Help with hydrometer

[Leo]

OK, so I just strained my first ever batch of wine (plum wine) from the fermenting bucket to the demijohn.

There was a bit more in the bucket than would fit in the demijohn so i decided to try some and take a hydrometer reading. (It had been fermenting for a week).
The wine smells fairly alcoholic and tastes very pleasant and dry. But when i took hydrometer readings, with both my hydrometers, they gave the same reading for water when i calibrated them as they did for the wine. There is a chance the water may have been a few degrees warmer, but not noticeable to the touch.
I forgot to take a hydrometer reading at the beginning, but here is the recipe:
3.5 lbs fresh plums
0.5 lbs sultanas
2 lbs sugar
1 gallon of water.

I cant take another reading until i bottle it, but how can i work out the abv % approximately? I'm not too concerned about it being very accurate.

 

[Marrsy86]

Hi,

I'm not sure there is an accurate way but I guess you can check this thread out. There are two charts in there, one linked by me and one linked by HLA91, have a read of the thread and check out the chart linked by HLA91, that might give you an estimate.

Cheers

Marrsy

 

[Runwell-Steve]

Your hydrometer is not going to help you if you don't know how much sugar was in there in the first place. You should take a reading before fermentation starts, and then again when it is finished and compare the difference.

I think plums contain approx 7.5g of sugar per 100g of fruit, 85% moisture content
Sultanas contain approx 65g sugar per 100g. 15% moisture content.

2lb of sugar in 1 gallon of water will give an OG of approx 1.078
Your fruit with all the sugar and juice extracted should add approx 2 pints of liquid and approx 10 oz of sugar.

So your total recipe is

10 pints liquid
2lb 10oz sugar

According to the table linked to 2lb 10 oz in a gallon would be an OG of 1100, but you are in 10 pints so that would reduce to 1.080

An OG of 1.080, according to the table should give you alcohol of 10.6%

I hope I worked that out correctly. Having never made wine before I had to google everything.

Next time don't forget to use your hydrometer before it starts fermenting.

 

[Leo]

Thanks. Its not a mistake I will make twice.

The main thing i wasnt sure about was how to work what my original gravity would have been from the amount of sugar in the recipe.

 

[smoothlager]

I cant take another reading until i bottle it, but how can i work out the abv % approximately? I'm not too concerned about it being very accurate.

If you assume as suggested that it was an SG of 1.080 at the start then you can make a calculation before bottling with your hydrometer by dividing the overall drop by 7.36.

The wine is likely to finish fermenting somewhere between SG 1.000 and 0.990.

Example.

If it finishes at 1.000 then calculate a drop of 80/7.36= 10.86% (10.9%)

If it finishes at 0.995 then 85/7.36= 11.54% (11.5%)

at 0.990 90/7.36=12.22% (12.2%)

So its gonna be somewhere between 10.9 and 12.2%

Hope this helps