WineXpert Chaptilization

[David219]

I'm starting my third WE chocolate raspberry port kit. The first attempt suffered from a stalled fermentation. My second go around, I tried to add the sugar a little sooner than the instructions recommended...while the yeast were still seemingly more actively working, gauged by the hydrometer readings and just the visible "fizzing". It still stalled, but got further along than the first attempt.

My questions: what is the science/biology/chemistry behind chaptilization, other than more sugar=more alcohol? Why can't the sugar just be added up front at the start? Is there harm in adding it earlier in the fermentation process than recommended? Is there an issue with osmolarity, or something, where the sugar concentration is too high for the yeast cells to tolerate if the sugar is added up front or earlier in the process?

Thanks for your help/advice!

 

[heatherd]

Here is a good article on chapitalization.
http://winemakermag.com/371-how-sweet-it-is-chaptalization

I am guessing that your prior batch may have stalled due to exceeding the limits of the yeast in terms of alcohol tolerance, perhaps?

If so, my suggestion would be to add less sugar or get a more tolerant yeast. I have made these kits without issue, so you should also be able to make them without stalling.

Heather

 

[sour_grapes]

But, yes, your suspicions are correct: If you raise the sugar content too high at the start, your yeast will not be able to handle it.

 

[Dhaynes]

I've also read that dividing the sugar into thirds and adding one third at a time with a day or two in between helps because it keeps the increase in the sugar level smaller. Apparently this is easier on the yeast. Another side benefit is that if it gets stuck on the first or second addition there is less left over sugar.

Other things that are suppose to help is stirring or rocking the carboy one or more times a day towards the end to try to get rid of some of the CO2 which is also hard on the yeast and maintaining a constant temperature that is a little on the high side. Basically I think what is going on is that this kit pushes the yeast to the limit. Little things that don't matter much in a medium ABV wine can be enough to stall or kill the yeast when it is struggling in a high alcohol environment. You need to give the yeast every advantage possible to survive.

 

[David219]

By my calculations, at the starting SG of 1.128 for this kit, fermenting to dry without any sugar addition would yield an alcohol content @18%. This is right at the limit of the supplied premier cuvée...or probably any yeast.

Is the yeast even able to eat ANY of the added sugar with chaptilization? Or are we basically just sweetening the wine? Is it better to add it near the end of fermentation, as directed, letting the yeast run their normal life-cycle course with the available sugar already in the must, if they aren't going to be able to eat the additional sugar anyway? I'm wondering if this is even chaptilization in the truest sense of the word...

 

[richmke]

The calculator I use shows 1.128 -> 0.996 is 17.3% ABV.

Adding sugar to raise the SG by 0.010 raises the ABV to 18.64%

I would let it ferment down to 1.000
add sugar (as simple syrup) to raise the SG by 0.002
Stir to release CO2 and mix in the sugar
let it ferment down to 1.000
repeat until the yeast gives up.

 

[wineh]

I don't make this style of kit, but with high SG musts, you should ensure that you get the temperature at the high end of the recommended rage, but don't let it get too hot. does that make sense?

 

[Just-a-Guy]

I've also read that dividing the sugar into thirds and adding one third at a time with a day or two in between helps because it keeps the increase in the sugar level smaller. Apparently this is easier on the yeast. Another side benefit is that if it gets stuck on the first or second addition there is less left over sugar.

Please forgive my lack of knowledge (and I am not doing kits, just fruit wines, so maybe I shouldn't even be here). But when you do this, add sugar along the way, how can you determine final ABV? The only way I know to do it is use the starting SG and the final SG and calculate.

JAG

 

[richmke]

Please forgive my lack of knowledge (and I am not doing kits, just fruit wines, so maybe I shouldn't even be here). But when you do this, add sugar along the way, how can you determine final ABV?

First way:

Part 1: Assume Starting SG of 1.100, and ending SG of 1.000. That is a change of 0.100 SG, and you can calculate the ABV.

Part 2: Let's say you ferment down to 1.010, and add sugar. After you add sugar, the SG is 1.020, that means you added 0.010 of SG. So, the new change of SG is 0.100 plus 0.010 for a total of 0.110, and you can calculate the ABV.

Second way:

Same Part 1.

In Part 2, use a sugar calculator to estimate the SG of x cups or pounds of sugar when you add it to y gallons of must. Add that to Part 1 and calculate the ABV.

 

[buzzzkllr]

Thanks for the link to Chaptilization. Finally I read something that sank in. I guess I'm just getting fuzzy from all the reading. I usually just follow the recipe but now I'm getting ready to attempt to adjust the alcohol but adding sugar to raise my SG. I think I finally understand. Trial and error, right. My question is.... my recipe calls for half the sugar at the beginning and half the sugar after the first racking into the carboy. At this point does this sugar still turn to alcohol or is it just a sweetener since the main fermentation (or all) has stopped. I usually get the SG to 1.0 (7days or so) before I transfer it to the carboy. I'm thinking it's still going to turn to alcohol but I want to be sure. Thanks for any help.

 

[Dhaynes]

If you are talking about the Chocolate Raspberry Port, you may want to rack this a little sooner say 1.010 or so. Keep in mind that the danger with this kit is that you are pushing the yeast to their limit. I've read that racking the wine also places some stress on the yeast. Therefore it is better to rack this wine before the alcohol level gets too high. I can't swear to it. I just read it somewhere while researching problems with this kit. When I make this kit again that's what I plan to do. That and splitting the sugar addition up into three small doses.


Sent from my iPad using Wine Making

 

[David219]

What I did/am doing is this:

1. Used a brew belt to keep temp steady at 76 degrees.
2. Added 1.5 grams of Fermaid K at the start of fermentation
3. Stirred must daily, checking SG once or twice a day.

When the SG reached 1.022, I added enough Dextrose (about 60% of the supplied amount) to bump the SG 0.010 to 1.032.

The instructions call to rack when the SG is below 1.018, expecting the fermentation to continue to around 1.010 at which point the f pack is added.

The issue you raised is a concern for me. My first attempt at this kit stalled at the racking. Last night, the SG was 1.022. I plan on letting it ferment down closer to the desired final SG. Then when I rack, if fermentation stops, it's not such a big deal. If it doesn't, even better.

My starting SG was 1.128. If it ferments to 1.010 in the primary, factoring in the 0.010 dextrose addition, the alcohol content will be around 17.4%. The premier cuvée can supposedly produce/tolerate 18%. We'll see what happens.