Rules for degassing...

[winesnob]

I couldn't find a separate discussion degassing wines, so I'll start one.

I've read about different methods of degassing and at different stages. I've read somewhere about degassing before bulk aging because the time the wine is spent in the bulk aging, does not degass the wine automatically. In both my kits (Dry Creek Chard. and my Santa Ynez Syrah), I've stirred the crap out of it prior to and after adding the fining agents, but there is still gas in there.

I've read that people use the Mity Vac and Acu-vin/vac, a whipping tool attached to a drill and even a food saver. After reading this, I decided to give my food saver a try. I first tried it on my Chardonnay I have in a plastic carboy in it's clarifying stage...OOPS don't try that!!! Make sure you have it in a glass carboy. I stopped it just in time. I hope you know what was about to happen...
I then tried it on my Syrah in my glass carboy. I started seeing bubbles forming. I've been doing this for a couple of days ( a few times per day) and will keep doing it until there are no more bubbles. I'll have to rack my Chard. off to a glass carboy and leave my plastic carboys to the secondary fermentation.

 

[masta]

My rules are:


1. Save yourself lots of grief and effort and buy a drill mounted stirrer like a Fizz-X or Mix-Stir then follow the instructions below and you should never have an issue with bottling wine that still has dissolved CO2 in it.


2. Don't be in hurry to start the stabilizing/fining stage as I believe this why some folks have trouble degassing and experience the volcano effect when using a drill mounted stirrer. I choose to let the wine tell me when it is ready to be checked for final SG and degassed by action in the airlock and foam or bubbles on top of the wine in the carboy. Letting the wine sit longer before attempting to degas allows the wine to complete fermentation and more importantly start to degas on it's own.


Just a quick redux of the stirring issue for my (Winexpert) kits:


<UL>
<LI>If you've fermented at the right starting volume, the right temperature, and you've achieved the recommended specific gravity levels, then you'll be able to stir the wine to de-gas within the time-frames specified in the instructions.

<LI>If the wine was started at anything other than the full 6 US-gallons (23 litres) or it was fermented cooler than 68 F, or if your gravity readings were not at or below the recommended levels when you did the process, you will not experience consistent success.
<LI>You only need to stir a Winexpert kit four times.

<UL>
<LI>On day one, you have to beat the snot out of the must to mix it properly. A good, arm-cracking one minute stir to froth it up and mix the juice and water will get you off to a good start and a thorough fermentation
<LI>On fining/stabilising day, after you've double-checked the SG, then you can first stir the kit without adding anything--and without racking it off the sediment! (Unless it's a Crushendo kit, but that's covered in the instructions--no racking for any other kit. If you choose to rack it, you will not experience consistent results. This first stirring will be to greatly de-gas the wine, prior to adding any of the fining agents or stablisers. Beat the hell out of it, for one full minute. Use a watch or clock--one minute is a lot longer than most people think. If you can scractch your head with your stirring hand after that one minute, you haven't stirred hard enough. It should be an all-out blizzard of effort that costs you all of your strength, and you should see spots in front of your eyes (see why I tell people to buy a drill-mounted stirring whip?)
<LI>Add the sorbate and the sulphite, and stir again, for one full minute. This time you may break one or two small bones in your stirring arm, but don't slow down--if anything, stir harder.

<LI>Add the fining agent and the F-Pack (if the kit has one) and stir for one more full minute. Have the paramedics standing by with a bag of ice to carry your stirring arm to the hospital where it can be re-attached. Top up with water and call it a day.
</LI>[/list]</LI>[/list]


Now, if you have fizzy wine after this regimen, you don't have a stirring issue. You have eiither got an incomplete or ongoing fermentation, or you're mistaking foam for fizz, or you may have an inicipient lactic acid bacterial infection that is making a bit of CO2 in the wine.

The amount of stirring described will reduce SO2 slightly in the kit: however, the amount it is reduced by is minimal, because rather than uptaking oxygen during this process, the wine out-gasses CO2, which actually scrubs some of the oxygen out of the wine.

If you stir at a time when the wine is not saturated with CO2, you may experience reduced SO2 and potentially expose the wine to oxidation. But then, why are you stirring wine if it's not fizzy?

Hope this helps outl

Tim Vandergrift
Technical Services Manager, Winexpert Limited.

 

[winesnob]

Masta, is that the only stirring/degassing you do (before and after adding the fining agent? That's pretty sweet if that is the only time you do it.

Thanks,
Scott

 

[masta]

Yes that is correct...three stirs and if you use a drill mounted stirrer I would estimate it takes 2 mins total.


A few more rules:


3. The temperature of the wine you are trying to degasshould be at least 70 degrees since the cooler a liquid is the more dissolved gas it can hold (this is why you chill beer before force carbonating).


4. Getting foam when stirring your wine does not mean it still has gas in it. Some wines foam more than others anddon't use the foaming as a guide todegassing. Follow the technique and it will work everytime!


I searched and found some pictures to show the efficiency of a drill mounted stirrer, I seriously doubtyou could do with a spoon or paddle by hand:


This is my mix stir in action in a 6 gallon carboy full of water:


Medium speed to get a good vortex (F3 Tornado) ...kinda cool!

High speed (F5 Tornado) and this will drive off any CO2 but be careful!

 

[winesnob]

Very impressive!! Is that grain alcohol

When racking from the primary, the amount of juice tends to be less than 6 gallons (enough for the gel fining solution). Do I have to take out more juice to kick off the medium size tornado without fear of overflowing?

 

[masta]

I never have to remove any volume from the secondary carboy to degas but if you find it quite full and not enough room to stir without making mess just remove some of the wine and then degas. The small amount you removed can be put into any clean and sanitized container that has a lid and give it a good shake to force out the gas and then return to the carboy before stabilizing and fining.

 

[Funky Fish]

My two cents: You do not want to form a vortex (tornado) in your wine when degassing. Why? The CO2 is driven out of suspensionat the low pressure areas behind the blades of the mix-stir. The best way to maximize the low pressure area is then the blade is moving at a different speed than the liquid. If you are mixing at a near-constant speed in one direction to form a vortex, then that means the liquid is moving at a speed closer to the mix-stir's speed. Which means that you are getting less pressure differential accross the blade (and less CO2 out).


So even the the vortex looks cool, it's not as effective for driving off CO2 (and may even aerate the wine, which is not desirable).

 

[masta]

Yup...you are 100% correct funky fish and the vortex was only meant to show how well the drill mounted stirrer works.

Quick shorts bursts and reversing directions works the best (even thought the manufacturer says not too)