Pompeyexile The best way to think about it is, assuming a grinder that’s done at least 4 shots after any cleaning and not been puffed, or slapped about.
- You grind 18.10g and get 17.95 out = 0.15g discrepancy
- You grind 18.10g and get 18. 08g out = 0.20g discrepancy
- You grind 18.05g and get 18.15 out = 0.1g discrepancy
This is typically what I see with medium to medium light roast bean at espresso grind. Variations so small they have no effect on the extraction or taste within the cup.
I talked about an “Exchange” figure, which I directly measured on the Niche, from memory I think it was 0.3g. Please note if Eureka quote an exchange figure on their new grinder, it has to be an estimated one, there being no way to measure it. I believe retention was around 0.7g. The total retention sets the maximum exchange weight that’s possible, for obvious reasons.
I’m going to introduce 1 new concept here which I think I kept out of the review to keep it simple. “Retention” is of two types. Static and Dynamic..Static is the stuff that will never move and dynamic is the stuff capable of participating in “Exchange”
Keeping all the above in mind and the fact that only a portion of coffee available for exchange, actually does exchange, which is a reasonable assumption. In every 18g grind, you might get up to 0.3 g of coffee from the previous grind, it can of course be much less..
All using the puffer does is bring out that part of the coffee that would participate in exchange for the next grind (the dynamic portion of retained grinds)…so if for example you got 0.4g out, you are simply going to lower the grind consistency by an extra 0.1g and be puffing again to get all the coffee out….you will be forced to use the puffer all the time in your workflow.
All this faff for eliminating up to a maximum of 0.3g of exchange, which you see any effect from, in extraction or in the cup. A single coffee bean only weighs about 0.8g!!
There are a few things people do with the Niche which is pointless and counterproductive
- Banging the lid, the grinder, or rocking it to get more out
- Frequently calibrating, which is absolutely pointless, you do not need to calibrate after cleaning, unless you accidentally moved the black clicky ring with the grind indicator on it.