Two different final sg from the same must

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Kivanc

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Recently I have fermented 7 liters of berry tea wine. I used two bottles. I started at 1120. The second bottle was half filled. The second finished at 1020, a week ago. Yesterday the must in the first bottle finished fermenting at 1040. I didn’t do transferring during fermentation. I wonder why I come up with these strange results.
 
And are you certain they have stopped fermenting?
Those SG's sound a little high to be finished. One batch fermented in a 1 gallon bottle that was almost full? The other fermented in a 1 gallon bottle that was about half full? You didn't do the fermenting in a single primary bucket? Is that all correct?
 
I took it and measured again, it still point at 1040 (didn’t use campden tablets). I’ve already consumed the wine in the half full bottle. I put the must in primary for a week. Yes, one was almost full, the other was half full. Those two bottles fermented at the same temp conditions through primary. I did do the fermenting in a single primary bucket. I used a 15% tolerated yeast. The temperature was probably 28-30 degree. I am sure they have finished fermenting.
 
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I took it and measured again, it still point at 1040 (didn’t use campden tablets). I’ve already consumed the wine in the half full bottle. I put the must in primary for a week. Yes, one was almost full, the other was half full. Those two bottles fermented at the same temp conditions through primary. I did do the fermenting in a single primary bucket. I used a 15% tolerated yeast. The temperature was probably 28-30 degree. I am sure they have finished fermenting.

Was it very sweet when you drank it?

And what made you sure that they finished fermenting?
 
They are obviously sweet but not too sweet. I personally choose to begin with at higher levels to come up with sweet wines. The last one I bottled is 10,5% of alc. The half filled secondary finished early but it had 13,12% of alc.

Because I gave them a one more week when I decided the bubbling inside the tube is ceased.
 
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They are obviously sweet but not too sweet.
Well, not obvious to us. The question @sour_grapes asked about sweetness was possibly to confirm your SG reading. Many less-experienced wine-makers will mistake 1.040 for 1.004. They are very different, and caused a lot of confusion in a recent thread, where the member reported 1.080 when it was actually 1.008.
Because I gave them a one more week when I decided the bubbling inside the tube is ceased.
We usually say "finished fermenting" to mean "fermented dry." To me, your fermentation is not finished, it is "stuck" or "stalled." The high SG and sweetness indicate there is still food (sugar) for the yeast, but some other condition is preventing it from multiplying, in your case probably the alcohol concentration or lack of oxygen, or both. Air lock bubbling is not a reliable way to determine the state of fermentation, only SG readings are. It is a good thing you drink this quickly, since bottling it now and aging it would risk popping corks or exploding bottles.

The half full bottle possibly fermented quicker because of the much larger surface area for the yeast to obtain oxygen. Most people will not put wine into secondary at such high SG for this reason. Now, if the SG is really 1.004... that's a different story. But from your description of the sweetness, I trust you reading is accurate.
 
Thanks.

Guess I would do transferring during secondary to take the SG to adequated levels or below zero.

My second question is that does dry wine has certain effects on alcohol durability? What are the benefits of “dry fermented” wine?
 
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Thanks.

Guess I would do transferring during secondary to take the SG to adequated levels or below zero.

My second question is that does dry wine has certain effects on alcohol durability? What are the benefits of “dry fermented” wine?

Oh, the only concern is that, if the wine still has sugars in it, fermentation could restart after you bottle it. The so-called "bottle bombs."
 
Thanks.

Guess I would do transferring during secondary to take the SG to adequated levels or below zero.

My second question is that does dry wine has certain effects on alcohol durability? What are the benefits of “dry fermented” wine?
It sounds like you got interested in tea wine from a recipe then started adding more sugar in the primary to make it sweeter.
You should spend some time in the Skeeter Pee forum, the Country Fruit Winemaking forum, and/or the DangerDave's Dragon Blood Wine thread. There is a wealth of information there about making interesting and often inexpensive wine, and how and why to backsweeten properly.

Very basically, you only start with enough sugar to get the alcohol level you want and that your yeast can handle. You ferment it until dry, which makes it very easy to tell when all of the yeast is dead and the sugar is completely gone. Then you stabilize it to prevent possible refermentation, and let it clear. Take the clear wine and add as much sugar and/or other flavours to your taste. Wait a while to make sure it doesn’t start fermenting again, and then bottle it.
 
The half full bottle possibly fermented quicker because of the much larger surface area for the yeast to obtain oxygen.

Does this situation about yeast having oxygen to ferment quicker is normal? Can I combine the two bottles in one bottle? For example, the reading of the filled bottle is 1040, and the reading of the half filled bottle is 1030. The average of these are 1.035 sg; Can I make this kind of calculation and combine them in one 10 liter bottle?
 
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* if they taste OK I would mix them, if there is an off flavor I would not
* your OP is in July, four months, my guideline for considering yeast dead/ it is ”safe”, is nine months old. The potential risk is similar to back sweetening where the yeast start again.
* the OP asked what happened? I look at wine as a “multi variable preservation system”. Since the volumes were different my guess would have been one of the traits causing preservation was out of balance with the other, ex oxygen or even campden dosage rate. , , result it is stuck and fermentation is finished (preservation). we were at guessing what that tipping point was. I would expect it to be disrupted by mixing, but if the yeast have starved off it doesn’t matter.
 
Excuse me, I have to say this is my other blackberry tea wine which I started to ferment at 1120 sg on Oct 9. On secondary fermentation I had to separate them in two different sized bottles. And I had similar result. I read 1040 and 1030 from different volumes while the two bottles were fermenting. I actually racked the two bottles in one 10 liter bottle with leaving 3.54 inches of headspace. The water in airlock is still active which it is producing foam and I can hear the fizzling sound.

Thank you for the reply for leading me in right direction.
 
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Does this situation about yeast having oxygen to ferment quicker is normal?
Yes, yeast needs oxygen to reproduce. I recently read an article posted by @stickman that was VERY interesting reading:
https://www.winemakingtalk.com/attachments/oxyfer09-pdf.67792/
Can I combine the two bottles in one bottle?
Of course. In primary, it's best to have everything in one bucket, but you can split it up if necessary. In secondary, use as many vessels as necessary to limit the headspace above the wine. The smaller the volume and the smaller the surface area of wine exposed to it is, the less oxygen will be available to oxidize the fruit and/or alcohol. In secondary the yeast doesn't need to reproduce any more, so removing oxygen is good. Leave enough headspace that any foam being produced does not push through the air lock and make a mess.

For example, the reading of the filled bottle is 1040, and the reading of the half filled bottle is 1030. The average of these are 1.035 sg; Can I make this kind of calculation and combine them in one 10 liter bottle?
Your math is incorrect because you have twice as much wine at 1.040. The correct average is [ (1 bottle * 1.040) + (0.5 bottle * 1.030) ] / 1.5 bottles total = 1.037. But I see no need to bother calculating that. Of course you can combine them, in fact it is advisable to reduce the headspace. But only put into secondary once the fermentation has slowed to just bubbles (like soda in a glass), and producing no foam. We usually go by SG, but your excessive initial sugar concentration makes SG a poor indicator of yeast activity.

I see many recipes that describe the same method of fermenting wine as you are using. In other words: start with excessive sugar, ferment until yeast stops on its own or attempt to stop manually at a given SG to provide residual sweetness. In my opinion, that introduces more variables and uncertainties than necessary. As you have indicated, you have no way to know ahead of time how much sugar you are going to be left with after fermentation. You also run the risk of the wine starting to ferment again at a later time, even though you think it's finished.

See my post above if you want a method that produces more consistent, and more controllable results.
You should spend some time in the Skeeter Pee forum, the Country Fruit Winemaking forum, and/or the DangerDave's Dragon Blood Wine thread. There is a wealth of information there about making interesting and often inexpensive wine, and how and why to backsweeten properly.

Very basically, you only start with enough sugar to get the alcohol level you want and that your yeast can handle. You ferment it until dry, which makes it very easy to tell when all of the yeast is dead and the sugar is completely gone. Then you stabilize it to prevent possible refermentation, and let it clear. Take the clear wine and add as much sugar and/or other flavours to your taste. Wait a while to make sure it doesn’t start fermenting again, and then bottle it.
Note that I neglected to mention the importance of adding potassium sorbate when back-sweetening.
 

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