ASK MAUREEN: Don’t Mistake Oxygen for Air; or UMAi Dry® for a Vacuum Bag

Everyday we receive emails and phone calls from customers asking for information, advice, reassurance.  Our front line “BagLady” Maureen provides knowledgeable answers in an ever-patient manner.  Her many years as a teacher are a tremendous asset.

In her honor, we introduce “ASK MAUREEN.”  This column will share Maureen’s answers to “life’s persistent questions.”

Today, a very, very common question:

  • I’m confused….does air get in or only out of the umai dry bags? what is “oxygen exchange”? J

Hello, J.

What you need to understand is that “air” is not the same as “oxygen.”  There are two reasons we emphasize that UMAi Dry® is oxygen-permeable:

1)  Oxygen helps produce good dry aged results.

2)  Oxygen prevents the scary anaerobic bacteria that can form within vacuum packaged food.

If you  are vacuum packaging food, you absolutely MUST remove all air or risk spoilage of the food or dangerous conditions within the bag.  UMAi Dry® does not pose that risk.

UMAi Dry® is applied with a vacuum sealer only to pull the bag into best contact with the moist surface of the meat—not to form a vacuum.  It is the bond that forms between that meat surface and UMAi Dry®  that is the key.  You only need 75-80% of the surface to bond with UMAi Dry® for consistent, reliable results.

Initially, UMAi Dry® will appear to hold a vacuum, meaning it keeps “air” out.  However, it allows oxygen molecules to pass through the material, just as it allows moisture to release.   It is like a membrane—protecting the meat, but not “suffocating” it. The enzymes in the meat get the oxygen they need to tenderize and improve the flavor during dry aging.

While you can breathe both oxygen and air, it is the oxygen that will keep you alive.  Similarly, while you can seal a piece of meat into both UMAi Dry® and a vacuum bag, it is the UMAi Dry® that allows the meat to transform like fine wine.

Hope this helps!

Maureen