Big bubbles with degassing

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sampvt

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Ive just got a new set up. Its a 28 inhg vacuum pump (AC refrigeration type that pulls 3CFM and is as seen on U Tube) but when I pull a vacuum in either a bottle, carboy or demijohn, the small co2 bubbles come first then these enormous air bubbles appear. They are big from pea size up to ones that stretch right across the carboy or bottle.

Does anyone have any idea why they are appearing.
 

sour_grapes

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First, you should recognize that a small bubble at, say, 10 inHg can contain the same amount amount of gas a bubble that is 10x larger at 28 inHg. Ergo, there may not be any difference between the bubbles you see earlier and those you see later.

I have set up my pump so that I can "sample" the gas being expelled by the pump. By "sample," I mean "taste" with my mouth. Even in the late stages of degassing, where the bubbles are large, the exhaust gas tastes like CO2.
 

Johnd

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Ive just got a new set up. Its a 28 inhg vacuum pump (AC refrigeration type that pulls 3CFM and is as seen on U Tube) but when I pull a vacuum in either a bottle, carboy or demijohn, the small co2 bubbles come first then these enormous air bubbles appear. They are big from pea size up to ones that stretch right across the carboy or bottle.

Does anyone have any idea why they are appearing.
What Paul said is right on the mark. Get yourself a vacuum gage as discussed in the earlier post, so you can see what you're doing. When your wine is 72 degrees plus, and you hold a vacuum greater than 25 inHg for a few minutes after you switch the pump off, you're done.

Running it longer won't hurt, but that's the benchmark I use and it has never failed. Glad you finally found the right pump and took charge of your degassing woes!!!! You'll never look back!!
 

sampvt

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What Paul said is right on the mark. Get yourself a vacuum gage as discussed in the earlier post, so you can see what you're doing. When your wine is 72 degrees plus, and you hold a vacuum greater than 25 inHg for a few minutes after you switch the pump off, you're done.

Running it longer won't hurt, but that's the benchmark I use and it has never failed. Glad you finally found the right pump and took charge of your degassing woes!!!! You'll never look back!!
I have an in line gauge and on transfer from one carboy to the other (exactly the same setup as the allinone pump set up) under vacuum, the gauge sits at 25inhg. When the setup is just left to vacuum status, the gauge goes up to 28.5inhg.

The one thing I did notice was that the bubbles created by the transfer were very thick and filled nearly 1/3rd of the carboy. I had to stop the transfer and allow the bubbles to disappear before starting again. Ive transferred the mix into 1 gal demijohns and this is when I noticed the big bubbles. I was afraid I was getting some air in as the tubes I am using for this vacuum set up are smaller and maybe I am getting a bit of a leak but I cant see one. Ive done the test with water and dropped the joints into coloured water and no leaks appear. The only one I cant test is the pipe to pump one.
 

AZMDTed

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As a layman in bubbleology, I like to think of the big bubbles as a sign that I'm there, or nearly there, at degassed. My logic is that it is taking a greater vacuum to make a bubble (thus fewer but larger bubbles) and therefore there is not much CO2 left to bubble out. The head of bubbles you noticed at first was the release of the large quantity of CO2 that you still had and that's what should be expected. If you're not getting significant numbers of bubbles at the lower pressure then to me that means that there's not much gas left to pull out and you're done.

Of course, if I had a vacuum gauge I'd use that to make sure as John described.
 

sour_grapes

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I largely agree with Ted's take on this.

Frankly, I think there is a danger in over-degassing. Most wines have a little CO2 in them.
 

Johnd

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I largely agree with Ted's take on this.

Frankly, I think there is a danger in over-degassing. Most wines have a little CO2 in them.
And I wouldn't argue that point at all. The reality is, once those big bubbles start to show up, that's usually the point at which the vacuum is holding at 25inHg anyway. I was just looking for a reference point that was a little more definitive than "when the big bubbles start coming up". I envisioned ongoing discussions about what the size of the bubbles I consider to be big, the quantity of bubbles, the quality of the bubbles, etc.......... I guess I tend to overthink instead of oversimplify.

Great part of the whole thing is that sampvt has his degassing operation working and can thoroughly degas his wines in just a few minutes with no worries about whether or not he's done a sufficient job.
 

Arne

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I have set up my pump so that I can "sample" the gas being expelled by the pump. By "sample," I mean "taste" with my mouth. Even in the late stages of degassing, where the bubbles are large, the exhaust gas tastes like CO2.[/QUOTE]

You said you have a refrig. pump. It most likely is an oil type. Some of the oil will get into the exhaust. Might not want to be sampling it by tasting. Also, you might want to rig up a way for the exhaust to go outside. A fine oil mist can fill the room you are using an oil type in. I use the oil type, mainly because I had an old one laying around. It does fog the room and sometime I am going to get the exhaust outside. Arne.
 

sour_grapes

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I have set up my pump so that I can "sample" the gas being expelled by the pump. By "sample," I mean "taste" with my mouth. Even in the late stages of degassing, where the bubbles are large, the exhaust gas tastes like CO2.
You said you have a refrig. pump. It most likely is an oil type. Some of the oil will get into the exhaust. Might not want to be sampling it by tasting. Also, you might want to rig up a way for the exhaust to go outside. A fine oil mist can fill the room you are using an oil type in. I use the oil type, mainly because I had an old one laying around. It does fog the room and sometime I am going to get the exhaust outside. Arne.
Arne, you are confusing me and the OP. I have an oilless diaphragm pump. It is the OP that has the oil-sealed pump. I knew that he could not sample the gas himself; that is why I shared my experiences with him.
 

Arne

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Arne, you are confusing me and the OP. I have an oilless diaphragm pump. It is the OP that has the oil-sealed pump. I knew that he could not sample the gas himself; that is why I shared my experiences with him.
Be a lot easier if we were talkin face to face. Would keep some of the confusion out of here. Guess we have to do the best we can. :h Arne.
 

terrymck

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By "sample," I mean "taste" with my mouth. Even in the late stages of degassing, where the bubbles are large, the exhaust gas tastes like CO2.

Huh! CO2 is odorless and tasteless. Maybe what you are tasting is Carbonic Acid?
 

sour_grapes

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By "sample," I mean "taste" with my mouth. Even in the late stages of degassing, where the bubbles are large, the exhaust gas tastes like CO2.

Huh! CO2 is odorless and tasteless. Maybe what you are tasting is Carbonic Acid?
Yes, you are right, of course. Some fraction of the gas evolved by the wine is carbonic acid; also, as the CO2 dissolves into the fluids in my mouth and mucus membranes, it also forms some carbonic acid. It is a mildly acrid taste/feeling that I experience, not unlike club soda.
 

Alabadyin

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Related de-Gassing question

At what stage is it best to carry out de-gassing, or is it on going during the whole fermentation process?
 

AZMDTed

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At what stage is it best to carry out de-gassing, or is it on going during the whole fermentation process?
To a minor degree gas is escaping during the fermentation process. However, the term de-gassing is generally referring to a step after secondary fermentation and before adding any clearing agents. If the wine is not adequately rid of CO2 before adding the clearing agents the agents will tend to get caught up in suspension, riding on the CO2, and not be effective.

You will see at least two trains of thought on degassing. Most will talk about degassing as a step as I mentioned. They will use some form of stirring device or vacuum pump. In my experience the Wine Expert instructions on degassing are a joke as they call for about 4 minutes of stirring. My experience is that stirring alone takes almost an hour to effectively degas. Now I rack with the AllinOne pump, which gets a lot of gas out, I will still stir for about 20 minutes, then use the AllinOne headspace eliminator to try to draw out more CO2. After that I will add my Kmeta and clearing agents with a couple minutes of stirring.

The other school you will see on here will let the gas naturally dissipate through long term aging, and will treat clearing the same way, just let it fall on it's own time.

Either way, if you want good wine you have to get the gas out before you bottle. To me degassing is the biggest pain and problem in the whole kit winemaking effort. It has to be taken seriously.

I hope that helps.
 

Alibaba.41

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Hi guys it's the future talking😉
Two weeks ago I started two juices. I boosted the temperature in the room but unfortunately I overdid it it went up to 30 degrees Celsius I got a volcano in one carboy and the other one almost did it too. It's been now exactly two weeks since I've started this juices end I've vacuumed out pretty much all CO2 in one of them so much that I'm already at the point where I have big bubbles. Now two weeks I'm on the fence... rack, filter and bottle? Or to let it sit longer? These are only my 3rd and 4th batchs and the first two I didn't have my vacuum I'm still in learning slope..
 

Alibaba.41

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Not even the fastest winekit I have ever seen has you bottling at 4 weeks. It sounds like you should add some kmeta and let it rest for three or four weeks at least.
It's day 17 after purchase date. Starring SG 1.0997 and when I first racked on day 12 they were both at .994
 
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