Wilkos sauvignon blanc

[Tommcd]

Hi everyone wonder if someone could help.
Whilst in wilkos today seen the kit and thought I would give it a go.
In the instructions it says about topping up the demiJohn a couple of days in.
And was wondering how will this affect my original gravity reading as surely the water added will lower the gravity or will it not affect it?

 

[TonyP]

Yes, adding anything will impact SG. Water, with a SG of 1.000, will lower the SG.

 

[Tommcd]

Yes, adding anything will impact SG. Water, with a SG of 1.000, will lower the SG.

Yer that's what I thought so how would I work out the added water affecting the original gravity, is there a sum for this? Or is it because the added watter is boiled then cooled it doesn't affect it?

 

[sour_grapes]

The boiling/cooling is not at all relevant to this.

If you took a SG reading before fermentation started, you can work out the answer to your question using FermCalc: FermCalc Winemaking Calculator

I am unfamiliar with this kit, but here is my inference based solely on reading those instructions. They formulate the kit so that, in the end, it will have the right ABV. However, they have you withhold some of the required water initially so that there is empty space in the demijohn to start with. They do this because the initial, vigorous fermentation would foam up and overflow the container. After that phase of the fermentation is over, you then add water to get to the "right" level of ABV when the fermentation is completed.

You can, of course, withhold some of the water to make a stronger drink with more body, but you risk having it out of balance.

 

[Tommcd]

Yer it does say on there that it's aiming at 12 % but wondered if anyone knows how to actually work it out with adding the water as I have looked online every where and cant seem to find out the sum for it.
Thanks for your reply

 

[sour_grapes]

If we assume that it would be 12% if done to instructions, the math for figuring out the ABV if you withhold the extra water is easy. However, you would have to tell us what volume this wine kit was supposed to make.

 

[Tommcd]

If we assume that it would be 12% if done to instructions, the math for figuring out the ABV if you withhold the extra water is easy. However, you would have to tell us what volume this wine kit was supposed to make.

It's saying its 12% approx for 4. 5 ltrs I'm going to do it to the instructions and make the 4.5 ltrs I just didn't know if there was a calculation for adding water it generall after the first few days of fermentation as I made a wine from juices the other day and the one I was following said to top up with water and didn't know how to work it out so added more juice and worked out the sugar added per ml in the juice.

 

[sour_grapes]

It's saying its 12% approx for 4. 5 ltrs

I see. I misread the directions. We could still figure it out if we knew the volume of that can of concentrate you added in the beginning. However, if you are making it to instructions, no real reason to do so.

 

[Tommcd]

I have added in the photo of the contents of the can. It's more for when Im making my own wines that I know how to work out how much water added affects how it dilutes the wine.

 

[sour_grapes]

For your own wines, the formula relating alcohol before and after water addition is simple. If the initial volume of your wine is Vstart, and has alcohol content (ABV) of Astart, and you add a volume Vwater of water, then your final alcohol content Afinal is given by:

Afinal = Astart * Vstart / ( Vstart + Vwater)

 

[Tommcd]

For your own wines, the formula relating alcohol before and after water addition is simple. If the initial volume of your wine is Vstart, and has alcohol content (ABV) of Astart, and you add a volume Vwater of water, then your final alcohol content Afinal is given by:

Afinal = Astart * Vstart / ( Vstart + Vwater)

Thank you massive help

 

[Tommcd]

For your own wines, the formula relating alcohol before and after water addition is simple. If the initial volume of your wine is Vstart, and has alcohol content (ABV) of Astart, and you add a volume Vwater of water, then your final alcohol content Afinal is given by:

Afinal = Astart * Vstart / ( Vstart + Vwater)

Sorry to be a pain
So I have done a sum on something random .I've now had to learn bodmas and then found out my phone can do it. put it in a calculator and it has given me an answer of 0.88 would that be classed as 1.088 or have I got it completely wrong?

 

[sour_grapes]

You did the sum correctly, bodmas wise, but I think you are misinterpreting the formula I gave you.

I wrote above that Afinal and Astart were supposed to be the percentage of alchol (ABV). This is what it lists on the side of your beer bottle (~5%) or your wine bottle (12-14%).

It looks like you actually would like the formula for computing the specific gravity.

In that case, the formula would be:

SGfinal = (SGconc * Vconc + 1.000* Vwater) / (Vconc + Vwater)

where "conc" above means concentrate, SG means specific gravity.

So, in the example that you were doing on your phone, the calculation would be

SGfinal = (1.100*4.0 + 1.000*1.0)/(4.0 + 1.0) = 5.4/5.0 = 1.080.

The calculations are similar in spirit, but water has 0 alcohol, but it has a SG of 1.000.



I do hope that you were not one of the kids in school who said "Why should we learn maths? We will never use it once we get out of school!"

 

[Tommcd]

You did the sum correctly, bodmas wise, but I think you are misinterpreting the formula I gave you.

I wrote above that Afinal and Astart were supposed to be the percentage of alchol (ABV). This is what it lists on the side of your beer bottle (~5%) or your wine bottle (12-14%).

It looks like you actually would like the formula for computing the specific gravity.

In that case, the formula would be:

SGfinal = (SGconc * Vconc + 1.000* Vwater) / (Vconc + Vwater)

where "conc" above means concentrate, SG means specific gravity.

So, in the example that you were doing on your phone, the calculation would be

SGfinal = (1.100*4.0 + 1.000*1.0)/(4.0 + 1.0) = 5.4/5.0 = 1.080.

The calculations are similar in spirit, but water has 0 alcohol, but it has a SG of 1.000.



I do hope that you were not one of the kids in school who said "Why should we learn maths? We will never use it once we get out of school!"

You are absolutely amazing!
Yer sorry I did think it might have been the percentage but thought that was to straight forwards.
One day I will get there it's leaning all these little things and you have been a great help thanks you.

Yer to be honest I was one of them kids I thought aslong as I have a calculator I'm ok and now I'm a sheet metal engineer and use maths every day