# Stirring during Primary Fermentation



## Jwatson

I am making a WE Selection Estate Barolo. The kit instructions say nothing about stirring during primary, just snap the lid and leave it alone. I am presently aging a WE malbec which I did not stir during primary. It fermented down to .992. Other kits like Mosti Modiale say to stir every day during primary in order to add more O2 and suspend the yeast. I see the benefits of stirring. Should I just follow the kit instructions or stir? I'm a follow the instructions type but am open to good technique. Opinions?


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## Tom

Yes and no.
Yes no stirring needed in WE
No do not snap the lid
Instead lay the lid on top minus the airlock.
Yeast needs O2 in the begining


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## ibglowin

Agree with Tom that no airlock for the first 5 days or so. Just lay the lid on top and cover the hole with something to keep the critters out. 

I have always stirred (per directions) on Cellar Craft and Mosti. Have not made any WE kits. I like the idea of re-suspending the yeast and a gentle stir does just that. If your making a kit with a grape pack then you need to push down the grape pack (to aid in extraction) daily as well.


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## bdcl1977

Does it harm the process in any way if we did stir a kit wine while in the primary stage?


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## cpfan

bdcl1977 said:


> Does it harm the process in any way if we did stir a kit wine while in the primary stage?


More opportunities to not sterilize the equipment and introduce bacteria to the wine. You will probably disturb the CO2 layer that is protecting the surface of the wine if you are stirring at the end of fermentation.

OTOH, if something is floating in the wine, then it should be stirred under. For example, grape skins, elderflowers, oak tea bags.

Steve


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## ibglowin

Pretty sure the wine has more than enough protection in Primary by not only the CO2 escaping into the atmosphere but also that which is dissolved into the wine. 

Just look at the amount of CO2 that is still trapped in the wine when you go to degas. 

Some are worse than others it seems but there is so much CO2 that you should not worry amount oxidation under normal circumstances including gentle stirring to re-suspend the yeast in Primary.


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## robie

Lots if opinions, so I'll toss mine out.

I have had problems with H2S a few times in the past. Each time (and one time was with a W.E. premium kit), it was when I snapped the lid down all during primary fermentation.

There is lots of scientific info out there that says yeast need oxygen the first several days of fermentation. One would be hard pressed to argue with that. 

This says to me that if the lid is snapped down (per W.E. instructions, I know), you are more likely to get H2S, because you are not getting any significant amount of oxygen. I would guess that W.E figures the chances of H2S are less likely than an inexperienced wine maker ruining the wine with bad sanitation practices. 

So, I try to use great sanitation practices, and during primary fermentation (while SG is above 1.000), I lay the lid on top and stir daily. Since I started this practice, I have had no more instances of H2S and I make lots of kit wine.

If you don't want to stir, at least leave the lid settin on top and not snapped down.


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## cpfan

Robie:

My understanding is that one way to ensure sufficient oxygen is in the must is to stir vigourously before pitching the yeast. I also use a large primary with a loose fitting lid, so there is probably some air sneaking into the bucket too.

Haven't had any H2S problems; however, Winexpert uses a broader range of yeast than the other kit manufacturers. Do you recall what yeast was used when you had the H2S problem?

Steve


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## MontyPython

Making my first batch and trying to gain some insight into the whole stirring thing as well. I'm using a _Vinifera Noble - Carmenere_ kit (Using the Lavin K1-1116 yeast), and there was nothing about stirring, or anything that said "leave the lid on loosely".

I was getting a pretty strong smell also on day 3. That old yeast, dirty sock, slight rotten smell. Moved it into a vented area of the basement so that it didn't stink up the whole house. I also cleaned out the wine that crepped into the airlock.

Back on topic, however... I'm now 5 days into fermenting. It's still bubbling like crazy, and I haven't yet unsnapped the lid, or stirred it. Is it too late for this? Should I pop the lid off and give it a few good stirs, and then leave the lid on loose for the remaining few days of primary? 

It makes sense to let some O2 in, but then I keep reading things about, "use the barrier of CO2 at the top of the plastic primary fermenter to keep the O2 from spoiling the wine". 

All good info, but some of it contradicts others. I appreciate your advice!

Stephen


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## robie

Stephen,

I read once that you can ask 10 different wine makers a question and get back eleven different answers. This is not rocket science, so each of us over a period of time tend to do things by "what has always worked for us".

So, if you go by your kit instructions, using the kit supplied yeast, and it doesn't say anything about snapping or not snapping the lid down during primary, you likely won't have to worry about it, one way or the other

Have you been taking specific gravity readings with a hydrometer?

Here is my own personal experience:
During primary, the yeast need oxygen; during secondary (and thereafter), they need to be kept from oxygen. That is a scientific fact, regardless of the kit instructions. Now that's why I stir during primary. 

While in primary, it is not a good idea to seal the wine from any and all oxygen. I believe the foam should be stirred in on a daily basis, better if done twice a day. Also, stirring is especially necessary if you have added a grape pack. If left on top too long, the grape pack can produce mold and/or start rotting. 

However, if no grape pack and if you are not getting a lot of foam and your lid is not snapped down (sealed), you should be getting enough circulation to be OK. I say "OK", but I will always stir it anyway. 

Being OK is more true if you are using a very robust yeast like EC-1116 or EC-1118 and a few other of the "Mack Truck" yeasts; they are very good at getting the job done correctly, even under not so great conditions, like having the lid sealed during primary. I typically don't use these particular yeasts, which is part of the reason why I got H2S in the past.

Now if you don't practice very good sanitation, you would be better off not opening the wine to stir, but I'll assume you are going to always sanitize your stirring spoon and do it correctly.

My advice - Don't seal the lid during primary, don't leave lid so critters can get into the wine; stir the foam down at least once a day using a well sanitized stirrer... That's one of eleven!


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## MontyPython

Robie,

Thank you for taking the time to chime in. VERY helpful!

That's what I'm kind of gathering as I continue to do research. Heh, 11 different answers seems only to be the beginning - and that's probably why there's 1000's of producers out there, all of which manage to make wine, but not all of them are able to make GOOD wine. 

I'm actually very excited about the learning process, and want to gather enough to not make unnecessary noob mistakes, but not so much that I don't have the opportunity to figure out what works for me. Otherwise I'll just be making the same wine that anyone else with the kit is!

Following your (and a few others) lead, I popped the cover this evening (day 5). A few observations I'll share:

First, note that I'm not using grape pack, but from the description it sounds like you can probably purchase crushed grapes to float on the top of your juice, to help introduce some more characteristics that you would find in a winery's process. True?

When I removed the lid, there is actually NO foam at all. So, maybe I've been getting enough O2, so maybe I've been OK.

I took a SG reading and from a starting level 5 days ago at 1.85... I'm now down to 1.35. That I would say is encouraging. 

I gently stirred the wine with my sanitized spoon. Btw... I always spray it down with some Potassium Metabisulfite sanitizer. I let it sit for a few minutes and then use it wet. Good? Bad? OK?

I put the lid back on and just snapped down on two sides just to make sure it doesn't shift... but it isn't sealed all around. Filled the airlock with some more K2S2O5, and put it into the lid.

Not much bubbling again yet, but I gather it has to build up CO2 levels again inside the top area. There is about a 3" gap from the top of the liquid to edge of bucket.

I'll continue to give it a light stirring over the next few days and monitor the SG until it gets down to about 1.10 ish - which from what I've read is a good point to rack.

@Jwatson - sorry to hijack your old thread –*hopefully this has been helpful to you as well.

Best,
Stephen


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## wineh

This is an interesting thread, with 11/10 opinions. My primary fermenter does not have an airlock, nor a tight seal. I have never stirred a kit during fermentation, and I was a little confused about that one. Even the 6 week Cellarcraft kits (which I have made more than a few of) don't mention stirring, but the grapeskin kits do. 
There is about a foot of headroom in my primary, so I'm thinkin' there would be enough oxygen to start fermentation, and then it would be displaced by CO2, protecting what is then wine from oxygen. My theory may not hold water, but it has worked for all these years.


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## Charlietuna

My opinion shouldn't count for too much due to me being a complete novice, but here's what I'm doing. I have made 2 kits. Both with tea bag & fruit bags. So I've felt like I should be stirring to keep these wet & to get the maximum flavor & color out of them. I just set the lid on the bucket. No air lock & a dishtowel over top. I open it twice a day & stir with a well sanitized spoon. One down side to stirring 2x a day is that both times I've busted the tea bags full of wood chips. I think next time, I'll dump the grape skins in the hops bag, tie a knot, then cut open the tea bags dump them n the hops bag & tie another knot. Or just dump it all in together. But keep it in the hops bag. 

Again, I'm just starting out, but this is what I'm doing & it's working so far. I've had no issues with opening the primary 2 times a day. 

Brian


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## ibglowin

If nothing else, stirring during primary adds a bit more O2 as well as re-suspending the yeast that has settled to the bottom of the bucket helping to ensure as complete a fermentation as possible.


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## MontyPython

Thanks everyone for your insight. I'll let you know how things pan out...


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## bstnh1

I use a 7 gal. Fermonster for fermenting; mix the juice & water vigorously with a drill before pitching yeast; cover the open top with a couple of layers of cheesecloth and don't stir during primary fermentation. I've made a lot of WE kits and have never had a problem with H2S or getting it to ferment to dry. Just pouring the juice and water into the fermenter and mixing it vigorously with a drill attachment seems to add plenty of oxygen to keep it perking.


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## sugar

Now,that rings a bell. Mix with a drill and wand before pitching the mack truck yeast. That will definitely get more than enough O2 to do the Biz. Having got O2 poisoning when degassing once.
Lose lid. Leave it alone until finished its part.
I'm going to do this next time.
Thanks


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## balatonwine

Yes, lots of opinions being expressed. That is the "art" of wine making.

Regarding O2 exposure, I tend to agree with this more objective assessment:

_An analysis of faulty wines at the well-known International Wine Challenge in London showed that oxidation or reduction are the two most important sources of faults, which occurred the most in wines. It is the extremes of oxygen exposure, either too much or too little. The controlled exposure to oxygen can, however, prevent both problems._

And for a bit more information, a bit thick, but human readable, I recommend "Guide to Macro Oxygenation and Fermentation".

And for the real science geeks, "Effects of oxygen supply on yeast growth and metabolism in continuous fermentation".


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## sugar

Some good imfo for the hobbist.
Can be applied to the process some what.


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## Ajmassa

balatonwine said:


> Yes, lots of opinions being expressed. That is the "art" of wine making.
> 
> Regarding O2 exposure, I tend to agree with this more objective assessment:
> 
> _An analysis of faulty wines at the well-known International Wine Challenge in London showed that oxidation or reduction are the two most important sources of faults, which occurred the most in wines. It is the extremes of oxygen exposure, either too much or too little. The controlled exposure to oxygen can, however, prevent both problems._
> 
> And for a bit more information, a bit thick, but human readable, I recommend "Guide to Macro Oxygenation and Fermentation".
> 
> And for the real science geeks, "Effects of oxygen supply on yeast growth and metabolism in continuous fermentation".



So you like a controlled o2 exposure during fermentation. But how ‘controlled’ does controlled mean? Punching the cap/stirring for specific lengths and frequency? sMacro oxygenation link isn’t working btw. 

I’ve got a theory about this myself. With absolutely no science to back it up. Just gut. 
A fermentation under airlock with minimal o2 exposure may very well create a wine no different then an open ferment. But the one under airlock is like the boy in the bubble. The open ferment gets accustomed to o2– builds up a tolerance. Not just during the ferment but later too. When racking, testing, sampling etc.. just not fearing o2 at all. And the exposure it does get ends up benefitting the wine. Especially when micro oxidizing in a barrel after. And gives the aging process so much more to work with. 
The boy in the bubble never got any air and is scared of it. So later on if it did randomly get exposure it would have a more quick and drastic effect that wouldn’t be beneficial. No tolerance. For him to grow to be an old man needs to stay in his bubble forever. 
Caring for your wine so much that you keep all o2 away from fear of negative effects is like the little girl who loved her puppy sooo much and hugged him sooo tight that she accidentally hugged him to death.


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## Scooter68

Not sure about the over protection idea but, I tend to believe that during an active ferment there is sufficient gassing off occurring to protect the wine providing there is no breeze or other interference with the natural layer of gas on the surface of a fermentation bucket. However, when the fermentation slows, the blanket will dissipate and that would the time when a transfer to an airlocked carboy would be advised.

Tonight I should have taken a couple of photos to provide an idea of what I mean. Tonight less about 30 hours after I pitched the yeast in a batch of Mango/Pineapple Wine I stirred the must for the third time. This morning at 8:30 ( about 15 hours after pitching the yeast), there was about a 1/4 to 1/2 inch cap of foamed up pulp from the fruit. I stirred to get it moist again. About 5:00 this afternoon I did the same thing and the cap was about 1/2 to 3/4 inches thick. Then a few minutes ago at 10:15 I stirred it again and the cap was at least a inch thick. As soon as I stirred it the must frothed up like a root beer float with large and small bubbles from a very active fermentation. In conditions like this the gasses coming off are clearly going to form a blanket under that cloth cover. The pulp itself further supports that blanket and protects the developing must from too much oxygen. Now when this batch drops below about 1.020-1.010 and the bubbling after I stir is not there anymore, THEN I'll get it racked off the pulp and into a carboy. Oh, yeah as things progress and I know racking time is coming up. I'll not stir things off the bottom anymore so the pulp can drop out as I need it to.

I think the debate on this won't be solved by any of us but at least we can make informed decisions based on what works for us AND pass that reasoning and our results on to those just getting started in this hobby. After all isn't that what this forum is all about - to share and educate and bounce ideas around?


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## balatonwine

Ajmassa5983 said:


> So you like a controlled o2 exposure during fermentation. But how ‘controlled’ does controlled mean? Punching the cap/stirring for specific lengths and frequency?



Controlled as anything that is predictable, consistent, intended, and/or measurable.

If you can measure it or predict it from known data (eg -- the O2 permeability of a flextank), you can learn the ideal exposure you want faster. Else you are left to far greater trial and error, which takes longer to perfect (maybe years, or decades .....)



Ajmassa5983 said:


> sMacro oxygenation link isn’t working btw.



Thanks. I corrected the link in the original post. And here is the direct link as well:

https://morewinemaking.com/articles/Macro_oxygenation_fermentation


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## Ajmassa

Scooter68 said:


> Not sure about the over protection idea but, I tend to believe that during an active ferment there is sufficient gassing off occurring to protect the wine providing there is no breeze or other interference with the natural layer of gas on the surface of a fermentation bucket.



I’m positive I did not just come up with this theory on my own. Partly it’s from growing up with winemaking and partly my own winemaking experiences. But there was definitely an article that connected the dots for me. Gonna try and dig that up. 
And btw the ‘over protective’ vs ‘building o2 tolerance’ is referring to red wine only.


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## Ajmassa

This is not the article I was referring to— but a good one nonetheless. It was definitely in a winemaker mag issue tho. 

*silver lining— searching online and renewed my subscription that I found out has been expired for a while.


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## Scooter68

Ajmassa5983 said:


> I’m positive I did not just come up with this theory on my own. Partly it’s from growing up with winemaking and partly my own winemaking experiences. But there was definitely an article that connected the dots for me. Gonna try and dig that up.
> And btw the ‘over protective’ vs ‘building o2 tolerance’ is referring to red wine only.



Not taking 'issue' with your thoughts BTW. I'm more of the belief that the most important thing is solid safe practices that are repeated consistently. As long as it works for you that's the key. As you mentioned red wines (Grape wines) are a different creature from what I do all the time - Fruit wines - Blueberry, Peach, Blackberry, Black Currant, Mango. The needs and tolerances of these fruits is a bit different from a Grape wine where adding sugar is rarely done with a wine grape. And within these fruits there a wide variety of characteristics. Peach and Mango are fairly close in characteristics and nothing like a blueberry or blackberry wine.

What you advocate is not radical at all to me.

By the way I'm about to post a progress report on my Mango-Pineapple wine under the Country Fruit Wine making section. In it I'm posting photos of the thick cap of pulp and the bag is creating - to me that's an example of the built in Oxygen protection that an active ferment provides. Not all fermentations I do have a cap like this. Some have nothing but a few floating 'islands' of bubbles unless you give it a good stir and then in 5 minutes the foam dissipates.


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## Ajmassa

Scooter68 said:


> Not taking 'issue' with your thoughts BTW.



Didn’t think you were. If I seemed confrontational it wasn’t intentional. I was just posting some info I found while looking for a specific article. All good Scoot. 



Scooter68 said:


> The needs and tolerances of these fruits is a bit different from a Grape wine where adding sugar is rarely done with a wine grape. .



Not gonna be rare this season! Fully plan on proceeding with the winemaking faux pas of bumping the sugar level! And the acid. And whatever else I need to. No health inspectors visit my house. And it’s my wine I will do whatever I want! And can’t wait!

I’ll give that mango thread a look-see. Sounds interesting.


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## Scooter68

In my early reading to learn about wine making I was wading through some heavy reading. They were clearly talking about grape wines and European standards. I didn't realize that at first and wondered... Adding sugar was spoken of as a crime, verboten in some circles and perhaps in some jurisdictions. Thankfully we don't have "Wine Police" here. And there would be almost no country fruit wines or they would be pretty wimpy if adding sugar was a no-no.


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## Ajmassa

Scooter68 said:


> In my early reading to learn about wine making I was wading through some heavy reading. They were clearly talking about grape wines and European standards. I didn't realize that at first and wondered... Adding sugar was spoken of as a crime, verboten in some circles and perhaps in some jurisdictions. Thankfully we don't have "Wine Police" here. And there would be almost no country fruit wines or they would be pretty wimpy if adding sugar was a no-no.



I think it’s a big no-no simply because of our location. Living in US- wine/winemaking is synonymous with California. And in Cali they have set standards for additions. The hoity toity vineyard areas don’t seem to struggle for ripeness. A good grower should be able to get high Brix with that locale. So there’s a limit to sugar additions for them since it shouldn’t be needed anyway. But the acid flip side of it - the struggle is real. And additions are common place and we don’t think anything if it. 
And I’m pretty sure it’s kind of opposite in France. Where they can get good acid levels but struggle for Brix— and they have more relaxed sugar limits. And I’d bet the adverse for acid. 
I listen to podcasts with winemakers at times. I’ve heard Napa guys scoff at the French for adding sugar and also heard Frenchies turn their noses up to tartaric additions.


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## Scooter68

That sound about right. And for grins... I saw a vineyard on the Rhine that mentions getting some root stock from the USA because of some blight or disease.


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## Johnd

I don't go nuts trying to keep my red wines from getting some oxygen exposure, in fact, like to make sure that they get some. My punchdowns are typically vigorous and no doubt introduce oxygen, a loose fitting cover over the vessels is my norm, racking out of the fermentation vessel and into carboys introduces oxygen as well. When pressing, buckets catching free and press run juice from the press are open topped through the whole process. Next couple of rackings are by gravity with splashing into the target carboys, as is the process of racking into barrels. Typically, the only vacuum racking I'll do will be to remove the wine from the barrel if it's not a 6 gallon, only because the bigger ones are harder to lift to rack by gravity. My last rack before bottling is also a splash racking. I believe that some O2 in the process is beneficial to red wines, to a point..........


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