Hydrometer help

[Mikhail Bulgakov]

Hi all,
I'm a total novice wine maker having just made my first two wines, one from a kit and one mongrel brew of supermarket grape juices, both with highly satisfactory results, I'm keen to repeat these yet would like to be able to calculate the ABV.

I've read plenty about hydrometers and how to use them, but I'm still a little confused as to how this would work with a kit wine. Do I take the first measure from the mix of concentrate, water and sugar that half fills the demijohn in the first step? The adding of water having no effect on the overall calculation?

Similarly when following the guide I used for my juice mongrel, it called for adding half of the juice for the initial fermentation then topping up with more after the initial flurry. Would that effect it also?

I apologise in advance if I sound stupid, I'm just a complete dilettante :)
Thanks :)

 

[chrig]

Yes you are correct as to when you take the reading, once you add extra water you can calculate how much it would dilute the final abv. So long as you know how much water you add. Its not an exact science at this level, but we can get close enough to know what'll make you fall over after a bottle :lol:

 

[coyspurs]

Would love to know the answer to this as well :thumb:

Mike

 

[Chippy_Tea]

The kits I have mad have all given the ABV either on the box or in the instructions.

 

[Mikhail Bulgakov]

Yes you are correct as to when you take the reading, once you add extra water you can calculate how much it would dilute the final abv. So long as you know how much water you add. Its not an exact science at this level, but we can get close enough to know what'll make you fall over after a bottle :lol:

Any chance you can explain the calculation buddy? I know I'm a pest, I could just use all the help I can get thanks!

 

[Mikhail Bulgakov]

The kits I have mad have all given the ABV either on the box or in the instructions.

They do state approx ABV but I'd like to be able to check progress, specially whilst the temperature is fluctuating a bit in winter.

I'm more interested in calculation for the supermarket juice wines

 

[oldbloke]

It is of course easiest if the complete wort is available to take a reading from. One solution is to make up the complete wort, then set some of it aside in the fridge for the topping up - so you top up with the same gravity stuff you took your reading from. So all you need is that OG reading and another FG reading.
Otherwise...
Take a reading at the start, then another just before you top up. Work out how much alcohol you've made so far (convert the ABV to ml). Make a note of it!
Top up and take another reading, then take your final reading, and from those work out how much more alcohol you made after topping up.
Add the two lots of alcohol together and convert back to ABV.

 

[morethanworts]

If I've understood your question, you can measure the gravity of the mixed must before topping up and then use our forum calculator here(the OG expected one) to work out what the OG would have become after top up.

Then use an ABV calculator when it's fermented out, as normal.

 

[Chippy_Tea]

I'm more interested in calculation for the supermarket juice wines

The rule of thumb is if you use a total of 1100g of sugar (including the cartons) in a DJ and let it ferment to 990 you will end up with an ABV of 13%

 

[Tim_Crowhurst]

I start the wine off in a 3 or 5-gallon bucket (depending on how much I'm making) and transfer to DJ after 7-10 days. That way you don't have to top up, and you don't have to recalculate the hydrometer reading.

 

[Mikhail Bulgakov]

Thanks for very useful replies! Most helpful!

If 1100g sugar will result in 13% abv is there a formula I can use to tailor the sugar to 11 or 12% abv?

 

[oldbloke]

Near enough, 20gm per litre gives 1%

aka 100gm per litre = 5%

aka 1lb per gallon = 5%

aka 2oz per pint = 5%

Or there's this chart:
http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm

 

[narmour]

There's a useful calculation in this post from Moley.... it's in the "The Maths" section just before half way down.

http://www.thehomebrewforum.co.uk/viewtopic.php?f=48&t=10179

:hat:

 

[houghton19]

Sorry to jump on your thread, i was gooing to start a new one, Im a newbie too but think i have made a poopoo out of it, I am trying 2 choc wines, 1 choc/strawberry and 1 choc/cherry, using ice cream syrup, I added the syrup to water & sugar (1kg in each batch) and topped up to about 5ltr, if i have taken the measurements right the strawberry is 1.82 amd cherry is 1.92, are these right or have i done it wrong with doing it after i topped it up with water.

Thanks

Tim.

 

[oldbloke]

1.82 isn't a feasible hydrometer reading
1.082 is

 

[Mikhail Bulgakov]

Hi mate
Chances are you're misreading your hydrometer, have a good look at the scale and you'll likely realise your readings are 1.082 and 1.092. From one newb to another haha! Made a similar mistake myself when I started.

I feel less like the new boy now

 

[Chippy_Tea]

This explains it -