Double Fermentation - Confession

October 31, 2017

So why all the wobbly lines in the chart?


Well, on my double brew day anything that could go wrong, went wrong!


The first brew, Grapefruit Juice went swimmingly. All systems go, into the fermentation fridge. Quick rinse of the Grainfather and on with the Chocolate Porter.


95% through the boil I found the pump filter sitting in the sink in the kitchen. What to do? My hop additions were all in and I knew that using the pump to cool the wort was going to end in a blockage.


I decided that the best option was to stop the boil, dump the part boiled wort into the fermenter, clean out the Grainfather, put the pump filter back on, dump the part boiled wort back into the Grainfather and resume the boil. Job done!


Everything went swimmingly until I decided to force water through the pump outlet in the Grainfather to clean up the recirculating pipes. I put the nozzle of the hose over the pump outlet, switched the water on and pop! The Grainfather's silicon tube joining the pump to the up-pipe burst.


I had no spare, so repair wasn't an option. So I put the fermenter into a plastic bin and  immersed the whole thing in circulating cold water. Bringing the temperature down to about 25 degrees. Got the Porter into the fermentation fridge, connected up MyBrewbot, set the temperature to 22 degrees and let the wort cool down to pitching temperature. When it had cooled I took the fermenter out and oxygenated the wort, pitched the yeast and put the whole thing back into the fermentation fridge.4 days later I dry hopped. This accounts for all the temperature chatter in the early part of the chart.


Then I went away for a week at the seaside. When I arrived at the house, about 120 miles away from home, and took a look at MyBrewbot temperature data I was horrified to see that the temperature was pretty erratic. I wondered what was causing this and soon realised that when I had put the Porter back into the fermentation fridge I hadn't put the temperature probe back into the thermowell. I'd left it on the top of the fermenting vessel. You can see the difference in the target and porter lines on the chart.


Since this was the fermentation temperature control probe the temperature wobbled about from then on. It wasn't insulated so was exposed to a combination of the heat from the SS Brewtech vessel and the ambient air temperature. Not the usual rock solid MyBrewbot control


When I got back from my week at the seaside it was time to move to secondary. I did this on the Saturday morning before going off to Birmingham for my youngest son's stag weekend. Whilst there a fuse blew in the house and all of the electrics went down. Whatever could go wrong went wrong.


I have since tried both beers and they are surprisingly good, seeing what they went through in their production process.




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