Front loading excess sugar

[Earldw]

Good day everyone. I made a blackberry all-juice wine last summer and I’m about to put it in the bottle. Initial SG was 1.103, final SG 0.994. It is very dry with no noticeable sweetness though it is pleasant and quite drinkable. When I experimented with backsweetening I always ended up with something that tasted unnatural and seemed to highlight some sharpness and the alcohol. I’ve decided to leave it dry.
I am also about to get a big harvest of spring blackberries so I’m wondering if I add enough sugar to get initial SG up around 1.110 given the same yeast if I could expect more residual sugar in the finished wine or just more alcohol?

 

[BigDaveK]

This is an area that I've been wrestling with for a couple months and it all has to do with the hydrometer measuring density, not sugar content. What I've been doing is checking on line for the average sugar content of my fruit and then measuring SG AND Brix prior to sugar addition and comparing. Sometimes they're close, sometimes way off. My most extreme example was the ground cherries. The SG came in at 1.060, they weren't that sweet, and I found out they have sugar alcohols rather than fermentable sugar. I started 3 wines around 1.140-1.145 that fermented to .990 and the alcohol wasn't noticeable. There's no way 71B went to 19% abv. Without some serious testing we home wine makers make educated guesses and do the best we can. I know I'm not much help, sorry.

I agree with you on one point, though - I had 2 wines with residual sugar, the leftover sugar is probably fructose, and I really liked the flavor!

 

[vinny]

When I experimented with backsweetening I always ended up with something that tasted unnatural and seemed to highlight some sharpness and the alcohol. I’ve decided to leave it dry.

Just curious if you tasted everything immediately or gave it some time. I know sugar blends and a wine tastes way different after some time. Not sure if shock is the right word, but it might explain why it tasted out of balance, just needed some time to mellow?

 

[BigDaveK]

Just curious if you tasted everything immediately or gave it some time. I know sugar blends and a wine tastes way different after some time. Not sure if shock is the right word, but it might explain why it tasted out of balance, just needed some time to mellow?

Good point (that slipped my mind!) and I totally agree. While the residual sugar tastes great immediately, back sweetening needs time. I wonder if with the acid in the wine the sucrose breaks down into glucose and fructose? Where's that @Rice_Guy when you need him?

 

[sour_grapes]

I wonder if with the acid in the wine the sucrose breaks down into glucose and fructose?

This has long been my contention.

 

[sour_grapes]

I took a gander, and found this:

A simple syrup solution has an important advantage, as I will explain. Let's talk sweetness. You often read here that people who backsweeten their wine find that they "overshoot," and the wine is too sweet. I believe what happens is that they add table sugar (aka sucrose), and taste the wine, and then stop when it tastes sweet enough. However, table sugar, which is a disaccharide, eventually separates into fructose and glucose molecules. Fructose is much sweeter than table sugar.
When you make simple syrup, you efficiently break up the sucrose into fructose and glucose. Thus, simple syrup is already as sweet as it will get, so your taste testing will be indicative of the final product. (Add a little lemon juice when making the simple syrup to facilitate breaking the sucrose up.)

 

[BigDaveK]

This has long been my contention.

I think so, too.

Found a mention on a cooking site that said heating while making simple syrup will break the sugar down. They weren't making invert sugar. Wish I could find something "official" though.

 

[Raptor99]

An invert sugar requires a much longer cooking period than making simple sugar.

I wonder if with the acid in the wine the sucrose breaks down into glucose and fructose?

I don't think that the acid has anything to do with it. Saccharomyces cerevisiae produce the enzyme invertase, which breaks down sucrose into glucose + fructose.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001122https://www.researchgate.net/publication/315831468_Invertase_Production_by_Saccharomyces_cerevisiae
BTW, as usual we have gotten way off track from the OP!

 

[BigDaveK]

I don't think that the acid has anything to do with it. Saccharomyces cerevisiae produce the enzyme invertase, which breaks down sucrose into glucose + fructose.

Yeah, I know about invertase. I was grasping for ideas. The sweetness of my back sweetened with syrup wines changes over time. At least that's my perception.

BTW, as usual we have gotten way off track from the OP!

I thought going off topic was an unspoken rule.

 

[Rice_Guy]

* It makes sense that there is break down of sucrose, pH/ concentration of hydronium ions pushes the hydrolysis of sucrose.

wonder if with the acid in the wine the sucrose breaks down into glucose and fructose

The question has to be what is the reaction rate at room temp ,,, or at 10C (50F) in your cellar. The general model on kinetics is that reactions happen twice as fast for every 10C increase. With this we can guess that in one day at room temp. it will reach steady state.
* I have not seen anything / been looking for reaction rate kinetics.
If we use a months long time frame there are a few web references and traditional storage recipes which suggest that acids combine with alcohol to produce an ester and decrease the titratable acidity. (est. 0.1% per year)
* this is blackberry which has astringent polyphenols, you should expect that polyphenols will increase astringent (magnifies acids) notes when 18 to 24 months old and after that the polyphenols precipitate which results in higher sweet notes.

* back to the OP, ,, for home wine making we don’t have good tools which let us accurately stop a fermentation at 1.000 or 1.010 or even bone dry at .990. What you get for residual sugar after fermentation will be more random. Our reliable way to put sweetness into a finished wine is back sweetening. ,,, BUT if we are planning on year long storage of a few bottles we should add more acid to those.

 

[winemanden]

Yeah, I know about invertase. I was grasping for ideas. The sweetness of my back sweetened with syrup wines changes over time. At least that's my perception.

I thought going off topic was an unspoken rule.

I think the sweetness changes, and acid and tannins changes, are just the result of wine ameliorating as it matures. Even after a few days, the wine tastes a bit less sweet. It may be subtle, but the difference is there.
Using Fructose instead of white sugar is a great way of back sweetening. It is more expensive, even though you need less of it.
Anyway, all this talk about using sugar, does somebody work for a sugar corporation?

 

[Hazelemere]

Good day everyone. I made a blackberry all-juice wine last summer and I’m about to put it in the bottle. Initial SG was 1.103, final SG 0.994. It is very dry with no noticeable sweetness though it is pleasant and quite drinkable. When I experimented with backsweetening I always ended up with something that tasted unnatural and seemed to highlight some sharpness and the alcohol. I’ve decided to leave it dry.
I am also about to get a big harvest of spring blackberries so I’m wondering if I add enough sugar to get initial SG up around 1.110 given the same yeast if I could expect more residual sugar in the finished wine or just more alcohol?

just more alcohol

 

[Earldw]

Just curious if you tasted everything immediately or gave it some time. I know sugar blends and a wine tastes way different after some time. Not sure if shock is the right word, but it might explain why it tasted out of balance, just needed some time to mellow?

You make a valid point Vinny and I think I’ll sweeten up a couple of bottles to different levels and let them bottle age. But the next Batch will be starting in less than a month……

 

[Earldw]

* It makes sense that there is break down of sucrose, pH/ concentration of hydronium ions pushes the hydrolysis of sucrose.

The question has to be what is the reaction rate at room temp ,,, or at 10C (50F) in your cellar. The general model on kinetics is that reactions happen twice as fast for every 10C increase. With this we can guess that in one day at room temp. it will reach steady state.
* I have not seen anything / been looking for reaction rate kinetics.
If we use a months long time frame there are a few web references and traditional storage recipes which suggest that acids combine with alcohol to produce an ester and decrease the titratable acidity. (est. 0.1% per year)
* this is blackberry which has astringent polyphenols, you should expect that polyphenols will increase astringent (magnifies acids) notes when 18 to 24 months old and after that the polyphenols precipitate which results in higher sweet notes.

* back to the OP, ,, for home wine making we don’t have good tools which let us accurately stop a fermentation at 1.000 or 1.010 or even bone dry at .990. What you get for residual sugar after fermentation will be more random. Our reliable way to put sweetness into a finished wine is back sweetening. ,,, BUT if we are planning on year long storage of a few bottles we should add more acid to those.

I guess I was thinking that as the alcohol rises the yeast will naturally die off before all of the sugar is consumed. Is there that much variation in a specific yeast strains alcohol tolerance? The result would be high alcohol and sweet right?

 

[Jovimaple]

I guess I was thinking that as the alcohol rises the yeast will naturally die off before all of the sugar is consumed. Is there that much variation in a specific yeast strains alcohol tolerance? The result would be high alcohol and sweet right?

Tolerance is a range, and it's up to the individual yeastie beasties to decide when they are done.

If it were me, I would stick with fermenting to dry and then back sweetening to the desired level of sweetness. I like the control that process gives me, rather than leaving it to chance and possibly ruining the batch or having to blend with another to make it drinkable.

But it's your wine, so give it a shot if the risk is acceptable to you!

 

[winemaker81]

I guess I was thinking that as the alcohol rises the yeast will naturally die off before all of the sugar is consumed. Is there that much variation in a specific yeast strains alcohol tolerance? The result would be high alcohol and sweet right?

Adding on to what Joni said, wine yeast strains range in tolerance from 10% to 18%, and those ranges are laboratory test results. In your home, one batch might exceed the lab rating while another will be less. Trying to get the yeast to die off when you want doesn't work well, and it's most likely to result in high ABV wines.

Regarding backsweetening, bulk age 9 months so the yeast is dead, then backsweeten lightly with juice and sugar.

 

[sour_grapes]

I agree with the others, but if you want to explore this method, here is a good thread from @jswordy that you could glean some info from.

 

[sour_grapes]

I agree with the others, but if you want to explore this method, here is a good thread from @jswordy that you could glean some info from.

I don't know what happened, but the link was not here this morning. Here is the thread:
Welch's concord with the super-sugar method

 

[Earldw]

I don't know what happened, but the link was not here this morning. Here is the thread:
Welch's concord with the super-sugar method

Pretty much what I was thinking with a lot more detail; thanks Paul.

 

[BigDaveK]

@Earldw , two things:

First, the RC212 mentioned in the thread looks like 16% not 12% from what I've read.

Second, older recipes often varied the amount of sugar at the beginning depending on the wine to be made. I was always curious about the process so I finally tried it a couple weeks ago. Planning a sweet wine I did a dandelion with 71B (14%) and had the OG at 1.120. Last time I checked I'm really close to 1.000 and it's still slowly chugging along. I'm almost 2% over the 71B tolerance so far. I'm still curious about the process but I'll have to find a yeast with a lower alcohol tolerance before I try it again. Maybe I'll try a beer yeast or a - gasp! - bread yeast.