Will wine yeast eventually ferment out all available sugar?

[JimboMarimbo]

I ask because I am using a ‘Magnum’ white wine kit which advises adding 3.5Kgs of sugar to the 1.7 Kgs of concentrated Trebbiano grape juice, adding water to make up to 23 Litre total. My hydrometer reading was 1080 which seemed to equate to a finished ABV of 10.5%. I would prefer a stronger wine nearer the commercial equivalent similar to say, Pinot Grigio, and so I added an extra half kilo of sugar, ending up with an SG of 1086: I assumed this would be well within the ability of the supplied wine yeast/nutrient to ferment out. I have previously used this maker’s wine kits fermenting in a warm area (20-25 degrees C) and after 7-10 days all was complete with a below-zero SG reading. However this has not happened today: after 14 days there are still multiple bubbles erupting from airlock every 8 minutes or so. Curious to see the state of the liquid, I removed the airtight lid and measured the SG at 1004 – medium sweet according to my hydrometer which was covered in small bubbles and needed spinning to get an accurate reading. Obviously fermentation is still going on – my question is for how much longer (CJJ Berry said – sometimes weeks or months) or should I stop the process and resign myself to a medium sweet result – I would prefer to wait it out if eventually I’ll get a great result, but I’m afraid it might just be a waste of time, with hardly any movement on the SG scale after many more weeks.

The opinion of more experienced wine makers would be gratefully received. Thanks in advance.

 

[DBhomebrew]

If it's still going, no reason to resign yourself.

 

[JimboMarimbo]

Thanks, that's encouraging, so patience - until it stops all activity, however long that might be, rather than stopping it prematurely.

 

[DBhomebrew]

Typically, yes. Patience tends to reward makers of fermented beverages. Definitely no reason to stop it prematurely if your preference is for it to continue.

 

[D the Catastrophist]

I have had a wine take almost 4 weeks to ferment down from 1.110 to .97. I have had another wine, using the same yeast do that same sg in a week. This was at similar temps. Yeasts do their own thing, our job is to help them along and then get out of the way. As long as the abv is within the Yeasts tolerance, it will keep eating the sugars.

I have heard it mentioned in various places that the slower fermentation are better as they are less likely to impart off flavors.

 

[JimboMarimbo]

Thanks, that is very reassuring

 

[JimboMarimbo]

Just to conclude this thread - thanks to all - you were absolutely correct; after waiting a total of 20 days, fermentation is complete with a very satisfactory final SG of 994 (from 1086) = ABV of 12.5% - just what I was looking for.

 

[DBhomebrew]

Just to conclude this thread

Kudos for that!