Fully Refurbished like New - When it comes to grind retention, the M7D is among the best in its class. It retains just 4.5 grams on average, so you’ll never have to purge stale grounds for more than a second before getting fresh coffee. Espresso grinders with a low grind retention are proficient at single dosing. As with most grinders, you will find that grind times are longer when single dosing, with a 20g dose taking around 20 seconds. But the shots speak for themselves: they’re delicious.