Unibroue beers are different. Brewed using an age-old process of in-bottle refermentation (with the exception of the U, U2, and La Bolduc), they are only partially filtered rather than totally filtered (which is the norm in todayÃÂ¹s beer industry). This means Unibroue beers keep all their protein and part of the yeast, producing a genuine upscale beer. These beers are on fresh lees. The lees deposit themselves at the bottom of the bottle as result of refermentation and natural carbonation. The process is the same as with champagne; except with champagne, the yeast is removed, while with Unibroue beers the lees are left in the bottle. This method gives a very particular taste to the beer and provides a natural source of vitamin B. Every single beer is brewed in one batch and is not water-softened.