Logs are “wet” when they are full of sap, the tree having been cut down. The kiln drying process is simply a speeded up and improved process of seasoning, whereby the sap/moisture is removed from the whole of the log.
Seasoning can take about 2 years and involves leaving the logs outside in a dry and draughty place. Kiln drying involves putting the logs into a hot and windy area and removing the moisture/humidity as the logs heat up.
Seasoning logs rarely get below 22% moisture as that is generally what the air humidity is, in the summer periods. Once logs are “dry” there is a very limited capacity for that log to take up moisture again through its entire thickness.
Whilst the outside may get wet (rain etc) that wetness would take years to return back to the centre of a log and would do so as the wood breaks down and slowly rots/biodegrades. That isn’t going to happen as its put onto your fire!
So, the reason why log stores are generally open fronted with slatted sides and a roof, is that the roof keeps the bulk water off, the slatted sides allow any dampness from rain to dry back off again.
With seasoned/unseasoned wood, if the moisture content is say 25/30%, as it does dry in the air, then that moisture has to escape, otherwise it will sit on the outside of the logs, causing mould/damp. That’s why you don’t want to dry wood inside your house! That moisture has to go somewhere!
When we reload a kiln with fresh, wet wood and then start the kiln up, the first few days there is the greatest amount of moisture being released from the logs. It can look like a tropical rainforest in there at first sometimes, the sir is really damp and there is water dripping off the roof as the hot air cools and drops the moisture!
Because our logs are much drier than seasoned, they wont “sweat” anywhere near as much as a normally seasoned log as the moisture content is so much lower. So you can leave them in the bags for a reasonable period of time, keeping the bag in a dry place, (under a tarpaulin and just off the ground is how I keep mine) or a log store is absolutely fine (and can look like a really nice feature of a garden – whereas my white bags have a limited aesthetic appeal!!
So if you want your kiln dried logs to look pretty, get a log store!!