Calculation errors?

[JPVagabond]

I broke my hydrometer this morning. Which was very frustrating. As I had already begun I didn't want to waste the ingredients. So I ploughed ahead. I had read that it is possible to determine specific gravity without a hydrometer using mass over volume so I gave it a go.

Handily. Mass was 4kg and volume was 4litres. So I had a density of 1. And original gravity of 1. I used a conversion chart to calculate how much sugar I needed to add to increase the og to one that would yield a 13% wine (1.095/1.1). But on weighing I was only at 1.06.

Can anyone give me any indication as to where I have gone wrong. I suspect it will have something to do with the low sugar composition of the juice (no added sugar) there was only 12g to start with. But then I thought I had added the right amount of sugar.

If it emerges I need to add more sugar. Can I please add this on day 2?

Ps. I know I will end up with a potentially too sweet and probably disgusting wine due to the sweetener. This is largely why I ploughed ahead. My hope is that it would be strong enough that I wouldn't care. Which is why I'm keen to get the calculations right.

Thanks in advance

 

[sour_grapes]

It is not clear to me exactly what you did. I would be happy to try to help more later. Can I suggest that you take a look at FermCalc, and see if that answers your question? If not, I will try to help if you clarify EXACTLY what you added to the vessel.

Here is FermCalc: FermCalc Winemaking Calculator

 

[JPVagabond]

Ok. I'm completely lost.

I downloaded fermcalc (useful. Thank you). It told me what I needed to do.

The main problem I have now is that it give cometely different figures to this resource: Adjusting Specific Gravity which I followed initially.

I've now added an extra 350g sugar. As directed by the above resource. In order to get up to 1.095

But I'm now ending up with an og of 1.12.

According to fermcalc I would have needed an additional 495g sugar to get to 1.095. but according to beer- wine.com adding just 350 has surpassed it.

Ive now got no idea how this is going to go or if my measurements and calculations are even slightly correct.

Im fairly sure my og is somewhere between 1.06 and 1.12. which is a sizeable margin.

I can tell you knat I know. I started with 4litres of juice. With a specific gravity of 1. I added 915g sugar in approximately 500ml water.

I know I've not made things easy. And like I said I'd like the wine to be semi drinkable. I'm not too worry about the overall outcome purely because I knew I would cock it up but had already begun. But my frustration leads me to want to find out where I went wrong. Also so I don't do it again.

And I would like to have an idea of my end abv.

Thanks everyone

 

[sour_grapes]

But I'm now ending up with an og of 1.12.

How do you determine it is 1.12 if you do not have a hydrometer?

 

[JPVagabond]

How do you determine it is 1.12 if you do not have a hydrometer?

Use mass over volume to get density. To get specific gravity you just need to divide by the density of water, which is 1 anyway.

In the end I've disregarded that.
I've worked only with what I know yo be true. And I've lost confidence in my scales. So I used fermcalc and the known weight of sugar I added.

Also. I've concluded that the other resource was US Gallons. Which is why my calculations wee thrown off. I think everything actually works out now.

 

[mikewatkins727]

May I suggest when you replace you hydrometer, you replace it with two. That way you have a backup when you do again what you just did.

 

[sour_grapes]

Use mass over volume to get density. To get specific gravity you just need to divide by the density of water, which is 1 anyway.

In the end I've disregarded that.
I've worked only with what I know yo be true. And I've lost confidence in my scales. So I used fermcalc and the known weight of sugar I added.

Also. I've concluded that the other resource was US Gallons. Which is why my calculations wee thrown off. I think everything actually works out now.

Ah, yes, surely it was US gallons. Damn factors of 6/5!

I speculated that you were taking mass over volume, but I was wondering how you were measuring the volume!