Another MityVac question

[Mark]

This is the first time I've tried the MityVac. Just before the degassing step on a WE Selection Int'l Aussie Cab (when I knew it'd be full of gas), I tried the MityVac and got the usual foam. So I degassed with the drill-mounted MixStir first (I know... spoon bad, drill good!) then tried to finish up with the MityVac. This time I got only the larger bubbles I read about, but from the sides and not the center, and no foam.

Is this CO2? Should I continue untilit can't hold a vacuum, or is this just a normal sign of good degassing? This promises to be a good wine so I don't want to mess it up.

 

[Wade E]

I usually g until I can hold about 15 " of vac. Some wines are very
easy to degas and the drill mounted takes care of almost all of it. It
sounds like you had an easy one this time. There have been some where
Ive had to use it for days to get it degassed even after using the
drill mounted stirrer.

 

[Mark]

Here's a better picture...

Wade, are you saying this looks like I'm degassed, or should I Mityvac until it'll hold a vacuum?

 

[Wade E]

Sometimes you can not get a good seal with what we use. Did you pump it till it reached 20 or 25?

 

[Mark]

I took it up to 15, and the greater the vacuum the more it bubbled. I held the hose connector tight to the bung so I know the vacuum was dropping due to the bubbles, not leakage.

 

[Wade E]

I can always hold around 10"-15" when Im done degassing.

 

[Mark]

Thanks! I'll try it for a while tonight and see what happens...

 

[Mark]

I tried the Mityvac last night. 5in pulled nothing, 10 started pulling some gas out, 15 pulled a small but constant flow of gas. 30 minutes later it was down to almost nothing at 15in. (Didn't have enough headspace to go up to 20in.) So I guess I did a fairly decent job with the Mixstir, and a lot of the remaining gas left on its own between Saturday morning and Monday night. If I would have kept with the Mityvac on Saturday it would've pulled it out. So I'm convinced that vacuum degassing is a good extra step (especially if it's a stubborn one!). Thanks again, Wade!

 

[Dean]

you might want to siphon some of the wine out to create a much larger surface area. The larger the surface area, the greater the impact of the vacuum! In your photos, you have less than 2" surface area to expose the pressure differential to. If you bring that wine down to the shoulders, you will expose a whole lot more of it and attain much greater degassing ability.

 

[Mark]

Yeh, I thought of that too, but figured I'd wait until this weekend when it gets racked. There'll be more headspace (before topping up), and I'd avoid taking any chances with contamination with the extra transfers. I think I got most of the gas out already so waiting an extra few days shouldn't hurt. Thanks!