This comes from Raj Apte's site:
http://www2.parc.com/emdl/members/apte/ ... dale.shtml
Tank--------------------------------- Volume [L]--- O2 cc/L.year
Burgundy barrel -----------------------------------
300 ----
8.5
Rodenbach tank, wood, small --------------
12,000 ----
0.86
Rodenbach tank, wood, large --------------
20,000----
0.53
HDPE bucket -----------------------------------------
20----
220
Homebrew barrel -----------------------------------
40 ----
23
Glass carboy, 30cm vinyl immersion tube ------
20 ----
0.31
Glass carboy, silicone stopper -------------------
20 ----
17
Glass carboy, wood stopper ---------------------
20 ----
0.10
Given these numbers, I figured that the oxygen permeability was already built into this rig, since the container material is HDPE plastic. I figure with about 1/6th of the surface area still exposed, I should get close to the same permeability that a Burgundy Barrel gets. Between that micro oxygenation, and the macro oxygenation that it'll get from opening it every couple months for tasting, there should be plenty souring potential without the need for a wooden bung. If I see the souring is not going as planned, I can always pop one in later.