The Rancilio Rocky is a fan-favourite grinder for the budget-conscious home espresso enthusiast. It's also a tried and tested classic that has been around for many years. In fact, it's one of our top picks for one of the most affordable espresso-capable coffee electric grinders. The Rocky is a product that offers great value to the thrifty but serious home barista, and we're excited to bring in a new accessory that extends the machine's versatility even further.

When it comes to grinding for espresso, retention is one of your main enemies. It's no secret that espresso is a particularly sensitive method of brewing coffee, and a few grams of old coffee hiding in your grinder and making it into your next shot can significantly alter the flavour profile. Equally underdosing by even just a gram can yield a very different shot. Given the popularity of the Rocky amongst our customers we jumped at a recent opportunity to help them reduce this problem of retention.

These simple 3D-printed bellows are designed especially for your beloved Rancilio Rocky grinder. By placing these bellows atop the Rocky's hopper, you can push out the remnants of previous grinds each time you dose coffee. In fact, the creator of these bellows also suggests using it during grinding to keep the Rocky's output evenly distributed (from our testing, we'd tend to agree - see below). Reducing both retention and clumping at once is a seriously appealing prospect for the home barista. If you're regularly flushing out your grinder with the bellows, you'll also find there's less to clean when maintenance time comes around, keeping the chore to a minimum, and your grinder in great shape.

These bellows also make the Rocky a viable grinder for single-dosing. If you enjoy this exploratory approach to coffee — jumping between different beans and experimenting with brewing their unique flavours — you'll find that flushing the grinder as you dose each shot enables the Rocky to be a perfectly effective single-dose grinder, something you may only expect from a higher-end grinder.

In our testing, we found these bellows to perform exactly as we'd want them to. Working with fast, shallow pumps* works best, and brings a significant reduction in the Rocky's retention. While it's impossible to completely eliminate retention, we managed to bring it down to much less than a gram, representing a big improvement over most domestic espresso grinders typical retention, including the Rocky.

A remarkably simple accessory, these bellows are a great companion to your Rancilio Rocky espresso grinder. They're an effective, durable and high-quality accessory for their price, and will add to the value and functionality of your trusty Rocky grinder.

* pumping too hard or too deep may unseat the bellows and also is not as effective. We'd recommend sticking to short, shallow pumps.

Rancilio Rocky Bellows specifications

• Diameter: ~12cm
• Height: ~5cm
• Weight: ~35g
• Material: Thermoplastic polyurethane

Please note that the bellows work with the hopper lid that comes with your Rancilio Rocky. A lid is not included with the bellows.