Why do some wines take longer?

[HankRearden]

I'm currently making my second batch of "Welch's" Wine.

Way better this time, thanks to the help on this board. I switched out Montrachet for K1-V1116 and added nutrients and so far no H2S odor!

But one thing I noticed in common was that they are both REALLY speedy.
This went from 1.102 to 1.013 in 4 days!
The last batch was about the same and finished in 14 days.
At that point it was at about .994, still bubbling and fairly dry (I back-sweetened with 1/2 cup sugar per gallon and even then it wasn't too sweet) It was strong.
I expect this batch to finish just as quickly.

BUT...
I just picked up a Cru kit that requires 4 weeks to finish.
There was another yeast variety in the box (forgot which).
Could that be the reason?

It seems like the other variables are immovable. If the concentrate in the kit has less sugar, there will be less alcohol. So that can't be a factor, can it?

Could Tannins slow the process?
Could my other batch have gone longer? If so, wouldn't it have been TOO dry? It was plenty strong.

Help me understand.
Thanks in advance!

 

[vernsgal]

The kits count the racks as time. So if it says 4 weeks -that's not how long it takes to ferment but how long, or soon ,until you can bottle.
My opinion is , you don't want to ferment too quickly or you lose some of the flavors. If you're fermenting quick, check your temp. it might be too high.
My kits usually take about 10 days to be sure they're dry.To be sure your batch is dry, the SG should remain the same for 3 consecutive days.(also try and keep the temp the same or close for fermenting days)

 

[salcoco]

granted the amount of sugar will determine fermentation time, but also the temperature of must, ambient temp, the type of yeast and the amount of nutrients in the juice or added will also affect fermentation time.

 

[montanaWineGuy]

My apple and Rhubarb wine is fast. Blueberry, Oregon Grapes, and Elderberry wine takes much longer, 2 times longer almost.

 

[HankRearden]

The kits count the racks as time. So if it says 4 weeks -that's not how long it takes to ferment but how long, or soon ,until you can bottle.
My opinion is , you don't want to ferment too quickly or you lose some of the flavors. If you're fermenting quick, check your temp. it might be too high.
My kits usually take about 10 days to be sure they're dry.To be sure your batch is dry, the SG should remain the same for 3 consecutive days.(also try and keep the temp the same or close for fermenting days)

Thanks all.

So now I'm understanding that the end of fermentation is not equal to "ready to bottle". Is that correct?

Also, it seems that though my SG was at about the end, the continued bubbling probably meant that it could get drier but probably a small amount until the end of fermentation.
In my case, if I had let it go another 2 - 3 weeks, it probably would not have gotten significantly drier, but would have settled and produced better flavors.

Am I starting to get the picture?

 

[David219]

Yes, in part.
Fermentation produces both alcohol and carbon dioxide. The wine will continue to blow off the CO2 ("bubbling") for quite some time after fermentation is complete. Activity in the air lock is not always an indicator of active fermentation.
The longer a wine is allowed to rest after fermentation is complete, the clearer and stiller (less bubbly) it will be.

 

[vernsgal]

In your kit instructions it will probably show you to rack in 6-8 days and then again at day 20.
That is when they are suggesting your wine is now dry.You can start checking the SG about day 12 and when you go 3 consecutive days at the same you should be done ferment. Then it's time to degas (unless you are going to allow it to degas naturally by leaving it sit a few months)You can do that with a drill and attachment or with a spoon(real hard with a spoon). Next step would be your clearing agents (Kieselsol and chitosan)
After adding your clearing agents allow your wine to sit for 2 weeks then rack off sediment(lees)
Your wine should now be clear. If you degassed you could now bottle and age for minimum 3 months.( I always go 6 at least)*Never bottle fizzy wine! you could end up with corks blowing
Some people think if a kit says 4-6 weeks that its ready in that time, but that is the minimum time for bottling.Then you must play the waiting game and allow it to age

 

[Scooter68]

Speed of fermentation is a result of a number of things including, but not limited to, the yeast, the temperature, the acidity, and the starting SG. Obviously a very active fermentation of a lower starting SG will finish faster than a higher starting SG, IF everything else is equal.
There are very few absolutes to our wine making, since natural fruits can very so much in the sugars, acidity and so many other things, THEN you add in the yeast types, temperature etc.

What is more reliable is the guidance for fermentation temperatures and yeast types. White or lighter colored wines tend to lose their volatile components faster at higher fermentation temps so they do best fermenting at a lower temperatures. Red or darker wines aren't as likely to lose the 'essences' or volatile components as quickly perhaps because they are more concentrated in those types of wines.

And like the broken record ... above all patience always pays big dividends.

 

[BernardSmith]

But importantly, IMO, it's not that some wines finish faster than others, it's that the wine maker either by commission or omission is not controlling the speed of the fermentation. I say this because Claude Jolicoeur, the Canadian cider maker, refers to fermentations he monitors where the gravity drops by .001 of a point each day while in the secondary and if my memory serves me, drops about 8 points over 50 days in the primary. The more vigorous the fermentation, the more you are likely to lose volatile flavor, aroma and color molecules