. . . . .
View attachment 73905
* rubber corks are a good seal for a year or three (old rubber is hard)! This vacuum set up has been running for three months (Feb 11) and dropped from 17.5 in Hg to 9.5 (today),, ask me after a year how well cork and silicone and VacuVin check valve work for sealing a carboy. ,,, (no product in flask)
* driving force is part of storage, my feeling is CO
2 is our friend. A 6.5 gallon sister carboy to the above picture of degassed (able to maintain five inches Hg 30 minutes) cyser held a vacuum for a month, ,, likely still had some CO
2 bleeding out which equalized the vacuum. On the theory that the ullage is CO
2 at equal pressure (no driving force) I consider it safe storage until it is opened up. I kind laugh at folks that want squeaky clean wine with no gas. As noted in other threads I will vacuum cork (like industry folks) and leave some residual gas so the ullage can get filled up with CO
2.
* ALL CLOSURES WILL LEAK! some, a metal cap can be rated at 0.1 mg versus natural cork at 4 to. 8.0 mg oxygen per year. ,,, however we can assume the glass carboy or stainless tank walls don’t leak.
* for industrial scale wine the bottling operation is the biggest risk with a typical pick up of 4 to 8 mg O
2 per liter, racking to remove SO
2 can also be 4 to 8 mg, ,,, home wine makers have larger air to volume therefore we see high risk every time we open up a carboy.
* , , , , ,