First batch wine bad smell but great taste?

[homefarmer]

Hi all,

Have just tested my first batch of wine and it tastes great but has a pretty unpalatable sulfer 'bad egg' smell. My recipe:

Crushed ripe red grapes from my vines in backyard with a steralised 2x4
equalling 10L must.
OG 1.055
Strained off skins and put must in steralised fermenter with 1kg sugar and transferred to steralised glass 10L demijohn.
SG 1.066
Added wine yeast, yeast nutrient and bung with airlock.
Fermented beautifully. I live in Perth, Australia which can be pretty hot and fermentation seemed to be mostly over in a week.
Left for 1.5 months in demijohn.
Just siphoned out a test now that it is cleared and seems finished.
FG is below 1.00?? Well below- FG read 970
Temperature at all times has been averaging 20 degrees C (or 68F)
My questions are:

a) I have NEVER seen a FG reading below 1.00 - is that normal?

and

b) The wine actually tastes great but has an unpleasant sulpher aroma. Will this go away?

Any advice appreciated guys, as I was planning on bottling.

 

[jswordy]

Yes, it is normal for the wine to finish dry at 1.00 or less.

The sulphur smell may be a byproduct of your yeast, which may have been a high SO2 producer. If you will obtain a copper pipe or rod, sanitize it, and stir your wine with it, it will help quite a bit.

The sulphur smell also usually dissipates over long-term aging.

Another technique is to splash rack the wine, allowing it to splash into another carboy. That releases SO2. At the suggestion of a chemist forum member I have taken up racking by putting the racking tube high and on the side of the carboy to create a wall of fluid running down the side, which also releases SO2 and CO2 through the sheeting action. It works great!

I would not bottle until the SO2 issue is resolved to your satisfaction.

 

[robie]

Wines can finish below 1.000 regularly. .997 is pretty typical. The idea is the SG should stop moving down. Once it has stopped dropping and has not dropped for 3 days in a row, it is likely not going to drop anymore.

So, you left the yeast and all the sediment in the wine for 1.5 months? That's a long time setting on all that stuff. Typically what we do is ferment until the SG has stopped dropping. We may leave everything as is for another week, then rack the clean wine off the sediment, stabilize with KMETA if desired, then let the clean wine go ahead and clear over several weeks or months.

The smell you have is very likely H2S or what we called the rotten egg smell. It is almost always caused by stressed yeast, which could easily be the case if you left the yeast in the wine that long.

You can get rid of it, though. First, you should test to see if that is the problem. Here in the US our pennies are copper coated. We put 1/2 cup of the wine in a small container, polish up 2 or 3 pennies really well and put then in the wine. Stir it around for about 5 minutes, then smell the wine again.

If the smell has diminished, the problem is H2S. In your case you will need to find something made of copper or copper coated and test with that. As Jswordy mentioned, stir it with a copper pipe.

Also as he mentioned, you can rack the wine from one container to another, allowing the wine to splash into the receiving container. Do this a couple times.

If the smell still persists, you will need to treat the wine with copper. Here in the States the grocery stores sell a copper mesh pot scrubber. Maybe you can find something similar. Anything very clean, sanitized and made of copper will work as long as the copper is bright and not heavily tarnished. That can be sanitized, dropped into the container of wine and left there for a week or so. Afterward splash rack the wine. That will get rid of the H2S.

Let us know how it turns out.

 

[jswordy]

Right -- H2S.

 

[Rocky]

Just siphoned out a test now that it is cleared and seems finished.
FG is below 1.00?? Well below- FG read 970 Are you sure about this? That is a really low SG. Do you mean 0.997?
Temperature at all times has been averaging 20 degrees C (or 68F)
My questions are:

a) I have NEVER seen a FG reading below 1.00 - is that normal? If you ferment to dry, the SG should always be below 1.000 because your wine is now partially (9-14% depending on the initial SG) ethyl alcohol which has an SG of 0.787.

 

[homefarmer]

Thanks very much Jim! Great info