Diary of a Brewer: Trial Week Part 3

Link to Diary of a Brewer: Trail Week Part 2

I worked my final shift during my trial week at BrewDog last night, again working the night shift from 22:00 last night until 6:00 this morning. A very quiet shift in comparison to the others over the past week. I arrived to find that the afternoon shift had already mashed in on another batch of Paradox, transferred it to the copper and had already cleaned the mash tun (to my, and my body's, great delight).

Before we could begin the boil on this batch we had to make sure the original gravity was up at 1112.0, a formidable task considering the wort was resting at 1090 after the transfer. This rise in gravity is achieved by the addition of malt extract. Malt extract is used instead of malt because the weight of malt required to attain a gravity of 1112 would mean mashing with a liquor to malt ratio of ~1ml/g, far too close to the lower threshold where successful sugar extraction is not possible from the malt (see figure 4.14 contained in section 4.3.7 Mash thickness, extract yield and wort quality in 'Brewing Science and Practice'). The malt extract that we use comes in 25kg drums and is rated as 80% solids. These drums must be mixed with some of the heated wort in order to become viscous enough to be effectively mixed in with the contents of the copper. This process takes about 45 minutes per drum of extract, and after each drum is emptied a gravity reading must be taken to gauge if further extract is needed. Oscar added 225kg of extract to the wort last night, taking about 6 hours in total. During the time that Oscar was adding extract I was off performing the tank actions for the day and doing more PG checks to monitor the progress of tanks with active fermentation. About 2:00 in the morning when I had finished these tasks and Oscar was occupied with extract addition Stewart asked me to set up a tasting panel.

Tasting panels are routine tastings of the beer in the fermenters at various stages in their production. These stages include Fermentation, Cooling, Dry Hopping, Ageing and Filtration. Beer production is a very scientific process but sometimes it can only be classed as an art. These tasting panels are used to judge, based mostly on taste, if a beer is ready to be moved onto the next stage of production.

Stewart gave me a list of 9 FV that I was to collect samples from and label glasses with the FV number for tasting. This was an easy task until I tried to gather a sample from FV16 containing a 14% triple dry-hopped IPA named 'Anarchist Alchemist'. Because of the massive amount of hops added to this FV for dry hopping (something in the region of 400kg for a 100hl tank) the hops had blocked the port that I was using to collect a sample. Stewart helped me, very 'scientificly', remove the cover to the port and unblock the hops with a sanitised screwdriver. Keep in mind that located above the 1/4" port is 10,000 litres of liquid, weighing in at a very conveniently calculable 10 tons. When the port became unblocked a jet of hops and beer under enormous pressure came shooting out of the port covering both of us and nearly knocking the bucket out of my hands that I was using to frivolously manage the mess. We had our sample though!

The tasting panel was one of the most interesting things I have done during my trial week. Clearly being able to taste the subtle differences in these beers at various stages in production is a skill acquired over a long period of time. I suggested to Stewart that my ignorant input would likely be of no value to the company and so I simply tasted and discussed the beers with Stewart and Oscar rather than write my evaluation to be handed into the lab. As someone who had not tasted many beers that had just been dry-hopped, or had yeast contents that were off the charts, I was amazed that they were able to drawn any conclusions based on samples that tasted like dough or drain contents to the untrained pallet. Anarchist Alchemist tasted like you were eating a handful of hops (an experience only tangible if you have ever done so) due to the recent dry hopping, while the complexity of 'Paradox Isle of Arran' was amazing. A very humbling and gratifying experience.

And so in the early hours of the morning -- with brilliant sunshine basking all of Fraserburgh -- I finished my time at BrewDog, at least for now. I'll be in correspondence with Nikola to find out if I have the job and when I would start. I emailed James Watt and Stewart inviting both of them to the BrewDog tasting I mentioned in '24 Bottles of Beer on the Wall' before headed in the bed this morning. So here I sit, back at the Elizabethan Pub in Fraserburgh to pen the last of my 'Trial Week' entries in my journalling of my time at BrewDog. Jenny is driving up from St. Andrews as I write to spend the night and drive me home tomorrow morning.

My best estimate is that I lifted in the region of 10,000 kg of malt this week and aided in the production of approximately 45,000 bottles of beer. It has been an amazing, informative and tiring week. And I can only reflect on my time in Fraserburgh with the fondest of memories and the highest of expectations for the months (and possibly years) to come.