Like many people who have an Hg One I tend to count the number of turns required to grind coffee and determine how much coffee is ground per turn. When I first got the machine on 6 July 2014 I calculated that it was grinding just over 300 mg/turn after I got it zeroed in. After running about 600 grams of instant rice through it it was up to a bit over 500 mg/turn. I ran a second batch of instant rice that brought it up to around 650 mg/turn. By December 2014 it was over 900mg/turn from daily use without rice, and for the next year tended to remain between 900mg to 1000mg. In late December I noticed the grind efficiency was dropping. Soon it was back down in the 650mg/turn range. I eventually realised that the problem was coffee residues on the burrs. There is a commercial burr cleaner, but it seemed to me to be the choice for electric grinders, not hand ones. I thought about alternatives, considering more instant rice, macaw pelleted food, Grape Nuts cereal, and then suddenly I hit upon what was clearly a good solution--Steel cut oatmeal, sometimes called Irish Oatmeal and sometimes called Scottish Oatmeal. I left the grind adjustment set for espresso and ran a heaping tablespoon of the oatmeal through the machine. The turning resistance was somewhat similar to coffee. The burrs looked clean, but I ran a second tablespoon through them. I took a brush and dusted off the oat flour dust from the top of the burrs, and also ran it around the underside. It is testimony to the LOW grinds retention of the Hg One was that the first coffee that came through showed only a few flecks of white! The efficiency was back in the 900mg to 1000 mg/turn range. It had the same feel it had had earlier before the grinding efficiency had begun to drop.

I ran the same type of oatmeal through my Pharos. That is much easier than tearing it apart to clean the burrs. Oatmeal seems to work just as well with the Pharos as with the Hg One.

I'm not sure that this would be a good idea with an electric grinder, but it surely works well for the Hg One and Pharos.

Just checked and I have run about 50Kg through the Pharos and the gm/turn is still consistent across all that coffee. I will file the steel cut oats as a cleaner if it does start to drop off. Good info for manual grinder cleaning without disassembly.

I read your post this evening and found your concept plausible. I checked my pantry and eureka, steel cut oats. I ran two tablespoons through and...yeah, lots of oat dust. I carefully transported the HG One to my garage and hit it with the air compressor. No more dust. I then ran a few tablespoons of beans through and back to the coffee bar. I will check the efficiency tomorrow morning. Nice hack, thanks for posting...