What is the CORRECT way to displace ambient air from headspace ?

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chonn

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I wouldn't ask this question if I was using a carboy and had a few inches of headspace ...

I am asking because I often find myself with a 14 gallon stainless container with, say, 2-3 gallons of headspace in it. That is a TON of headspace.

The way I manage this, currently, is I pour high-flow (regulator open all the way) co2 in through the bung-hole until I'm pouring out clouds of vapor like some witches cauldron and then QUICK put the stopper in.

This seems to work. I think. But I have no way of knowing and I would really like a real, repeatable, teachable, process that I can be sure of. I don't want this important step to be dependent on how fast my hand moves or how full the co2 bottle is. I am worried there could be turbulence or eddies inside the container that allows some big pocket of ambient air to remain inside even though I am pouring in so much co2.

So anyway ... how would they do this in a lab ?

Forget winemaking .... we're in a lab and I have a container and there is ambient air in that container that I absolutely MUST displace completely with some other gas.

How do they do it ? What is the tooling ? What does this process look like ?

I'm fairly inventive but I am really at a loss here - the best I can think of is to drill a secondary hole in the lid, then place the bung stopper in place with the co2 line going into it, and a vacuum pump line going into the secondary hole and then pouring in the co2 while simultaneously pumping air out ... and then just pinch both lines.

That's the best I've got and it still seems like a fingers-crossed kind of hack.

How would (lab) pros do this ?

Thanks!
 

Ohio Bob

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In a totally unrelated industry I have seen two possible methods, vacuum fill and bubblers.

Vacuum filling requires pulling a vacuum on your headspace, flipping a valve and introducing CO2. Then close off all your valves and disconnect.

Bubblers “trickle” a small flow rate continuously using a low flow rate regulator. Plastic devices filled with a liquid let you see the bubble rate. Kind of like an airlock.

These options seem problematic in many ways.
 

Rice_Guy

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the best test is that it works, you are not developing oxidation flavors,
This seems to work. I think. But I have no way of knowing and I would really like a real, repeatable, teachable, process that I can be sure of.
I like to be able to measure therefore I would have some gauges on the stopper. That said any metal lines need to be plumbed as if you were running natural gas. Teflon tape and mechanical seals aren’t the best.
* one method which you suggested is pull a vacuum as half an atmosphere or more > vent inert gas into the head space > pull a second vacuum followed by venting inert gas in > repeat cycle a third time and seal it off. This is similar to what I am doing, except that my pump will do 22 inches Hg (roughly .75 atmosphere). Your preferred gas is nitrogen or argon which are less soluble than CO2.
Logic the first cycle can be assumed to cut the oxygen by 50%, a second cycle cuts that in half ie 25%, a third cycle cuts that in half ie 12.5%, adding a fourth cycle gets you to 6.25% of original atmosphere etc. (with my pump the percentages original are higher)
* second method get some wine bags as Bag-In-Box which are oxygen barrier film > fill the bag with a gas or even compressed air so that the head space is isolated from the liquid In which case you don’t care if oxygen is there.
* third method I have seen is to have tubes going to each plastic tank and keep the ullage at about an inch water column pressure with nitrogen. UC Davis has plastic shrouds over floating cover SS tanks which they put a slight positive pressure nitrogen into.
* Nomacork/ Vinventions has a sensor which goes in a glass bottle. One can pulse UV on it to get a read out of what the internal oxygen is without breaking a seal. They may have other oxygen monitoring tricks for sale too.
 

CDrew

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The simplest method is to use a different container, or additional smaller containers that can be kept full. A 14 gallon container sounds like a keg maybe? Some pictures would be helpful.

The second method is to make sufficient wine to fill your vessel completely.

But O2 is miscible in CO2, so CO2 is unlikely to be more than a temporary solution unless you have a clamped down occlusive stopper like a triclamp system.

And because all stoppers breathe to some degree with temperature changes, I don't think you will succeed going down your current path. After your wine is wine, almost any amount of O2 is bad for it (except the tiny controlled amount that aids the aging process).
 

barryjo

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First off, I have found temperature has little to do with an airlock breathing. It is primarily atmospheric pressure changes we are concerned with. I have watched a carboy partially filled with finished wine start to bubble when a low pressure system (storm) comes thru. Another solution is to install a larger airlock. As in DIY. A piece of tubing out of the drilled stopper into a larger container works well. Like an empty bottle, say around 6-8 ounces. Not critical. Fill bottle with a water/k-meta solution. Or as has been suggested, make bigger batches or use smaller primaries.
 

Steve Wargo

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I wouldn't ask this question if I was using a carboy and had a few inches of headspace ...

I am asking because I often find myself with a 14 gallon stainless container with, say, 2-3 gallons of headspace in it. That is a TON of headspace.

The way I manage this, currently, is I pour high-flow (regulator open all the way) co2 in through the bung-hole until I'm pouring out clouds of vapor like some witches cauldron and then QUICK put the stopper in.

This seems to work. I think. But I have no way of knowing and I would really like a real, repeatable, teachable, process that I can be sure of. I don't want this important step to be dependent on how fast my hand moves or how full the co2 bottle is. I am worried there could be turbulence or eddies inside the container that allows some big pocket of ambient air to remain inside even though I am pouring in so much co2.

So anyway ... how would they do this in a lab ?

Forget winemaking .... we're in a lab and I have a container and there is ambient air in that container that I absolutely MUST displace completely with some other gas.

How do they do it ? What is the tooling ? What does this process look like ?

I'm fairly inventive but I am really at a loss here - the best I can think of is to drill a secondary hole in the lid, then place the bung stopper in place with the co2 line going into it, and a vacuum pump line going into the secondary hole and then pouring in the co2 while simultaneously pumping air out ... and then just pinch both lines.

That's the best I've got and it still seems like a fingers-crossed kind of hack.

How would (lab) pros do this ?

Thanks!
How about adding Dry Ice (CO2) to purge the headspace? That way you can measure it.
 

chonn

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OK, many interesting responses - thank you.

First of all, the containers I use are these stainless steel primary fermenters:


They are 14 gallons in size. There are not 11 or 12 or 13 or 13.5 gallon sizes so no matter what I am going to have 1 or 2 or 3 gallons of headspace. Note: they are perfectly airtight - gasketed with 5 clamp locks and I have tested several of them with fine vacuum gauges over months and they lose no vacuum. So they are tight.

This is a single vintage, single vineyard product I am making and my 400 grapevines make what they make - if it comes out to 11 gallons that is what it comes out to.

Yes, certainly I could get a 7 gallon fermenter like this, and a 5 gal carboy, and then ... mix and match containers like that but not only does this diminish any real value in bulk aging prior to bottling it also adds more reps and more variables AND dosing and measuring additives like KMBS or acid are double the work and different calculations, etc.

So the bottom line is, the 11-13 gallons that my vineyard makes is going into one final container - this one.

* one method which you suggested is pull a vacuum as half an atmosphere or more > vent inert gas into the head space > pull a second vacuum followed by venting inert gas in > repeat cycle a third time and seal it off. This is similar to what I am doing, except that my pump will do 22 inches Hg (roughly .75 atmosphere). Your preferred gas is nitrogen or argon which are less soluble than CO2.

Yes, this is where I am going as well ... although you're saying start with 100% ambient air and cut it by halves with each rep - I would be more aggressive and dump co2 into the headspace initially, like I have been, AND THEN cycle the vacuum/co2 for a few reps.

So instead of 50 -> 25 -> 12.5% ambient air, I would be going 5% -> 2.5% -> 1.25% ... (assuming I had only 5% ambient air initially).

... which means a second hole drilled and cleaned up (and gasketed) on the lid. That's pretty easy and I can vacuum test it with water and air for a month and be sure it doesn't leak.

Here are some closing thoughts:

1) I would, still, really like to hear from some lab tech somewhere - or some industry tech - not connected to winemaking. How do people do this in a lab ? I don't think they're using plastic baggies. They MIGHT be using a co2 generator like dry ice but, again, I'd love to hear something that sounds like "the real way people do this".

2) It seems to me that there is a difficult valley between very small production (2-5 or even 9-10 gallons) and, say 500 or 1000 gallons. Everyone knows exactly and perfectly how to deal with one or two carboys. At the same time, I think the pros at big wineries have very nice (and very expensive) methods of dealing with 500 or 1000 gallons. But if you have 15-30 gallons you're stuck (re)inventing things.

Does that ring true to you ?
 

ibglowin

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I could not see in any other post you've made how long you intend to leave wine stored in these vessels?

Are you using these for primary AF only? Long term storage of sorts? If so why would you wish to use something sold as a "fermentor" for long term storage?

How many of these do you have?
 

chonn

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I could not see in any other post you've made how long you intend to leave wine stored in these vessels?

Are you using these for primary AF only? Long term storage of sorts? If so why would you wish to use something sold as a "fermentor" for long term storage?

How many of these do you have?


We crush into two of them and do primary in those two.

Then we press off the skins into one of them and do ML in that one.

Then we rack back and forth and clarify, etc., and finally bulk-age in it.

I have four of them - two are just pots, basically, and two of them are ported at the bottom.

So right now the entire batch of wine (again, 11.5 - 12 gallons) is bulk aging in one. When it is time to bottle, no siphoning - just attach tube to the port/valve at the bottom and put a cane on the other end. That's a big plus.

In fact, I never do any siphoning - once primary is done and we press off the skins it is always in one of the ported ones so I can always rack one to the other without siphoning.

They call them fermenters but with a gasketed, latched, airtight lid (and optional valve port) they are obviously used for many general purpose beer and wine functions ...
 

Rice_Guy

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* old technology “family wine” in Italy would be in a straight side crock with bottom spigot. There is a wooden round that floats on the surface and further sealed with some olive oil on the surface.
* What Dave suggests is very easy with an open top stainless. I would consider using oak as the wooden round as the float, ,,, take a silicone baking mat and cut a circle which is 1 cm larger than the tank, ,,, visit the local plastics shop to have them laser cut a fairly tight acrylic circle on top of that, ,,, and bolting the sandwich together.
* LDPE is lighter than dry wine at 0.990 and a floating skin could be cut out of half inch LDPE sheet.
* early in this thread there was a comment about over thinking this. With your large removable cover I would be tempted to sink some food grade bottles of water (LDPE/ PET/ glass) with a few stainless bolts. It really wouldn’t take much tweaking to get to 5mm ullage. ,,,, if I was paranoid about leakage I would take labels off store bought grain alcohol bottles.
* you asked for lab tools, there are CO2 generators tablets which go in an anaerobic microbiology canister that has a catalyst that scavenges oxygen. Never asked but likely not food grade.
* the standard to determine how well a beverage is carbonated is simply dial in the gas pressure at a known temperature. I want to say that the QA tests are about $50K but I never needed a set up.
Crazy idea...
Food grade plastic cut into a circle, laid on top of the wine. Bucket lid? Cutting board?
 
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CDrew

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You are kind of fighting the obvious. Wine needs to be topped up into a neck like environment for long term bulk aging. Keep the surface area small. It isn't hard. Carboys, barrels, kegs, demijons and flex tanks, all developed for wine making hold to this simple principle. If you are aging in your fermentors for 2-3 months, a stop gap shot of CO2 will likely suffice. But for a year or two of bulk aging you are setting yourself up for failure.

In the commercial world, tanks and nitrogen systems can make up for a lot of surface area problems. At the home level it's different. But the principle is the same. Oxygen in general is bad for wine.

What you show is beer making equipment and it looks great for that. But wine making is different and requires different techniques (though there is lots of overlap). Just the way it is. Beer is bottled fresh and rarely aged. Wine is almost always aged and then bottled. you will need to adapt.

But try what you have. You may develop flowers of wine, or vinegar, or it may work. But it can be a difficult and expensive lesson to find out you were wrong. My vote: buy some inexpensive carboys and age in them until your volumes are bigger.
 

Fox Squirrel Vin

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I use argon. My storage and fermentation tanks are converted stainless steel 60 liter milk cans the Amish use that are air tight with the lids on and work just like your tank does and I have the same issues. Argon is the heaviest of the inert gasses, heavier that nitrogen, the air you breathe is 1% argon, and it truly is a heavy gas that blankets really really well. It wont float off or mix with CO2 unless blown or "spilled" off. If the airlock pulls any air in from a change in barometric pressure it will not mix with the argon, it will float on top. It is a bit expensive but worth it over CO2 IMHO. CO2 is too reactive and can get absorbed in solution. CO2 however will displace Argon over time if there is any residual fermentation.

You can buy full tanks of Argon on Amazon, 40 cubic feet, they last a long time and it doesn't get any easier. Just swap them at your local industrial gas supplier when empty.
 
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sour_grapes

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1) I would, still, really like to hear from some lab tech somewhere - or some industry tech - not connected to winemaking. How do people do this in a lab ?

Okay, fine. When it was important to exclude air from our process in the lab, we evacuated the vessel down to a very low pressure, like 0.01% of an atmosphere. Then we backfilled with an inert gas.
 

Fox Squirrel Vin

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Argon
Argon is a true inert gas and has an atmospheric makeup of about 1%. With a molecular weight of 39.948 g/mol, it is a heavy gas that can be useful in wine production. The heavy molecular weight serves as a thick cover for blanketing wines in all areas of wine production. Argon is not soluble in wine and does not present the issue of dissolving, and therefore provides a longer-term blanket protecting the wine. According to research and a blind tasting panel, wines sparged with noble gases, such as argon, have improved shelf life, color, flavor, and aroma in comparison to those sparged with nitrogen.
 
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chonn

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Okay, fine. When it was important to exclude air from our process in the lab, we evacuated the vessel down to a very low pressure, like 0.01% of an atmosphere. Then we backfilled with an inert gas.

For a doofus like me, what does 0.01% of an atmosphere translate to in inches mercury ? I'm at sea level if that matters ... obviously a rough number is fine since here I am in my barn ...
 

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