Not too long ago someone offered to send me some Coffeeduck Espresso adapters since they did not work in his machine. Being a coffee gadget fan I gladly accepted and came in the mail today as promised. My Nespresso machine is an older style Krups/Nespresso type 583 so I knew I would have to modify the design of the adapter to get it to work in my unit. the thick center post in the center of the adapter is exactly where my machine pierces the capsule with a spike. The adapter simply won't fit till the cap is cut off the top of the stem and some trimming takes place. The white ring (shown in the top left photo) blocks those little holes which is where the water enters on newer Nespresso designs than mine.
The shot is 6g of a 10 days post roast blend designed with espresso in mind ground with my Baratza Virtuoso conical burr grinder. The upper left and middle photos show an 18 second single shot with maybe 6g coffee grounds in the Coffeeduck adapter. I did not try cramming more in there since the extraction with the Nespresso machine came out in just drops to start till a slow stream started to flow at 11 seconds. Any significantly finer grind or extra tamping to pack in another gram most likely would choke the machine. I expect playing with the grinder settings and tamping inside the capsule would improve the results, but not to the point where it will produce what My control machine, the Krups Type 882 creates (the shot in the upper right photo). The Coffeeduck shot tastes OK, but misses the control shot by a mile in terms of flavor intensity.
The control shot on the top right is 14g of the same espresso blend pulled on a Krups Compact Type 882. Now the Krups 882 features a plated brass group head and portafilter connecting to a stainless steel boiler with the same 41 watt Ukla pump used by Ascaso, Rancillo Silvia (a nice machine!), and other popular vibe pump espresso machines - not bad specs really. Admittedly the Krups has a warm place in my heart but I mention these specs only to qualify what you see in the photos. The Krups/Nespresso Type 583 is going up against a wolf in sheep's clothing and clearly is out of it's element without the magic created by the retail capsule's design and precise grinding and packing of the coffee.
The bottom left and middle photos are some I posted a while ago when refilling an empty Nespresso capsule and covering the end with foil. The coffee was a fresh espresso blend too. Not apples to apples with the coffee but of most importance is that the freshness was similar for each coffee when the photos were originally taken.
The photo on the bottom right is a shot from the purple Nespresso Arpeggio capsule, so another control shot. The Nespresso is nice when convenience matters.
Nespresso machines do a great job using Nespresso capsules, a decent job when refilling the empty Nespresso capsule, and a sub-par job using the Coffee Duck for Nespresso. I cannot say for certain a newer (but not very new, since those machines have been "fixed" and most plastic body adapters can easily get jammed in the capsule holder) would do a better job but I doubt it. The pressure developed was obvious, the beans were capable, and the Virtuoso proves with the control shot it is also up to the challenge. My take on the CoffeeDuck for Nespresso? These are not worth the expense or trouble.