APPLE WINE – initial SG measurement accuracy

James Burton · Dec 6, 2023

Most fruit wine recipes suggest taking the initial SG reading just before adding the yeast, so that the sugar content can be assessed, and thus we are enabled to calculate the final (potential) alcohol content. It occurs to me that with a fruit wine such as apples, once the pectin is added and fermentation begins, for the next week or so the fruit will break down to a mush and will release, during this period, natural sugars, quantity unknown, into the mash.

Any hope of real accuracy, SG – wise will inevitably be lost: but need the yeast be added for the first week after adding pectin? I’ve not tried this, but would like to sound out your thoughts on this – I propose leaving the muslin bag in the prepared sugar solution, with usual additives and pectin, and letting it break down sans yeast, for a week or so, removing the bag of mush, and then take the initial SG reading, adjusting sugar content if necessary for desired alcohol result (assuming complete 998 or so finish). My worry, I suppose, is, will the fruit ‘go bad’ or otherwise be flavour-degraded, without the fermentation action in this week?

Jon1961 · Dec 13, 2023

James Burton said:
Most fruit wine recipes suggest taking the initial SG reading just before adding the yeast, so that the sugar content can be assessed, and thus we are enabled to calculate the final (potential) alcohol content. It occurs to me that with a fruit wine such as apples, once the pectin is added and fermentation begins, for the next week or so the fruit will break down to a mush and will release, during this period, natural sugars, quantity unknown, into the mash.

Any hope of real accuracy, SG – wise will inevitably be lost: but need the yeast be added for the first week after adding pectin? I’ve not tried this, but would like to sound out your thoughts on this – I propose leaving the muslin bag in the prepared sugar solution, with usual additives and pectin, and letting it break down sans yeast, for a week or so, removing the bag of mush, and then take the initial SG reading, adjusting sugar content if necessary for desired alcohol result (assuming complete 998 or so finish). My worry, I suppose, is, will the fruit ‘go bad’ or otherwise be flavour-degraded, without the fermentation action in this week?

I’ve often wondered this, and suspect that the OG as measured would be an underestimate. But I wouldn’t dare let the fruit hang around for so long without adding yeast.

MashBag · Dec 13, 2023

Yes you can. Keep it properly cool. Sulphite to 50ppm. A very at similar method is used with wine grape wine.

For more info Google "reductive winemaking"

MashBag · Dec 13, 2023

Equally use a refractometer and as long as you get over 20 brix, why worry?

James Burton · Dec 13, 2023

Jon1961 said:
I’ve often wondered this, and suspect that the OG as measured would be an underestimate. But I wouldn’t dare let the fruit hang around for so long without adding yeast.

James Burton · Dec 13, 2023

Well, here's your answer to your fear (and mine) regarding letting the fruit sit without yeast: after three days under sealed plastic bin lid, and post 24 hours campden tablet, there appeared black mould patches on the topside of the muslin bag - calamity!
I pulled the bag out, didn't squeeze it, and threw the still solid apples away. Another dose of campden on the liquid, then 24 hours later pitched the yeast (EC1118 to be safe); thankfully fermentation started normally after a few hours at 24 degrees (C)
I may add that the SG had not altered appreciably from the start.
Shan't be doing that again! Lesson learned.