What causes my wine to be bitter?

[mainshipfred]

If MLF is complete then it’s ok to add sorbate and Kmeta. If MLF is not complete the Kmeta will produce a geranium flavor.

Are you positive that's how it works. I thought the sorbate reacted with the lactic acid to cause it, I may have always misunderstood.

 

[Ohio Bob]

Malolactic fermentation in the presence of sorbate yields hexadienol, which produces the strong and disagreeable odor of rotting geraniums - an unfixable and highly undesirable outcome!
I'm not sure if an "absolute" filter will make a difference, these filters are expensive especially if there is no guarantee that t will work as you would like it to.

https://www.smartwinemaking.com/post/potassium-sorbate-vs-potassium-metabisulfite
The general recommendation is to add Kmeta after MLF is complete, usually a few weeks to a few months, depending on temperature. Then bulk age. Sorbate and Kmeta at bottling, especially if you back sweeten. I’ve seen sorbate advice that says it’s not needed if not back sweetening.

 

[berrycrush]

I would just let the wine age. Tanning, acid, tartness will all mellow out in time and they might give the wine a nice structure. No?

 

[winemaker81]

I was considering sweetening the wine after the tannin addition but it went through MLF. Wine conditioner has sorbate added so I'm afraid to add it. Glycerin might be considered though in my experience it takes quite a bit. I may try some bench trials using it.

You might consider glycerin to avoid a problem. Typically I add 1/2 to 1 oz glycerin per gallon of wine.

Search the forum before adding sorbate -- I know this has been discussed in detail in the last 6 months.

 

[sour_grapes]

If MLF is complete then it’s ok to add sorbate and Kmeta. If MLF is not complete the Kmeta will produce a geranium flavor.

Yeah, I believe you have that crossed. It is sorbate+MLF bacteria that can cause geraniums, not meta+MLF.

 

[Snafflebit]

I would just let the wine age. Tanning, acid, tartness will all mellow out in time and they might give the wine a nice structure. No?

I think that time will reduce the bitterness of my wine, but I have a 2016 Merlot that still tastes bitter, and as one presenter in the tannin videos says time probably will not fix bitterness. Unless I want to wait a decade, I suppose.

 

[tmcfadden932]

PVPP will take out bitterness.

 

[VinesnBines]

I would give some of the ideas a try. Maybe split up the batch and try different things on a small scale. I read this Fining Agents - The Australian Wine Research Institute before I tried egg whites on my troublesome 2020 PV batch. I didn't have bitterness per say; just no nose and a musty smell and taste at least on the back end. I was afraid to bottle without taking some steps to improve the nose and flavor. I was still not satisfied when I did bottle but it appears, the fining and time are making an improvement

I think the egg whites stripped a little color but I was willing to give up color rather than dump the batch.

I'd say give the pvpp a try. Glycerin can be added later if the pvpp fails or is not enough.

I was able to reduce the sourness of a red raspberry with calcium carbonate and back sweetening. My fig with bad VA is improving with lots of oak; I expect to back sweeten and maybe pop it in the attic over the summer to see if it oxidizes to a sherry style, I have little to lose.

 

[Snafflebit]

I have looked into PVPP. I read that the wine should be filtered afterward and I am NOT excited about buying a filter pack.

 

[Khristyjeff]

I just wanted to say this is an interesting string. I placed a WE Super Tuscan (Private Reserve-w/skins) in carboys on November 4th, '21 for aging and just sampled it. I was disappointed. Now, I have read that most red 'pasteurized' wine kits have an 'off-flavor' that can be strongly detected by some, and that by aging for 6-12 months (or longer) and bottling for another 4-6 months usually brings out the wine characteristics and leaves most of the bitterness behind. But having this wine still be 'extremely bitter' after 4 months, and especially a WE Luna Rosa bottled as per directions (still nowhere near good) in August 21, I'm beginning to wonder if adding some cellaring tannin or bottling tannin on these kits a month before bottling will help.

For what it's worth, the red FWK kits that I have crafted don't seem to have the issue. I believe someone else on here echoed this earlier on a separate thread.

And lastly, I did add some Vintner Wine Tannin to an Italian Nebbiolo juice last fall. It's coming along nicely, but truly just needs more age.

My experience so far: I have an RJS En Primeur Cab that tasted way sharp and kit taste at 6 months, then at 12 months tasted flabby so I thought I had ruined it. Oxidation? You can't fix that. But just left it alone. At 1-1/2 years it was a totally different wine. Very well balanced. Tasty.
I also have a Petite Pearl from grapes that after a year, an attempt at MLF and cold stabilizing, was still tart, almost sour. I asked on this forum and the response I got was "what's your hurry, it's only been 1 year. After 1-1/2 years it has begun to round out a bit so gives me some hope.
In my case I'm glad I didn't try to fix these early, because if it didn't improve, there would be no way of knowing if it failed because it was a loser all along or if it was my fix that screwed it up.
One of the best suggestions I've been following is from @winemaker81. He always suggests tasting wines at various stages and writing down your impressions. It's been a great way for me to learn the changes that wines go through over time.

 

[winemaker81]

One of the best suggestions I've been following is from @winemaker81. He always suggests tasting wines at various stages and writing down your impressions. It's been a great way for me to learn the changes that wines go through over time.

Cool! I'm happy that advice is useful.

A good example of this is my Oak Stix Experiment, in which I taste tested @Mike - Next Level Oak's oak products against oak cubes. The 4 wines went up-and-down during the 6 months of tasting, often in surprising ways. Several times during the test I thought one or more of the wines were tanking. We're now 6 months in the bottle and the wines are maturing very nicely.

 

[Snafflebit]

Now I am reading Scott Labs literature. They sell products with PVPP and casein, both of which are used to remove bitter phenols: Polycacel and Polycel. My local wine supply shop has several Scott products including Tannin Riche and maybe they have Polycel. According to Scott, the Polycel settles after a week and can be racked or filtered. Adding tannin is the easiest first step, I think.

 

[Larsen Cottrell]

My experience so far: I have an RJS En Primeur Cab that tasted way sharp and kit taste at 6 months, then at 12 months tasted flabby so I thought I had ruined it. Oxidation? You can't fix that. But just left it alone. At 1-1/2 years it was a totally different wine. Very well balanced. Tasty.
I also have a Petite Pearl from grapes that after a year, an attempt at MLF and cold stabilizing, was still tart, almost sour. I asked on this forum and the response I got was "what's your hurry, it's only been 1 year. After 1-1/2 years it has begun to round out a bit so gives me some hope.
In my case I'm glad I didn't try to fix these early, because if it didn't improve, there would be no way of knowing if it failed because it was a loser all along or if it was my fix that screwed it up.
One of the best suggestions I've been following is from @winemaker81. He always suggests tasting wines at various stages and writing down your impressions. It's been a great way for me to learn the changes that wines go through over time.

From my experience (a little over 2 years now) and almost 2000 bottles in, reds need time. Have a few left bottled late 2019, the early days of my wine making, WE French grape Cab and Ca Pinot Noir (the cheap kits!) and they are coming out great (by my taste), patience is a must with wine I have discovered.

 

[Snafflebit]

I have purchased some Tannin Riche and glycerine and performed bench trials. The results are surprising.

First, my local wine supplier carries several Scott Labs products, including PVPP based Polycel. I may try that to remove bitterness if the other options fail to deliver the desired results. The store owner is a winemaker also. He previously used Tannin Complex but has also switched to Tannin Riche for cellaring tannin, saying he likes the results. Scott Labs also sells a sample kit of tannins for $140. It is tempting to purchase the kit but it is probably overkill for my needs. I only purchased Tannin Riche and glycerine to experiment on my 2016 Merlot.

The case of merlot bottles that I have easily accessible to test, as it turns out, is not bitter! That leads me to believe I am tasting seed tannins in some bottles. I probably have free run and press fraction cases not labeled or mixed together. Anyway, I decided to test the effects of cellaring tannins on this "good" merlot. I poured 4 glasses of wine and added Tannin Riche at 150ppm, 100ppm, 50ppm and 0ppm. Blind tasting showed that the wine is improved by the addition at all these levels. The main change in the wine I noticed is that tannin removed an off-odor in the merlot that I did not notice was present until it was eliminated. Then I noticed a mid-palate development of tannin that is pleasant. The wine is very fruity and the tannin helped balance the fruit. Even at 150ppm we did not think the tannin was unpleasant or overpowering, but Tannin Riche (French oak based) has a slight maple-y odor at high concentration. Eventually I could tell the higher levels of tannin were beginning to affect my palate and we decided on 50ppm as a good level. Still, I do not believe the wine would be ruined by higher amounts. I would not say that perceived sweetness increased, but a more balanced wine resulted, and the wine tasted higher quality.

Next I tested the merlot at a glycerine concentration of 0.4 and 0.8 oz./gal. I noticed increased vicosity and increased sweetness, but at a level that required comparison bench trials to appreciate the change. The flavor improvement using glycerine is less pronounced and I am not yet able to tell how glycerine will affect bitterness.

My conclusion is that Tannin Riche and glycerine additions together can improve my wines and I will gladly use them in the future. If I can graduate to barrels from carboys, maybe tannin additions will become unneccessary. I am very surprised by the elimination of off-odor. I am uncertain of the cause of this odor, it was slight. I will hazard a guess that it is mercaptan, maybe from extended lee contact.

 

[winemaker81]

I have purchased some Tannin Riche and glycerine and performed bench trials. The results are surprising.

Thanks for the detailed description.

 

[mainshipfred]

I have purchased some Tannin Riche and glycerine and performed bench trials. The results are surprising.

First, my local wine supplier carries several Scott Labs products, including PVPP based Polycel. I may try that to remove bitterness if the other options fail to deliver the desired results. The store owner is a winemaker also. He previously used Tannin Complex but has also switched to Tannin Riche for cellaring tannin, saying he likes the results. Scott Labs also sells a sample kit of tannins for $140. It is tempting to purchase the kit but it is probably overkill for my needs. I only purchased Tannin Riche and glycerine to experiment on my 2016 Merlot.

The case of merlot bottles that I have easily accessible to test, as it turns out, is not bitter! That leads me to believe I am tasting seed tannins in some bottles. I probably have free run and press fraction cases not labeled or mixed together. Anyway, I decided to test the effects of cellaring tannins on this "good" merlot. I poured 4 glasses of wine and added Tannin Riche at 150ppm, 100ppm, 50ppm and 0ppm. Blind tasting showed that the wine is improved by the addition at all these levels. The main change in the wine I noticed is that tannin removed an off-odor in the merlot that I did not notice was present until it was eliminated. Then I noticed a mid-palate development of tannin that is pleasant. The wine is very fruity and the tannin helped balance the fruit. Even at 150ppm we did not think the tannin was unpleasant or overpowering, but Tannin Riche (French oak based) has a slight maple-y odor at high concentration. Eventually I could tell the higher levels of tannin were beginning to affect my palate and we decided on 50ppm as a good level. Still, I do not believe the wine would be ruined by higher amounts. I would not say that perceived sweetness increased, but a more balanced wine resulted, and the wine tasted higher quality.

Next I tested the merlot at a glycerine concentration of 0.4 and 0.8 oz./gal. I noticed increased vicosity and increased sweetness, but at a level that required comparison bench trials to appreciate the change. The flavor improvement using glycerine is less pronounced and I am not yet able to tell how glycerine will affect bitterness.

My conclusion is that Tannin Riche and glycerine additions together can improve my wines and I will gladly use them in the future. If I can graduate to barrels from carboys, maybe tannin additions will become unneccessary. I am very surprised by the elimination of off-odor. I am uncertain of the cause of this odor, it was slight. I will hazard a guess that it is mercaptan, maybe from extended lee contact.

I think our findings were pretty much the same even though we used different but similar products. It was a toss up for me whether to use 75 or 100 ppm. I ended up using 100 ppm. My thought was it could possibly tame down with some additional aging. I'll play with glycerin prior to bottling since it doesn't require a waiting period. This whole thread has been very informative so thanks for posting.

 

[VinesnBines]

Fred or anyone that would like to share the cost of Tannin Riche, I’m game. It looks like ordering may be limited to large quantities. I’m intrigued by your findings. I hadn’t thought of finishing tannins.

 

[Ohio Bob]

Morewine.com sells an 18g packet of the Riche for $16.99. I placed an order for it yesterday.

 

[mainshipfred]

Morewine.com sells an 18g packet of the Riche for $16.99. I placed an order for it yesterday.

Bob, I believe Morewine only has Roche Extra which is derived from American oak, Riche is French oak.

 

[Ohio Bob]

You are correct, I ordered the Extra, but didn’t write Extra. I should be more extra careful to write what I think.