strang Sg

[hamidreza]

hi all
i have started with SG 1.130 and used lalvin EC1118 yeast the problem is that i still have the cap but the Sg now is 0.994 or even lower. how can it be possible? fermentation is still going
has the high level of alcohol caused this fault in Sg ? if so how can we know the exact of amount of alcohol produced or the sugar consumed using a Hydrometer?

the taste of the wine is more bitter than normal. can this be reason of low sg?

dose the amount of acids in the win have any roll in Sg. for example tartaric acid can bring the sg down?

 

[Ajmassa]

That's a head scratcher. I never heard of acids affecting the hydrometer reading before but I suppose anything is possible. Pretty sure tartaric does not affect sg. And the alcohol content is accounted for on the hydrometer for accurate SG readings- unlike a refractometer.
Maybe the high amount of alcohol (18%!) has something to do with the cap still formed.
Is it still a strong dry cap? Have you been punching down? Was it a fast ferment? And did you have any temperatures out of the norm? I'm assuming this is grape wine.
To me all wines freshly fermented seem bitter. And a Ferment too strong is better than the opposite.
If mine I guess I'd press and rack to glass. Give it a day or so and rack again. At that point maybe give it a week to monitor/check acid levels/taste and reevaluate.

 

[salcoco]

your wine has completed fermentation bitterness is due to tannin. press accordingly. rack after three days off of gross lees, then rack again in three weeks. wait another month and do taste tests.

 

[jgmann67]

Let's address this one in three parts :

a. I'm not sure what the concern is that you're at an SG of 0.994. It's entirely possible (and happens all the time, actually) that a wine will ferment below 1.000. Wines will routinely ferment down to an SG of 0.990. So, don't panic - getting below 1.000 just means you've done a great job keeping for ferment healthy. Are you sure your OG wasn't 1.103? With an OG at 1.130, you're fermenting into the 18% range (18.4% if fermented down to 0.990). 1.103 gets you into the 14% range (great for most reds).

But the only things that I know of that will affect your SG are: temperatures, sugar and human error. A mass of CO2 can also throw off a reading, but in the opposite direction (it will give you a reading higher than it actually is)

b. What you consider an active ferment might just be the release of the CO2 byproduct of a happy fermentation. As you punch your cap, you'll get lots of fizzy goodness. That's good... normal...

c. Is it bitter or sharp? Wines with a lot of CO2 in it are typically very sharp. Take a sample and degas it (put it in a bottle and shake the bah-jeebers out of it for a few seconds), then taste. If it's bitter, you'll want to run your numbers (pH and TA).

 

[hamidreza]

Let's address this one in three parts :

a. I'm not sure what the concern is that you're at an SG of 0.994. It's entirely possible (and happens all the time, actually) that a wine will ferment below 1.000. Wines will routinely ferment down to an SG of 0.990. So, don't panic - getting below 1.000 just means you've done a great job keeping for ferment healthy. Are you sure your OG wasn't 1.103? With an OG at 1.130, you're fermenting into the 18% range (18.4% if fermented down to 0.990). 1.103 gets you into the 14% range (great for most reds).

But the only things that I know of that will affect your SG are: temperatures, sugar and human error. A mass of CO2 can also throw off a reading, but in the opposite direction (it will give you a reading higher than it actually is)

b. What you consider an active ferment might just be the release of the CO2 byproduct of a happy fermentation. As you punch your cap, you'll get lots of fizzy goodness. That's good... normal...

c. Is it bitter or sharp? Wines with a lot of CO2 in it are typically very sharp. Take a sample and degas it (put it in a bottle and shake the bah-jeebers out of it for a few seconds), then taste. If it's bitter, you'll want to run your numbers (pH and TA).

thanks alot for your reply
there is not any problem yet .but i dont get the point . im completely sure about the OG 1.130 . the problem is that now the hydrometer shows about 0.994 it means 18.5 alcohol(according to fermcalc) which is more than yeast's alcohol tolerance rate . so we shouldn't see fermentation any more but i can see the cap and co2 still comes out !! . i want to know how its posible?
some one told me that when alcohol level goes up in the wine hydrometer will show below 1 and its not accurate. is is right?
if so we must have a formula for correction of this fault as we have for temperature.

 

[Johnd]

thanks alot for your reply
there is not any problem yet .but i dont get the point . im completely sure about the OG 1.130 . the problem is that now the hydrometer shows about 0.994 it means 18.5 alcohol(according to fermcalc) which is more than yeast's alcohol tolerance rate . so we shouldn't see fermentation any more but i can see the cap and co2 still comes out !! . i want to know how its posible?
some one told me that when alcohol level goes up in the wine hydrometer will show below 1 and its not accurate. is is right?
if so we must have a formula for correction of this fault as we have for temperature.

As @jgmann67 and @salcoco said, it is entirely possible for EC 1118 to ferment to an ABV higher that 18%, you've obviously provided good conditions which have kept the yeast going strong all of the way until the finish line. It may go a tad lower, but you'll know it's done when your SG readings quit changing. The cap could still be forming as a result of the COI2 in the wine being coaxed out of solution by the presence of the skins, causing them to float. Follow the hydrometer, it will tell you when fermentation has ceased.

Refractometers lose their accuracy in the presence of alcohol, not hydrometers, you should trust what it's telling you. Freshly made wine rarely tastes wonderful, don't be fearful of the taste right now, it's in its infancy stages.

 

[Ajmassa]

some one told me that when alcohol level goes up in the wine hydrometer will show below 1 and its not accurate. is is right?

Maybe that could be their thoughts with the 'potential alcohol' part of the hydrometer ?
But I don't ever look at that anyway. Plugging in Starting SG and ending SG (as well as all the temps and hydromter calibrated temp) into FermCalc is pretty much the most accurate abv we can get.

 

[jgmann67]

some one told me that when alcohol level goes up in the wine hydrometer will show below 1 and its not accurate. is is right?

Anytime!

When I first started making wine (with kits - the process is simpler, but not much different), I read everything I could get my hands on. I think the best thing anyone can do is educate themselves. You do yourself the greatest favor by reading and absorbing as much material as you can about winemaking. Ask questions about what you learn and anything that's not clear to you.

There are plenty of posts on using a hydrometer and doing SG readings on this site and others.

 

[cpfan]

thanks alot for your reply
the problem is that now the hydrometer shows about 0.994 it means 18.5 alcohol(according to fermcalc) which is more than yeast's alcohol tolerance rate . so we shouldn't see fermentation any more but i can see the cap and co2 still comes out !! . i want to know how its posible?

The cap and CO2 do NOT mean that fermentation is very active. They mean that CO2 is coming out of solution. It is possible that fermentation is complete (or almost complete) as the .994 indicates, and CO2 is still coming out of solution. As already mentioned, the CO2 in the wine is affecting the taste.

Steve