Starting SG query

[Wrongway]

This question is relating to cider making but it will probably apply to wines as well.
I am following a Youtube video on making a gallon of scrumpi using 4L apple juice and 340 gms of sugar. The recipe says to hold back on the 4th carton of apple juice as the fermentation is usually vigorous and will usually fill the airlock etc and to add the last carton when it subsides. Now the problem, how to you work out the starting gravity. If you measure right at the start with only 3L of apple juice the reading wont be the same as if you had the full 4L in. If you measure after adding the 4th carton then that wont represent the true starting SG as quite a chunk of fermentation has already taken place. I have looked for a formula or guide to estimate what the starting gravity should be without much luck.

 

[Chippy_Tea]

When making supermarket juice wine the rule of thumb was to use 1100g of sugar for 13% ABV (4.5 litres)

Is the 340g you quoted the sugar in the cartons or are you adding it to the sugar in the cartons, if its the latter what is the total sugar?

 

[Wrongway]

When making supermarket juice wine the rule of thumb was to use 1100g of sugar for 13% ABV (4.5 litres)

Is the 340g you quoted the sugar in the cartons or are you adding it to the sugar in the cartons, if its the latter what is the total sugar?

It's adding to the sugar in the cartons. If I use the cartons I have then they are 113gms per carton. I think I can see where this is going now. Rather than take an OG reading which isn't really the OG till the 4th carton is added. Work it out from the total sugar used. 113 x 4 = 452gm plus 340g = 792g. I think there is a table formula to convert that to SG.

 

[Chippy_Tea]

Work it out from the total sugar used. 113 x 4 = 452gm plus 340g = 792g. I think there is a table formula to convert that to SG.

Using my back of fag packet calculation i think that will end up around 7%, i am sure the cider makers will correct me if i am wrong.

Edit to add - Having read the turbo cider thread i think it'll be a bit less as i dont think cider will get down to .990 as wine does (again i may be wrong)

 

[Wrongway]

Using my back of fag packet calculation i think that will end up around 7%, i am sure the cider makers will correct me if i am wrong.

Edit to add - Having read the turbo cider thread i think it'll be a bit less as i dont think cider will get down to .990 as wine does (again i may be wrong)

The recipe in the video quoted 8% to 9%. So not too different. Prob trust you fag packet more. It's a first foray into trying a scrumpi.

 

[Cisk]

Why dont you just put your 4lts plus sugar in take your s/g remove 1 lt , put your yeast in wait a day or to and top up with your 4th lt,wait till finished take f/g job done

 

[Chippy_Tea]

If you fill to this level youll be fine then top up with the rest when it has died down, most DJ's are over 4.5 litres you may find you can get all the juice in and still have room to spare.