What Makes Our Beer Special: Fermentation

With a few small exceptions that vast majority of the beer that’s made at the Monolith spends a significant amount of time in barrels. We typically use larger format barrels called puncheons that can be anywhere from 350 litres to 500 litres in size. We used to have from 700 litre puncheons but they were too darned big so we sold them to a friend. Finally we’ve got a handful of large wooden foeders, roughly 1300 litres in size. These are giant vessels that were previously used in Italy for wine production but we’ve done multiple batches of beer in them. Almost all of these vessels are made with French oak, the preferred type of wood due to its density and oxygen permeability. We’ve got a few other types of wooden barrels but those are rare because French oak is perfect for our methods.

For both spontaneous and mixed fermentation we put the wort into barrels very shortly after it’s inoculated. We then wait, and in the case of spontaneous fermentation we wait a long time.

It can be weeks until fermentation begins. Once it begins there’s an initial burst of activity and then a very long, slow fermentation that can literally last for years. One reason for this is our wort is very complex with lots of different types of sugars that require the action of multiple microorganisms often acting in concert to break it down into digestible chunks. We’re done some exciting research that shows just how complex this process is and how spontaneous fermentation is really a team effort. We evaluate the process of fermentation by doing chemical tests on the beer, but also by tasting it. Unlike normal beer that has a very predictable pattern of fermentation our methods are less predicable and require constant care and attention. We have over 400 puncheons in our brewery so that leads to a lot of tasting. Our brewers need to be on top of every single barrel so we know how to create the best possible blends.

We don’t ever use any barrels less than one year old in our blends and can often have beers that stay in barrel for up to four years. Our prized Homage to the Old Ones is made of all four year spontaneously fermented barrels – a real rarity. One thing that also keeps fermentation going long term is the slow ingress of oxygen into the barrel through the wood - French oak has the ideal permeability to keep fermentation going for years. Beer from different ages of barrels usually have different characteristics with the beer from younger barrels being brighter and fruiter than the savory and leathery older barrels. Ultimately these different characteristics are almost like the wide range of paints on a painter's palette, giving our brewers a wide range of flavors to use in their blends.