Adding Kmeta at first racking?

[BigDaveK]

You realize there is a "Yeast, Additives & Wine Making Science" Forum here.

I'm not sure I understand what more you want? It's a genuine question - what is it lacking? How can we use it better? Can it be improved?

I'm sure "science-y" discussions are spread over all the forums. I don't read everything and I'm sure I missed some interesting information and/or useful links.

 

[Rice_Guy]

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.

Excellent article, ,,, I can see where you are coming from about sulfites making clear pigments.

On a practical level I have seen the pH shift, ex. I can make the bishon dog white after getting mulberry juice on him simply by rubbing on some vinegar. Haven't figured out the salad dressing smell yet.

 

[Shurt1073]

Yes ... I also feel like I'm back at school sometimes but this forum is a great place to learn. Keep up the resources! Us newer wine makers need this guidance from you guys.

 

[winemaker81]

Yes ... I also feel like I'm back at school sometimes but this forum is a great place to learn. Keep up the resources! Us newer wine makers need this guidance from you guys.

Get used to it! School never ends!

As I've said before, I learn something new on this forum every week. Mostly, but not always, related to winemaking. Since most research is either in academia or focused on commercial winemaking, we are our own best resource for home winemaking research.

 

[BigDaveK]

Yes ... I also feel like I'm back at school sometimes but this forum is a great place to learn. Keep up the resources! Us newer wine makers need this guidance from you guys.

I'm a "newer" wine maker, too, at maybe 15 months but I let myself get sucked into numerous rabbit holes. After XX number of wines and hands on experience I'm really understanding the articles and papers a lot better. And like I keep saying, in a couple years I might know something.

 

[Hazelemere]

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.

no sulphite if you want malolactic fermentation to prevent rotten egg odour

 

[distancerunner]

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.

Rather prolific writer with something like five hundred novels, non-fiction, and text books. I can’t speak to his ego but he didn’t drink.

 

[balatonwine]

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.

It will only help in removing O2 in the air space above the wine. But that is not the only issue of where O2 can damage the wine. Any O2 suspended in the wine itself (which can come from many sources) is also an issue, and that will not be affected by the CO2 emitted within the wine. That is were you need Kmeta.

But will adding Kmeta at the first racking hinder the yeast from finishing fermentation?

If you do a natural ferment, without adding commercial yeast... maybe... or not... it may be complicated (when is it not?).

But if you used commercial yeast, that yeast is sulfite tolerant and will not have a problem if you add an appropriate amount.

But, if you want to do malolactic fermentation... then as already said, consider not adding KMeta.

Finally.... when you rack, simply and best to just test your wine for its sulfite level. There are many easy tests to do. And then you will know exactly how much to add -- an appropriate amount, if any. That is the best option. Do the measurements, the calculations and the science. Once you got that figured out, then you can do the art of wine making.

 

[stickman]

Unless there is a particular problem you're trying to resolve, I wouldn't add SO2 to wine that is still fermenting. The main reason is that yeast produce acetaldehyde right before converting the acetaldehyde to ethanol, if free SO2 is present or added, it will bind with the acetaldehyde before it can be converted to ethanol. The wine ends up with higher than typical levels of acetaldehyde bound SO2, which eventually necessitates increased SO2 addition later to keep the acetaldehyde bound and odorless.

 

[balatonwine]

Unless there is a particular problem you're trying to resolve, I wouldn't add SO2 to wine that is still fermenting. The main reason is that yeast produce acetaldehyde right before converting the acetaldehyde to ethanol, if free SO2 is present or added, it will bind with the acetaldehyde before it can be converted to ethanol. The wine ends up with higher than typical levels of acetaldehyde bound SO2, which eventually necessitates increased SO2 addition later to keep the acetaldehyde bound and odorless.

I would say... Yes. And No.

That is (as always), it depends. That is it depends on, for example, how much more fermentation will happen. Near the end... I think the risks are minimal compared to O2 damage. So, by and far, the real issue is of degree. And that is the art of wine making. When to make that call between the two. That is, yes, yeast produces acetaldehyde, but so does O2.

From: The Use of SO2 to Bind Acetaldehyde in Wine: Sensory Implications

The most important non-microbial production of acetaldehyde in wine is due to the oxidation of ethanol (Wildenradt & Singleton, 1974).

Also to consider, that yeast cells are little self contained chemical factories, They make acetaldehyde as an intermediate on a chemical pathway, but do so mostly within their cell walls. They release many chemicals on that pathway mainly as they die off, and before they complete that the full chemical path. And as more die off near the end of fermentation, the more the intermediate chemical acetaldehyde can end up in the wine. So, again, it is complicated. When to rack off those little dead chemical factories and avoid a chemical soup in you wine.

 

[BigDaveK]

Rather prolific writer with something like five hundred novels, non-fiction, and text books. I can’t speak to his ego but he didn’t drink.

Absolutely. I've enjoyed many of his books and consider myself fortunate for spending a couple hours with him. Um, he had a glass of red wine with dinner but maybe he was being polite. And I think Harlan Ellison had the same opinion about his ego. But really, when you're that good how can you not have an ego.

 

[BigDaveK]

Unless there is a particular problem you're trying to resolve, I wouldn't add SO2 to wine that is still fermenting. The main reason is that yeast produce acetaldehyde right before converting the acetaldehyde to ethanol, if free SO2 is present or added, it will bind with the acetaldehyde before it can be converted to ethanol. The wine ends up with higher than typical levels of acetaldehyde bound SO2, which eventually necessitates increased SO2 addition later to keep the acetaldehyde bound and odorless.

Source please.
Seems to me most of the SO2 would be bound in the must. And I know yeast produce SO2 and H2S. Yeast even has an enzyme (NADPH) to break down sulfite in it's sulfate assimilation pathway. I haven't seen any reference to SO2 bonding with acetaldehyde inside the cell walls of the yeast that's why I'm asking for your source.

Also to consider, that yeast cells are little self contained chemical factories,

I've been reading a lot of papers about yeast and I am awestruck at just how complicated they are. Absolutely incredible. And the lab coat folks still don't know everything.

 

[stickman]

@BigDaveK The acetaldehyde issue is discussed in many wine research papers. I generally go with Clark Smith or the AWRI.

"Apart from chemical and microbiological formation, winemaking practices can influence the level of acetaldehyde present in wine; addition of SO2 during fermentation can increase the concentration of acetaldehyde, as can increases in pH and fermentation temperature." https://www.awri.com.au/industry_su...nition-of-wine-faults-and-taints/wine_faults/
"Addition of SO2 in the presence of active yeast will lead to the formation of SO2binders. For every 10 mg/l of SO2 added to the must, bound SO2 levels in the final wine will increase by 3-7 mg/l." Sulphur Dioxide Content of Wines: the Role of Winemaking and Carbonyl Compounds, Cornell University Research Focus 2011-3

"Winemakers divide themselves into two valid camps depending on their terroirs and goals: the Green Juice Club (30 ppm at the crusher for healthy fruit) and the Brown Juice Club (nothing at the crusher).
Bisulfite also binds to aldehydes, principally acetaldehyde, which is the penultimate enzymatic step in fermentation just prior to its ethanol endpoint. As a result, all sulfur dioxide added at the crusher and created by yeasts during fermentation is bound; none is free at the end of fermentation. In fact, the more you add, the more you create an aldehyde pool, necessitating increased addition later. To obtain 25 ppm free SO2 post-fermentation, Green Juice Club members typically add 70 ppm, whereas Brown Juice Club members need only add 50 ppm."
Sulfur Dioxide Basics Revisited, Wines & Vines March 2012 by Clark Smith

@balatonwine I agree, ask 10 winemakers get 20 answers, I'm sure it is an issue of degree, adding SO2 at the end isn't as much of an issue compared to addition at the beginning of fermentation or mid-fermentation. However, the only time I've seen a recommendation to add SO2 near the end of fermentation was in reference to potential bacterial spoilage, that is if Lactobacillus cell counts start rising. Knowing and Making Wine by Emile Peynaud 1984

 

[BigDaveK]

@BigDaveK The acetaldehyde issue is discussed in many wine research papers. I generally go with Clark Smith or the AWRI.

"Apart from chemical and microbiological formation, winemaking practices can influence the level of acetaldehyde present in wine; addition of SO2 during fermentation can increase the concentration of acetaldehyde, as can increases in pH and fermentation temperature." https://www.awri.com.au/industry_su...nition-of-wine-faults-and-taints/wine_faults/
"Addition of SO2 in the presence of active yeast will lead to the formation of SO2binders. For every 10 mg/l of SO2 added to the must, bound SO2 levels in the final wine will increase by 3-7 mg/l." Sulphur Dioxide Content of Wines: the Role of Winemaking and Carbonyl Compounds, Cornell University Research Focus 2011-3

"Winemakers divide themselves into two valid camps depending on their terroirs and goals: the Green Juice Club (30 ppm at the crusher for healthy fruit) and the Brown Juice Club (nothing at the crusher).
Bisulfite also binds to aldehydes, principally acetaldehyde, which is the penultimate enzymatic step in fermentation just prior to its ethanol endpoint. As a result, all sulfur dioxide added at the crusher and created by yeasts during fermentation is bound; none is free at the end of fermentation. In fact, the more you add, the more you create an aldehyde pool, necessitating increased addition later. To obtain 25 ppm free SO2 post-fermentation, Green Juice Club members typically add 70 ppm, whereas Brown Juice Club members need only add 50 ppm."
Sulfur Dioxide Basics Revisited, Wines & Vines March 2012 by Clark Smith

@balatonwine I agree, ask 10 winemakers get 20 answers, I'm sure it is an issue of degree, adding SO2 at the end isn't as much of an issue compared to addition at the beginning of fermentation or mid-fermentation. However, the only time I've seen a recommendation to add SO2 near the end of fermentation was in reference to potential bacterial spoilage, that is if Lactobacillus cell counts start rising. Knowing and Making Wine by Emile Peynaud 1984

I'm familiar with acetaldehyde. My issue was that I haven't read that the addition of SO2 will bind with acetaldehyde inside the yeast cell.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6883346/
https://www.infowine.com/intranet/libretti/libretto7646-01-1.pdf
https://www.semanticscholar.org/pap...erty/1a9fda32e5980abd587ebddb7b2055ab4bdaaae8
https://www.researchgate.net/public...r_dioxide_Strategies_developed_by_wine_yeasts
https://meridian.allenpress.com/jfp...stance-of-Yeast-Species-to-Benzoic-and-Sorbic
https://scholar.google.com/scholar_...year=1997&author=Avram,D&author=Bakalinsky,AT

 

[stickman]

Yea, this winemaking thing is like stepping into a black hole of information. I don't know the mechanism, but yeast have acetaldehyde at their disposal, so I guess they can choose what to do with it.

 

[BigDaveK]

Yea, this winemaking thing is like stepping into a black hole of information.

I fondly remember the days of just throwing things in a bucket...sigh....
It's crazy - I read an interesting paper on yeast or fermentation, don't remember....and then I read another...and then I looked at their citations and found more...and...it never ends. The complexity of the little buggers just fascinates me.

 

[Raptor99]

It's amazing how well things turn out with a simple approach. Yeast are complicated, but fortunately we don't need to understand how everything works. We just need to know how to be good "yeast farmers." But I do appreciate a deep dive into the science once in a while.

 

[balatonwine]

ask 10 winemakers get 20 answers

Funny thing is I first heard it differently. And only when I first moved to Hungary:

If there are two Hungarians in a room, you will still get three opinions...

But I guess since so many Hungarians make wine, it is basically the same thing....

Which is why references, to actual research papers relevant to the topic one claims (with empirical data and objective facts), are best to back up statements, not just web sites no matter how emanate they may be (to avoid an appeal to authority).

 

[balatonwine]

The complexity of the little buggers just fascinates me.

I actually have degrees in Biology** and Ecology. And those litter buggers also fascinate me. And I still do not understand those little buggers. Which is also fascinating.

**When at UCLA, one of my genetics professors specialized in yeast genetics. Even he, then, was trying to figure them out. But one thing I remember the most was his humility about them. Simply saying they gave us the two basics for life: Bread and Beer.****

****Okay, so he was not a wine lover.... But since then, traveling the world (20+ countries, 5 continents) I did learn to appreciate this view, as wine is not universally available, but beer and bread seems to be.

 

[BigDaveK]

Funny thing is I first heard it differently. And only when I first moved to Hungary:

If there are two Hungarians in a room, you will still get three opinions...

Ah, brings back childhood memories. I would add -

If there are two Hungarians in a room and one of them is a woman, there's probably more than three opinions and the guy would be wise to keep his mouth shut.

And -

If there are more than two Hungarians in a room and they're drinking there's probably no opinions, just singing, and a csardas is close behind.