some oxidation in my Riesling batch

[JohnBurns]

First, I appreciate this forum and read it all the time. Now I have brownish color in my 5 gallon carboys of Riesling. I noticed air being mixed with the wine when racking. I took the pump apart, cleaned the diaphragm and the pump is good now but the wine is still brown and not clear after 3 months, additional racking, and using Super Kleer. Taste is young and not awful. Any suggestions? Thanks

 

[Johnd]

First, I appreciate this forum and read it all the time. Now I have brownish color in my 5 gallon carboys of Riesling. I noticed air being mixed with the wine when racking. I took the pump apart, cleaned the diaphragm and the pump is good now but the wine is still brown and not clear after 3 months, additional racking, and using Super Kleer. Taste is young and not awful. Any suggestions? Thanks

There's not much that you can do with wine once it's got some oxidation, if it's still decent to drink, not much harm done. Getting it cleared well may help a bit with the color, and perhaps even the taste, so continue on that course.

We already know that white wines are more prone to oxidize, but I wouldn't imagine that some oxygen exposure in just one racking would have such ill effects if your sulfite protocol is proper, the sulfite will scavenge all of the oxygen out of the wine and continue to protect it as long as the levels are sufficient. Make sure your sulfite levels are proper in the remaining wine and keep up with them until you ultimately get the wine cleared and bottled.

Use the chart below to help you with the proper sulfite additions, based on pH, and make sure to use the curve for white wine at .8 mg/L molecular level.
http://blog.juicegrape.com/wp-content/uploads/2019/11/SO2MF1.gif

 

[JohnBurns]

Thank you. PH is 3.03 and I added 1/4 tsp Kmeta per carboy so I think I'm ok. I plan to try another round of Super Kleer. Is that a good idea vs. just continue to wait for it to clear?

 

[Johnd]

Thank you. PH is 3.03 and I added 1/4 tsp Kmeta per carboy so I think I'm ok. I plan to try another round of Super Kleer. Is that a good idea vs. just continue to wait for it to clear?

Too much fining can strip some flavor compounds from wine, as well as color, so try to avoid over fining your wine. In your case, with a bit of browning, some color stripping might not be a bad thing, as long as the flavor isn't at risk as well.

Personally, my belief is that time is the best way to clear wine, and it'll clear on its own unless you have a pectin or protein instability problem. If your wine is given the time to release all of the CO2 from fermentation, the clearing process usually follows pretty quickly. Keep your wine topped up to within 3/4" or so from the bung, use and airlock so gas can get out, maintain sulfite levels, and keep the wine in the mid 70's, and you'll have put yourself in a good spot for clearing.

Just curious, how long ago did you complete fermentation?

 

[JohnBurns]

Fermentation in January

 

[JohnBurns]

A little more detail; the wine finished fermentation 1/25 which was the racking that introduced air. Racked again 3/7 and cold stabilized 3/11 to 3/20. Racked cold and then fined on 5/20 and racked 5/27. Racked again 7/12 and 7/31. Added 1/4 tsp Kmeta at racking and pics are from today.

 

[Cynewulf]

A little more detail; the wine finished fermentation 1/25 which was the racking that introduced air. Racked again 3/7 and cold stabilized 3/11 to 3/20. Racked cold and then fined on 5/20 and racked 5/27. Racked again 7/12 and 7/31. Added 1/4 tsp Kmeta at racking and pics are from today. View attachment 77166View attachment 77166

That’s a lot of rackings.

 

[winemaker81]

Yeah, that's a lot of rackings. Given that the wine has been cold stabilized and fined, the color is not good. How many rackings were performed with the pump inserting air? Just the one? I agree with @Johnd that a single racking should not could introduce that much oxidation, but something did. How long did you leave the wine in the primary after fermentation completed?

I can't offer other advice other than to start using the wine. It may not get better and is most likely going to get worse.


EDIT: fixed typo.

 

[Johnd]

Did you use 1/4 tsp of sulfite in each 6 gallon carboy at each of those racking?

 

[JohnBurns]

Yeah, that's a lot of rackings. Given that the wine has been cold stabilized and fined, the color is not good. How many rackings were performed with the pump inserting air? Just the one? I agree with @Johnd that a single racking should not could introduce that much oxidation, but something did. How long did you leave the wine in the primary after fermentation completed?

I can't offer other advice other than to start using the wine. It may not get better and is most likely going to get worse.


EDIT: fixed typo.

More rackings were done because I hoped erroneously that it would help. There was only the one racking that inserted air. The wine was in the primary 11 days until a sp gr of 1.020.

 

[JohnBurns]

Did you use 1/4 tsp of sulfite in each 6 gallon carboy at each of those racking?

Yes 1/4 tsp each racking

 

[Johnd]

Yes 1/4 tsp each racking

Hard to believe you got oxidation with pretty good utilization of sulfite, but it certainly looks oxidized.

 

[winemaker81]

One thing we haven't considered is if the juice was oxidizing before fermentation. I re-read the thread and couldn't spot any obvious problems, when that occurred to me. According to one article, grape juice can oxidize quickly.

@JohnBurns, what was the source of your juice?

For future reference, rack as few times as possible. While this doesn't appear to be the source of your problem, every time you rack you have the potential to introduce contaminants. Ideally I rack 3 times -- after fermentation, after the gross lees settles, and before bottling. In reality, I may have another racking or 2, but I minimize it as much as feasible.

It looks like you have 15 gallons of wine to use up in the near future. I'd refrigerate what you can, to slow down the oxidation reaction. Use the unrefrigerated wine first.

If you don't cook with wine, it's time to start. By this I mean putting wine in the food, although putting wine in the cook is good, too! Wine makes an excellent base for marinades, and white wine works fine for marinating red meat.

Wine drinks to cover the oxidation flavor. I make a quicky Sangria by adding citrus fruit and a bit of sugar. A web search will produce dozens of ideas.

Don't let this discourage you. Serious wine makers have bobbles along the way -- I've had my share.

 

[JohnBurns]

This has been very helpful and I really appreciate the feedback and this forum. The grape juice came frozen from Brehm. I thawed three days and started. I have a Gewurtztraminer and a Sauvignon Blanc batch running parallel and doing great. Since I noticed the pump adding air during racking the Riesling, I corrected before racking the other two. I have only racked them 4 times and will bottle next week.

I like the ideas to salvage the wine. Thanks winemaker81!

 

[cenk57]

I agree with Winemaker81, I believe your juice was oxidized before you even started. Your process looked good, other than the extra racking you did. It appears you sulfited sufficiently during your process to protect the wine. That wine looks clearly oxidized, and sadly, I don't know of any way to fix that.

 

[JohnBurns]

Thanks for the feedback. My first experience with oxidation ...but it won't slow me down!

 

[stickman]

Unless carefully protected, most white wine oxidizes and appears brown during the crushing, pressing, and settling operation. The brown material typically precipitates and falls out during settling as well as during the alcoholic fermentation. It's counterintuitive, but with brown juice it is often recommended to not add sulfite before the AF to prevent the brown color from becoming permanent. Some additional information that may be helpful Winemaking treatment – Hyperoxidation - The Australian Wine Research Institute

I also agree with the others above that the number of rackings seems high for a white wine. It may be helpful to combine steps when possible, like fining and cold stabilizing followed by racking.

There are a few fining agents like PVPP that claim to be able to help with removing the brown color, but I haven't used any of them so I can't comment on their effectiveness. Personally I would make sure the wine falls clear and if still brown, test some of these products before giving up on the wine.

 

[JohnBurns]

thanks all. Appreciate the feedback. The high number of rackings was only because I thought it might help clear the brown color. That is not my normal process. After AF the wine was not brown so I attribute the problem to the pump issue during subsequent racking. I was hopeful I could recover but my feedback unfortunately is you cannot get rid of the brown.

 

[winemaker81]

As @Johnd said upstream, don't fine too much or you can damage the wine. However, yours is an extreme case, so fining again with an agent that strips browning may be a good thing. Anything you can do to extend the wine's lifespan and give you a chance to use it up is good.