I visited Mad Lab Distillery in Vancouver, BC, where they make whisky, vodka, gin, and raki. The distillery owner, Scott, was kind enough to explain their brewing and continuous fermentation process to me. So let’s get into their unique process!
Milling
They start the initial base spirit by milling 600kg of malt. They collect the milled grain in bags underneath the mill. It usually takes 3 hours to mill the malt.
Mashing
They collect the hot liquor for the mash in both a metal tank and the mashtun. During the distillations, they collect the used cooling water in the tank and re-use it for mashing in. They collect roughly 2000L of water, which is equivalent to two distillations’ worth of cooling water.
They heat the hot liquor to 78°C strike temperature and add about 1200L of hot liquor in the mashtun before mashing in. Pat the brewer and Scott, the owner of Mad Lab Distillery, manually carry each of the 24 bags of milled malt to the mashtun. The bags are poured into the opening hatch, which requires considerable effort. With the addition of the grain, the temperature will fall between 65-70°C. They add more water based on the consistency of the mash. If it appears too thick, they add approximately 600-800L of hot liquor. They run the rakes in the mash tun while vorlaughing to ensure thorough mixing and prevent heat stratification (development of relatively stable, warmer and colder layers within a body of water.)
The rakes and vorlauf run for half an hour, then the rakes are turned off while the vorlauf continues for another 15 minutes to clarify the wort further.
Wort Collection
After that they will start the sparge and the wort collection. Now this is where things get really interesting. The wort slowly travels from the offtake valve at the bottom of the mashtun and into the IBCs (intermediate bulk container), collecting a total of 1800L of wort.
You can see here that 3 IBCs are setup for the wort collection, and that all three bottom valves are connected by a hose. The hose from the mashtun leads into the top of IBC #1 only, so the wort that enters will put pressure on the fermenting wash beneath it. This wash will get pushed into IBC #2 which will push the fermenting wash in IBC #2 into IBC #3..
Since the wort enters IBC #1, this IBC gets diluted the most with wort. We can say that IBC #1 has the freshest or youngest wash in it, whereas IBC #3 has the oldest wash in it. This movement of the wort in the IBCs helps to restart the fermentation process inside all three of them. After 5-7 days of fermentation, IBC #1 will have fermented to 6%abv, while IBC #3 will have fermented to around 10%abv. The wash in IBC #1 takes longer to ferment since it has been diluted the most with the fresh wort.
Fermentation
Mad Lab Distillery uses a dry champagne yeast for fermentation. This type of yeast is highly durable and can ferment within 10-45°C, so it is stable within a pretty wide temperature range. It’s a good thing this yeast is so versatile because their IBCs are not temperature regulated. Remarkably, Mad Lab has used the same batch of yeast that they started with 4 years ago. They’ve only added additional yeast culture once in 4 years. Aside from that, the yeast culture they are using is basically the same yeast culture that they have been using since day number one, which is pretty crazy when you think about it.
Due to limited space, they distill IBC #3 first, which has fermented the most.
At the end of the work day they turn off the heat exchanger. As there is no cooling water available, the collected wort’s temperature is slightly warmer. However, this is not considered an issue since the IBCs are filled with a lot of cooled wort already. The cooled wort helps dissipate the heat from the warmer wort. They continue trickle collecting the wort into the IBC until a total of 2700L of wort is collected. This trickle collection process continues overnight and finishes at around 7am the next day, when the pump is turned on to maximize wort collection.
Draffing Out
After that it will be time to draff out. The draff is donated to a farmer who comes in about once a week. The IBCs will then be left to ferment for 5-7 days, before the distillation process begins. Scott’s distillation process here is extremely unique as he has no copper in his still at all. But I’ll save that distillation process for another post.
Watch it Below on YouTube
Leave a Comment