After about 20 brews in my Grainfather G30, I noticed quite a bit of brown staining in the bottom of the unit, particularly where the temperature probe and pump filter are sited. I assume this is due to some of the tannins in the boiling wort building up on the bottom of the unit. The staining appeared despite using Grainfather’s High Performance Cleaner. To be fair, I didn’t use it after every brew – more like after every 3-4 brews. It worked to a certain degree, but it didn’t get the unit back to “shiny” clean and over time the brown staining built up. It didn’t look nice! [Wish I had taken some before and after images now! Next time!]
Someone recommended cleaning with sodium percarbonate and it is relatively easy to get hold of. You can get hold of it here at the Malt Miller. This has worked an absolute treat. I put 3 small (washing powder) scoops in about 30L of water in the Grainfather. I heated it to about 60C. Then I left it to soak. It is an oxidising cleaner and after an hour, the brown staining just lifted off. I used the rough side of a plastic pan scourer to shift the more persistent spots.
I have also noticed a build of sediment on the walls of my Grainfather fermenters too. Particularly on the lower walls of the conical fermenters. So these got the sodium percarbonate treat too! It worked on these just well.
So this got me thinking that I should have a cleaning rota and once a month (say) the G30 and fermenters are deep cleaned with sodium percarbonate. The rest of the time they can just be washed out and sterilised. I don’t think it is necessary to use sodium percarbonate every time, but every 6-8 times (or roughly once a month) should do the trick.