Calculations

Theoccupier · Mar 9, 2010

Can someone please help?

I started off a blackcurrant tea wine 11 days ago with OG of 1.120 (yes, I double & triple checked and then asked my daughter what she thought).

The airlock all but finished bubbling yesterday (1 bloop per 2-3 minutes) and today the SG is down to 0.986 so I racked it and added CT and stabiliser.

Now I would make that 17.8% but I did top up with about 3/4 litre water after the initial whoosh so what kind of difference would that make? I also intend to back sweeten with white grape juice when I bottle (50ml per bottle ish)

Lynn

oh, and how come nobody warned me not to sniff at the tub of campden tablets to see what they smell like?

Moley · Mar 9, 2010

If you ended up with a gallon then that top-up from 3.75 to 4.5 litres would bring your actual OG down to 1.100 and your ABV to 15.5%.

0.986, are you sure? I've never seen a hydrometer reading that low, have you checked your hydrometer in water at 20Â°C to make sure it reads 1.000 ?

Oh, by the way, don't sniff campden tablets.

Seriously, if anyone's asthmatic DO NOT sniff campden tablets!

Theoccupier · Mar 9, 2010

Cheers Moley.

OK, just checked hydrometer which appears to be working fine. (1.000 at 20degrees)

As I am decidedly new to this, I may not be reading the hydrometer right. There are 5 markers between each number on the scale (ie between 0.990 and 1.000) the level was at 2 points above 0.990 no more numbers above that) so am I right or wrong at 0.986? I think I need to get this right for the future. This is my first attempt. :wha:

Is there anywhere on site that explains the calculations when adding water? My maths aint arf bad so if there's somewhere I can refer to I should be able to work it out myself in the future.

I agree wholeheartedly, DON'T SNIFF CAMPDEN TABLETS. :nono: I can tell you they smell rank and I now have a nostril that feels like it's been burned

Moley · Mar 9, 2010

Theoccupier said:
OK, just checked hydrometer which appears to be working fine. (1.000 at 20degrees)

That's not as stupid as it might sound, I now appear to have collected 6 hydrometers and they read between 0.997 and 1.004 in the same water at the same temperature. The 0.997 is an old plastic beer hydrometer from Boots, circa. 1970, and not to be taken seriously. However, the 1.003 and 1.004 are two (supposedly) decent Stevenson Reeves long-stemmed hydrometers, circa. 1980 and 2009 respectively.

Theoccupier said:
As I am decidedly new to this, I may not be reading the hydrometer right. There are 5 markers between each number on the scale (ie between 0.990 and 1.000) the level was at 2 points above 0.990 no more numbers above that) so am I right or wrong at 0.986?

Sounds to me like you're right, if the .990 was below the surface. You do know to read under the surface, below the meniscus? There's a âHow Toâ somewhere, I will try to find it.

Theoccupier said:
Is there anywhere on site that explains the calculations when adding water? My maths aint arf bad so if there's somewhere I can refer to I should be able to work it out myself in the future.

I don't think so, but if you take the reading you got (1.120), ignore the â1.â and treat that as 120 points, divide that by your final 4.5 litres and multiply it by your original 3.75 then you're heading in the right direction.
I hope that makes some sort of sense, 120 x 3.75 / 4.5 = 100

Theoccupier · Mar 9, 2010

Well thank you very much kind sir.

I did notice the hydrometer has a slight tilt to it so maybe that could affect the reading. Might be worthwhile nipping out and picking up another at some point, it's not like they're expensive and with 3 kids, 3 dogs & 2 cats around the house I'm sure to be breaking them on a regular basis.

I did see a thread somewhere illustrating how to read below the line but it didn't really seem to dip enough to notice. That could explain the low reading. If there was a "dip", that could have taken it closer to 0.988 I'm sure I will get better at this as I go along.

Calculation copied to my little book for future reference :geek:

: cheers:

Moley · Mar 9, 2010

I wouldn't usually expect any wine to finish below 0.990, although it is possible if it's kept fairly warm and there are enough nutrients.

A glass trial jar is useful, so you can see through it rather than trying to guess where the surface level is. Spin the hydrometer between your thumb and index finger (to shake off any bubbles) and try to take a reading just before it stops rotating.

Aleman · Mar 9, 2010

Moley said:
Spin the hydrometer between your thumb and index finger (to shake off any bubbles) and try to take a reading just before it stops rotating.

Even better is to degas the sample before taking a reading . . . Transfer it to a wine bottle . . . add a vacuvin stopper and use the pump to create a vacuum in the bottle . . . the wine/beer will foam . .. allow it to subside then do it again. eventually it stops foaming, and you can take a reading.

Theoccupier · Mar 10, 2010

Hi Aleman. I did the degas bit using 2 djs and shaking until it stopped producing gas.

I think Moley might be right with the glass trial jar suggestion. Mine is a cheapy plastic one from Wilkos and it's not exactly easy to read through.

my shopping list is getting longer..... new glass trial jar (or bud vase or similar).

Oh and yes, the average temp in my kitchen is around 21-22 degrees so it was in a warm place and I added 1tsp nutrient to it (youngs wine superyeast).

I do hope this turns out drinkable after all this.

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