Oaking rum chemical reaction?

[liquidart]

So I made a few batches of pugirum put in 5l demijohn to age at approx 70%. I changed my yeast to the safale US05 this batch an switched oak to used rum chips so I altered two variables.
I pop the top once a week to air and see where the aroma is headed and on week 5 aftermixing it appeared to have a layer of smoke or a co2 layer maybe? Smelt slightly heady to me and was pressurized as the cork nearly shot out I blew away the gas an checked the next day it didn't reoccur an smelt amazing again ( pressure has built but no more smokey looking stuff)
So I thought I'd ask on here an see if any of you guys may have experienced this phenomenon or if u know what fraction reaction may have caused this or if it must be this new oak.

Anyway any help would be awesome I'm not ditching it I just like to understand as much as I can.

[pulsetech]

Leave the lid off and cover with a coffee filter and rubber band. That bad stuff need to evaporate off and get out. It needs to breath like it would in an oak barrel

[liquidart]

Ok will try that method i gave it a week of airing as a white dog but wasn't certain if too much oxidisation too quickly would negatively affect it during the oaking stage.

[bt1]

You can air em for weeks except in summer=evaporation issues...bloody pissed airing fairies no good and hard to catch

bt1