will give you enough info (I use gravity, as do a lot of others - or so it seems). It's measuring the sugar content of the liquid.

With the numbers, consider 1.000 as finished or final gravity, though it's easily possible for a batch to go dry and get readings in the 0.990-0.980 area too. If the hydrometer has "potential alcohol" or other scales, unless they're "recognised" scales I'd say ignore them.

Now the distance between the starting gravity before pitching yeast and the gravity when it's finished, will tell you the likely alcohol content i.e. 1.100 start, with 1.000 finish or a 100 point drop, will mean about 13.5% ABV strength - a lot of the wine yeasts will manage 14% or so quite easily, some will go higher.

Don't forget, the ability to produce alcohol isn't an infinite thing with yeast so you can't just keep putting extra honey/sugars into the mix. It can get or be too high, causing the yeast "osmotic shock" and it not starting to ferment at all. Plus if you did want to go for, say, 18% ABV, which is the published tolerance for the likes of EC-1118, DV10, K1V-1116 etc, then you'd need a gravity drop between the start and finish numbers of 133 points, yet the problem can be that using a starting gravity of 1.133 can cause issues getting the batch started, so it's often thought best to start lower, then at certain points, adding a bit more honey to bring the gravity back up some, but then adding the numbers/drops in gravity together will tell you when to stop adding more to allow the ferment to achieve the 18% mark etc.

It's not quite so easy to achieve higher strengths as it may seem.

You can use the hydrometer to test regularly, to monitor how the ferment is progressing, obviously, proper sanitisation of the kit i.e. hydrometer, testing jar, and whatever you use to draw the sample from the batch. Some don't put the sample back, I always do, just keeping 10 or 20 mls back to taste to understand how it's progressing flavour-wise as well as following the numbers.

When the bubbles have either slowed or stopped in an airlock, don't presume that the ferment is complete, you'd want to see 3 identical readings taken across the period of about a week (3 or 4 days apart), only then presume finished (if below about 1.020 but that would depend on what your starting numbers were, as to whether it's finished or stuck - stuck ferments are another story......)

Thank you for the help.

 

[saramc]

This is a STICKY in the Beginner's section on this forum: http://www.winemakingtalk.com/forum/f5/how-use-hydrometer-newbies-16574/

And this came up as top choice when I plugged in "video on how to use hydrometer" in my search engine.....[ame]http://www.youtube.com/watch?v=GTvmYaQq6Mc[/ame]

The most important things to remember, for me:
1. Make sure you have a BACKUP HYDROMETER, because they break at the most inopportune time!
2. Make sure you know the calibration point for your hydrometer.
3. Make sure it is clean and sanitized.
4. Use it to measure JUST liquid (and this liquid is degassed) because solids and gas can impact the result. *Can use a REFRACTOMETER to measure sample of fruits that may not provide a lot of juice initially, or perhaps you are in the field and want to know the Brix level of a particular fruit.

 

[fatbloke]

This is a STICKY in the Beginner's section on this forum: http://www.winemakingtalk.com/forum/f5/how-use-hydrometer-newbies-16574/

-----%<-----

Damn that's handy to know. It'll save me typing my burbling out another time.....

 

[J-Gee]

Excuse me Bloke,but I had to chuckle at your burble...knowing that there is a sticky on the subject.Have a good day,sir.I enjoy your input.