Adding Kmeta at first racking?

[Raptor99]

I was wondering if you add Kmeta when racking from primary. Normally I would add Kmeta every time I rack the wine, but many have advocated racking out of primary once the SG drops below 1.010. In that case, the fermentation is not quite finished. It will continue to emit CO2, which will help protect the wine in the secondary. That makes a lot of sense. But will adding Kmeta at the first racking hinder the yeast from finishing fermentation?

Please share your experience on this.

 

[Rice_Guy]

I am one of the folk who will add k meta after racking into a carboy with airlock at 1.020 +/- ,,, I could see skipping it with red grape because tannins are an anti oxidant. With fruit and whites it seems worth while to always have some level of protection. If I made a change to skip meta at the first racking I would change process to put a double dose of meta in when I rack off gross lees, and then let the carboy sit unopened till I am ready to bottle.

 

[BigDaveK]

I currently add when racking from secondary but that may or may not change.
It shouldn't affect the yeast. In fact I had a stuck fermentation restart after it's addition.
Yes, the CO2 offers one kind of protection but the SO2, in addition to oxygen, will also bind with carbonyl compounds, some sugars, anthocyanins, quinones, ketonic acids, and more.
It's one of the nuts-and-bolts facets of wine making I'm still looking into.

 

[distancerunner]

Like so much in winemaking, and every other craft, it depends.

If you’re planning to inoculate with malolactic bacteria it’s a hard no. If not, it’s up to you because while fermentation still ongoing the yeast are producing CO2. That acts as a barrier against oxygen.

We typically do not rack before alcoholic fermentation is complete. Especially for reds because we usually will do extended maceration to maximize color and tannins.

The caveat is that we use grapes. Juice and kits, it’s up to you.

 

[winemaker81]

I add K-meta at each racking, post-fermentation.

However, David's (@Rice_Guy) point about whites makes sense. Since I started using overnight starters, every ferment has gone like gangbusters, so my concern about K-meta hurting the ferment is much lower. An interesting experiment is to make a batch of white, rack it at 1.020, divide in 2 batches and add K-meta to one.

Has anyone noticed that in about every 3rd post I read, I think of an experiment?

 

[distancerunner]

I add K-meta at each racking, post-fermentation.

However, David's (@Rice_Guy) point about whites makes sense. Since I started using overnight starters, every ferment has gone like gangbusters, so my concern about K-meta hurting the ferment is much lower. An interesting experiment is to make a batch of white, rack it at 1.020, divide in 2 batches and add K-meta to one.

Has anyone noticed that in about every 3rd post I read, I think of an experiment?

Some of us don't have the lab fetish that you do.

 

[BigDaveK]

Okay, I got two more things -

I remember reading in WineMaker Mag that SO2 temporarily binds with polyphenols reducing the amount available to bind with tannin. It also hinders the process where color and tannin bind so frugal use of SO2 should be considered for the first 6 months. I don't have a corroborating source yet.

Also, wine yeast is genetically resistant to SO2. Those incredibly beautiful little creatures adapt to harsh environments by undergoing "chromosomal rearrangement". Jeeze Louise, I find them more and more remarkable every day. If you're interested, the gene controlling SO2 tolerance is designated SSU1. I save papers as PDF's but if anyone is interested I can figure out the link and post.

 

[winemaker81]

Some of us don't have the lab fetish that you do.

Fetish??? Nope -- curiosity, as in that thing that killed the cat.

As I've mentioned in other posts, most grape & wine research is either academic or focused on the commercial industry, which makes sense. While a lot of the results can be applied to the home winemaking market, a lot of it is either complexly technical, it doesn't scale down to our size, or it's too expensive for non-commercial use.

So, like Dave (@BigDaveK), curiosity strikes me and I think of practical experiments that answer questions we may have (or maybe just me), and expands the communities collective knowledge.

 

[distancerunner]

Wasn’t a slam. I applaud you guys for doing experimental wines.

We only do a crush in the fall and spring. Too many hobbies plus life interfere with making monthly wines.

 

[winemaker81]

Wasn’t a slam. I applaud you guys for doing experimental wines.

We only do a crush in the fall and spring. Too many hobbies plus life interfere with making monthly wines.

I realized that, but it could have been taken that way, so I replied to (hopefully) show I didn't see offense.

text is a tough medium for communication!

 

[wineview]

There have been times when I would rack out of primary into a carboy and not add kmeta at all until my third rack or nine months. I was thinking I could squeeze a few more gravity points during that time. All those wines turned out fine. Of course I was topped up within an inch of the bung.

 

[heatherd]

I wait until fermentation is done, then add kmeta roughly every three months.

 

[BigDaveK]

I realized that, but it could have been taken that way, so I replied to (hopefully) show I didn't see offense.

Good job, Bryan! Sometimes the first word we think of isn't the best. "Fetish" wasn't the best.

So, like Dave (@BigDaveK), curiosity strikes me and I think of practical experiments that answer questions we may have (or maybe just me), and expands the communities collective knowledge.

Wow, I think life would be so boring without an abundance of curiosity. Sometimes I just plain need to know the why or the how.

 

[BigDaveK]

Wasn’t a slam. I applaud you guys for doing experimental wines.

We only do a crush in the fall and spring. Too many hobbies plus life interfere with making monthly wines.

Monthly!?!? Because of the sad reality of rapidly decreasing storage I'm trying to do monthly. I'm at bi-weekly now so I'm getting a little closer.

BTW, I noticed your avatar. I had dinner with Asimov in the mid 70's, about 8 of us. He was planning a book on dirty limericks and that's pretty much what occupied the conversation that evening. And I recall he had a huge ego.

 

[Rice_Guy]

tannin is a polyphenol, polyphenols are a large family which includes pigments. Classical definition of tannin is that it will bind with protein/ can be measured via wet chemistry by precipitating with a protein. ,,, Curious how recent in Winemaker Mag? I haven’t read that.

Okay, I got two more things -

I remember reading in WineMaker Mag that SO2 temporarily binds with polyphenols reducing the amount available to bind with tannin. It also hinders the process where color and tannin bind so frugal use of SO2 should be considered for the first 6 months. I don't have a corroborating source yet.

Also, wine yeast is genetically resistant to SO2. Those incredibly beautiful little creatures adapt to harsh environments by undergoing "chromosomal rearrangement". Jeeze Louise, I find them more and more remarkable every day. If you're interested, the gene controlling SO2 tolerance is designated SSU1. I save papers as PDF's but if anyone is interested I can figure out the link and post.

An interesting thread @winemaker81 and Dave, ,, I am part of the science committee in Prairie Vinters so get buckets of juice to experiment with. What questions do you see that need to be answered to make home wine making better? ,,, In the last two years/ since starting tannic apple varieties, ,, I have been looking at polyphenols a lot, ,, and adding apple tannin to everything from Briana to rhubarb juice.

Does Wine Making Talk need a science group?

 

[BigDaveK]

Sorry @Rice_Guy. Perhaps instead of saying "I read that..." I should also include a link if possible.
I don't have a subscription to Wine Maker Mag so I'm limited to the free articles. Here you go -

https://winemakermag.com/article/so2-fundamentals
I've also acquired an interest in polyphenols as it relates to my country wines. Here's one paper, deals with polyphenol content and wine quality:

https://pubmed.ncbi.nlm.nih.gov/33573150/
This has turned into an exciting hobby for me. I feel like I'm back in school and learning again. I have to admit parts of my brain are rusty but I'm getting there.

 

[ChuckD]

Does Wine Making Talk need a science group?

Is this a trick question?

 

[Raptor99]

Sorry @Rice_Guy. Perhaps instead of saying "I read that..." I should also include a link if possible.
I don't have a subscription to Wine Maker Mag so I'm limited to the free articles. Here you go -

https://winemakermag.com/article/so2-fundamentals

Great article, thanks for sharing the link. One part jumped out at me:

SO2 binds with various phenolics, including color molecules (this is why SO2 can temporarily bleach color), which, for reds just after fermentation, means those color molecules that bind with SO2 are not available for binding and stabilizing with tannins. Also, SO2 short circuits the process by which color and tannin ideally polymerize, thus SO2 added at this time can have adverse effects on wine structure and longevity. Most color/tannin binding happens within the first 6 months of aging, so additions after 6 months would be the preferred timing, unless you are finding any spoilage bacteria odors prior to that.

That means that there is a downside to adding Kmeta too soon because it can "have adverse effects on wine structure and longevity." The author recommends delaying addition of Kmeta until after 6 months of aging. That is at odds with the usual practice by most on this forum. Any comments?

+1 for a forum on Wine Making Science.

 

[wineview]

Great article, thanks for sharing the link. One part jumped out at me:

That means that there is a downside to adding Kmeta too soon because it can "have adverse effects on wine structure and longevity." The author recommends delaying addition of Kmeta until after 6 months of aging. That is at odds with the usual practice by most on this forum. Any comments?

+1 for a forum on Wine Making Science.

I'm all ears on this one.

 

[Ohio Bob]

More articles from Wine Maker Magazine...
The Science of Winemaking, Understanding Wine Chemistry by Clark Smith, Dec 22/Jan 23 issue.
Sulfur Dioxide, Fact and Myth by Clark Smith, Feb 23/Mar 23 issue.

“Clark Smith, one of California’s most widely respected winemakers.”
Excerpted from his contributors bio.