Overview
The Knock Aergrind is a compact British hand grinder designed to pair with the AeroPress. The slim body fits inside the AeroPress plunger, creating an ultra-compact travel brewing kit. The 38mm Italmill steel burrs deliver excellent grind quality for its size, and the stepless adjustment provides precise control. The Knock brand has a devoted following for their distinctive design and quality burrs, and the Aergrind is their most travel-friendly offering. Build quality is excellent for the price, and grind quality rivals more expensive competitors.
The Knock Aergrind features a 38mm conical burr set, crafted from steel. Grind retention is approximately 0.1g — virtually zero retention, making it excellent for single dosing.
At $115, the Knock Aergrind is aimed at home baristas seeking a solid grinder without a premium price tag. Key workflow features include single-dose design (no hopper needed) and stepless grind adjustment for infinite precision. As a hand grinder, it's completely silent, portable, and gives you a meditative morning ritual.
The Knock Aergrind is weighing 0.4 kg, manufactured in United Kingdom. Its footprint measures 47 x 47 x 155 mm (W×D×H).
Pros & Cons
Pros
- Designed for single dosing — weigh your beans in, get precisely that amount out with minimal waste
- Stepless grind adjustment allows infinite precision for dialing in any coffee to perfection
- Near-zero retention (0.1g) means almost no stale grounds contaminating your next shot
- Completely silent operation — perfect for early mornings without waking the household
- Fully portable with no electricity required — great for travel and camping
- Excellent value for money — capable espresso grinding at an accessible price point
Cons
- Manual grinding requires physical effort — espresso-fine takes 30-60 seconds of turning
- Not practical for making multiple drinks back-to-back for guests
Full Specifications
| Brand | Knock |
|---|---|
| Model | Knock Aergrind |
| Category | Hand Grinder |
| Country of Origin | United Kingdom |
| Year Introduced | 2017 |
| Burr Size | 38 mm |
| Burr Material | Steel |
| Burr Type | 38mm conical |
| Retention | 0.1 g |
| Single Dose | Yes |
| Stepless Adjustment | Yes |
| Hopper Capacity | 25 g |
| Dimensions (W x D x H) | 47 x 47 x 155 mm |
| Weight | 0.4 kg (0.9 lbs) |
| MSRP | $115 |
Our Verdict
The Knock Aergrind is a hand grinder, which means it trades speed and convenience for portability, silence, and often better value per dollar of grind quality. In the $100–$250 range, hand grinders can match or exceed electric grinders costing twice as much in grind quality. This is the sweet spot for serious home baristas who don't mind the manual effort. If your daily routine involves 1-2 drinks and you enjoy a mindful morning ritual, this is an excellent option. For larger households or back-to-back drinks, consider an electric alternative.
Frequently Asked Questions
Can the Knock Aergrind grind fine enough for espresso?
Yes, the Knock Aergrind is capable of grinding fine enough for espresso. Its stepless adjustment allows you to dial in precisely for any coffee.
Is the Knock Aergrind good for single dosing?
Yes, the Knock Aergrind is designed for single dosing. With only 0.1g of retention, virtually all the coffee you put in comes out ground. Weigh your beans before grinding for the most consistent results.
How long does it take to grind espresso with the Knock Aergrind?
Grinding a single dose (18g) for espresso typically takes 30-60 seconds with the Knock Aergrind, depending on the bean and your desired fineness. It requires moderate physical effort. Most users find it a pleasant morning ritual, but if you make more than 2-3 drinks daily, consider an electric grinder.
How do I maintain the Knock Aergrind?
Clean out retained grounds after each use with a brush or bellows. Deep clean the burrs every 2-4 weeks by removing them and brushing away oil buildup. Hand grinders are easy to disassemble for cleaning. Never wash burrs with water.