I am still in my freshman year of homebrewing (and therefore paying a lot more attention to any brews I drink), and I also enjoy Unibroue, particular Trois Pistoles.
A couple of days ago, a friend of mine who I had turned on to Unibroue had picked up a variety pack of Unibroue and was showing me what he got. He said that he didn't like the lack of description of what he was getting, but based on what he had that I had given him from Unibroue, he took a chance on the variety pack.
I pointed out the small print towards the top of the label that describes what each beer was (Dark Ale, Red Ale, etc.) and I noticed that each one said "On Lees". So, this morning I googled "ale on lees".
The first thing listed was:
http://en.wikipedia.org/wiki/Unibroue
It says very early in the wikipost:
Most of Unibroue's beers are bottled "on the lees", or containing yeast sediment (or lees). This practice provides additional fermentation after bottling. The result is a beer which ages well if kept in the dark and unrefrigerated, and allows it to be shipped relatively cheaply to international markets. The yeast gives Unibroue beers a cloudy appearance and provides a characteristic element to the taste.
This agrees with the replies made to your original post two to three years ago. So nothing new really. Just further affirmation.
A link to homebrewtalk was the third item that came up on the google search and it was the first I clicked on.
One thing I saw as I was reading the replies was something about doing "a vertical" which now gives me something else to learn about. Again, I am a neophyte in the homebrew world.
Thank you for your post.