# Retention after cleaning/grind-size change on Smart Grinder Pro



## filthynines (May 2, 2016)

Over a year into my use of this grinder I've now noticed that there is significant retention after both cleaning and a change of grind setting, to the tune of 1g-1.5g.

A few times this week I've gone from setting 2/3 to setting 50 to go from espresso to French press and back again. My espresso dose after grinding for French press is always underdosed. Worth keeping an eye on if you use just this grinder for all of your coffee.


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## ajohn (Sep 23, 2017)

I had a problem with the grinder on me BE after thorough cleaning. Several kg of beans most oily and it had ground them perfectly, no clumping or any other problems. It just needed occasional tweaks to the timer to maintain the 9.3g dose I was using.

The main reason for cleaning was to check the part that sweeps the grinds out of the grind chamber under the burrs. I'd seen a video on the SGP showing an earlier version that used a plastic part to do the sweeping and they needed periodic replacement due to the tips wearing. I also have a SGP and noticed that it had been updated - plastic with metal to do the sweeping. My BE has the same part so these have also been updated. Then came the problem. Same beans and it started clumping and I had to use a coarser grind settings. Taste and tamping changed due I think to there being a lot of finer grinds in it even though I was using a coarser setting than i ever had before.

Bit of a mystery because when I first bought the machine I didn't have any problems at all. I did what it suggested in the manual - on the BE start at a grind setting of 8 and then tune. Eventually I got what I wanted but things did seem pretty inconsistent initially. Then different beans usually using a grind setting of 4, 5,6 or 7. Most often 5 or 6. I've mostly drunk oily dark roasted monsooned malabar. All I found with that is that initially the grind timer needed increasing very slightly from time to time but after a while the adjustment might go either way but was always very small. The joys of 9.3g, If it shifts by 0.2 i can taste it.

What I suspect is going on is that the grinders are designed to trap some grinds and it's best to let them do just that. As it's eventually highly compacted under the sweeper it doesn't contaminate different beans. All I've found I need to do to be sure is run 20g of a new bean through it. I usually drink both. The first 10 might taste a touch different but I wouldn't want to swear to it. That could just be down to a light coating on the burrs but the finish on those compared with some others is so high that they hardly retain any at all.

Waste of an SGP but all I usually use that for is weighing beans in when I am trying a new bean. What comes out is generally within 0.1g of what went in or the same. I might see a bit more at times but it's still a very small change. I bought a refurbished one so it came complete with some ones grinds already compacted in. I just brushed the burrs over.








I haven't "recompacted" the grinder in the BE yet as I damaged the fibre washer a bit getting it out and am waiting for a new one to arrive. Waiting too long. I tried to order it from the people who appear to stock parts but Sage have told them they want to sell spares. The other company can provide part numbers though if needed for more serious bits.

What I can't make my mind up about is what bean to use initially. I used monsooned early on and a lot of it since. The roast I use is so oily the beans can stick to the side of the bean can especially when they have been in it for a while. I also have to wash the hopper every 500g or so otherwise beans can fail to get down to the burrs when the hopper is low. The first beans might have been a pretty easy to use commercial blend. Not sure. When I fit the new washer I'm going to start at an espresso setting that is coarser than one I am likely to use as that is what I effectively did when I first bought the machine.

I wouldn't let this retention aspect put people off because they can produce very good grinds. Some can't. Ok some huge grinder with massive burrs may have a different taste profile but it can have other problems as well.

Forgot to add. Previously the only time the grinder has taken a while to settle down again is after a grind setting change and and a different bean. That's usually bean back to monsooned and the grind timer might need a tweak every day for a while slowly stretching out.

John

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