Well, I’ve finally bit the bullet and decided to brew. I know the software was far from complete but the hardware was ready to go and as they say “you learn from your mistakes”. So here goes.
If this brew-day was filmed, I reckon it would have made a great disaster movie. You know the script. Things begin calmly, the world is good. Then there’s a small problem but it seems under control. Then another problem unexpectedly arises which compounds the first problem. Then things escalate and it all goes open loop. Everything that can go wrong does, it seems like the end of the world. But then the hero arrives at the last minute and figures out how to save the day. The world is right again. That was my first brew day!
The whole process was semi-automatic. Driven from the command-line step by step. I don’t trust my code enough to fire and forget just yet.
The Recipe – My Little Dead Pony
This recipe was inspired by Brew Dog’s Dead Pony Pale Ale. I tweaked a few quantities, mainly increases in malt and also hop quantities during the boil. I felt Brew Dogs use of hops was a bit stingy (at least during the boil).
|Maris Otter Pale Ale||4 Kg|
|Pale Crystal Malt||0.3 Kg|
|Citra Hops (Boil 60 mins)||20 g|
|Simcoe Hops (Boil 60 mins)||20 g|
|Citra Hops (Boil 30 mins)||10 g|
|Simcoe Hops (Boil 30 mins)||10 g|
|Citra Hops (Dry Hop 4 days)||75 g|
|Mosaic Hops (Dry Hop 4 days)||50 g|
|Simcoe Hops (Dry Hop 4 days)||50 g|
|WhiteLabs California Ale Yeast||
Before starting I manually ran Starsan through all pipes. Paying particular attention to the route between kettle and fermenter via the chiller.
The intention of the mash was to recirculate at 65C for 75 mins. This slightly lower temperarture and longer time is from Brewdog’s recipe published in “DIY Dog”.
This had to be stopped after 15 mins because the mash was sitting at only 60C. I manually had to switch on the heater because the kettle was only at 56C and the wort was not very sweet.
The grain bed also became very dry so I pumped all of the kettle contents into the mash. Had to override pump because it was pumping too often. Also had to manually open the mash inlet valve.
The kettle was at 70C but the mash was only 57C. I notice that the element was scorched. I don’t think it was running dry but something was seriously wrong.
So I pumped all the wort from the mash tun back into the kettle. Heated it to 80C and back to the mash tun again. Did another cycle at 75C.
The wort gravity was low and very thin to taste. It was clear that the sugars were not fully extracted. So I essential did an immersion mash until the OG was reached and not unsurprisingly tasted nice and sweet. The total mash time was very long indeed but I felt it was more important to extract the sugars than to stop the mash based upon time.
The chill command began fine. The cold inlet opened and flowed through the chiller into the drain. Then the other valves opened and the pump switched on to transfer the wort from the kettle to the fermenter.
The fermenter temperature appeard to be down to 16C, so I pitched the yeast. It was only then that I noticed that the cold input value to the chiller has closed. Refreshing the display showed that the fermenter temperature was sitting at 37C!
I tried to pump cold water from kettle but couldn’t. I though there was a blockage so I had to connect the mains cold supply directly to the fermenter and run the coil output to a big bucket. Eventually I got the temp below 20C.
- Initial ferment algorithm seemed to go well. I awoke at 0530 and checked the temp – all was well so I went back to bed. Got up at 0730 and the kettle was boiling and the ferment temp was back up at 30C.
- I though I fixed some issues but debugging was impossible since the system was live. I had hoped it was fixed but not yet. The temp kept on going through the roof. Eventually I spotted my stupid mistake. The control algorithm was monitoring the mash thermometer instead of the one in the fermenter – doh! After fixing that the ferment temperature stabilized at the desired temp of 19.5C.
- Fermentation lasted a couple of weeks. After which the gravity reduced from 1050 to 1012. Giving a final ABV of 5.0%.
It was an eventful mash process but the wort tasted good in the end nevertheless.
The fermentation temperature was initially too high but I got it down from 33C to 21C in 30 mins. Not ideal but I think within limits.
I’ve got bugs to fix:
- Recirculating mash is currently flawed and needs further development.
- Chill valve is closing prematurely.
- An air lock develops sometimes when regulating the ferment temperature