Grinding Coffee – The Unsung Craft Behind Every Great Cup.
Why the Grind Matters More Than You Might Think
In the world of coffee, the difference between a silky espresso and a sour, watery shot often boils down to a single factor: grind size. When beans are ground you expose surface area to water. Too much surface (a very fine grind) leads to over‑extraction and bitterness; too little surface (a coarse grind) produces under‑extraction, acidity and a thin body. Nail the grind, and you can dial in flavour without changing beans, water or equipment.
The Spectrum of Grind Sizes
Each brewing method has its own sweet spot.
Extra‑coarse – perfect for cold‑brew that steeps for 24‑48 hours.
Coarse – ideal for a French press or percolator.
Medium‑coarse – works beautifully with a Chemex or Clever dripper.
Medium – the go‑to for most drip coffee makers.
Medium‑fine – the standard for an Aeropress (standard recipe).
Fine – the essential setting for a traditional espresso shot.
Extra‑fine – reserved for Turkish coffee, where the grind is so fine that the particles stay suspended in the water, creating a thick, muddy texture rather than a clear solution.
Understanding where your favourite method sits on this scale lets you set the grinder with confidence, rather than guessing.
Burr vs. Blade – Which Grinder Deserves a Place on Your Counter?
Blade grinders chop beans haphazardly, creating a mixture of fine powder and chunky bits. The friction they generate can warm the beans, subtly altering flavour, and they only offer a crude “coarse/fine” switch.
Conical or flat burr grinders, on the other hand, crush beans between two precisely machined surfaces. The result is a uniform particle size, minimal heat, and micrometre‑level adjustments. For any café, hotel lounge or restaurant that prides itself on flavour consistency, a quality burr grinder is non‑negotiable.
Optimising Your Grind – Practical Tips
Weigh Before You Grind – Use a digital scale (accurate to 0.1 g) to measure your beans. A consistent dose removes one of the biggest variables.
Mind Grind Retention – Burr grinders hold a small amount of coffee in the chute. Empty the retention chamber after each grind to avoid stale residue mixing with fresh grounds.
Tame Static – Fine settings can cause grounds to cling to the hopper. A quick puff of air or a brief pause before dispensing helps.
Watch Temperature – Grinding large batches can raise the grinder’s temperature, subtly affecting extraction. Let the grinder rest for a minute after grinding a sizeable batch (e.g., roughly 200 g) to allow any heat build up to dissipate; adjust the interval based on your specific grinder’s behaviour.
Calibrate Regularly – Run a test grind, weigh the output and compare it to the input. Adjust the burr gap until the weight matches within half a gram.
A Typical Café Grinding Workflow
Pre‑shift – Warm the grinder with a short empty cycle, check burr alignment and give the chute a quick brush‑down.
Durng service – For espresso, adopt a single‑dose approach: grind exactly the amount needed for each shot (usually 18‑20 g). For batch‑brew methods such as French press, grind the whole batch once and store it in an airtight container for up to 24 hours.
Post‑shift – Brush out the burrs and hopper, then run a cleaning tablet or a small amount of rice (if the manufacturer permits) to strip away oil build‑up.
Troubleshooting the Common Issues
Bitter, harsh espresso – The grind is often too fine, leading to over‑extraction, but also check water temperature, dose, tamp pressure, and brew time.
Sour, thin coffee – The grind is frequently too coarse, causing under‑extraction, though low water temperature or short brew time can also contribute.
Channelled extraction – Uneven particle size or clogged burrs can cause water to carve pathways. Clean the burrs, recalibrate and ensure an even tamp pressure.
Grounds clumping together – Excess static or humidity are the usual culprits. Reduce humidity in the storage area or use an anti‑static brush.
Motor humming with no output – A jam or beans stuck in the chute. Power off, disassemble according to the manual and clear the blockage.
Taking It a Step Further – Advanced Techniques
High‑end grinders now let you set separate intake and exit burr gaps, giving ultra‑fine control for espresso while keeping a slightly coarser intake for smoother bean flow. Some models also store multiple micro‑adjustment profiles that can be recalled with a single button – perfect for venues serving a range of beans. The most sophisticated units even feature built‑in load cells that weigh the grounds as they exit, delivering near‑perfect dose accuracy without a separate scale.
Think of the grinder as the gatekeeper to the coffee’s personality. A well‑tuned grind unlocks the bean’s full aromatic spectrum – fruity acidity, chocolatey body, floral notes – whereas a poorly set grind leaves you with a muted, one‑dimensional cup. Investing in a quality burr grinder, maintaining it regularly and training your baristas (or yourself) to respect the science of particle size will pay immediate dividends: quicker service, happier guests and a reputation for coffee that truly stands out.
Quick Action Checklist
Run a side‑by‑side taste test – Brew two espressos back‑to‑back: one with your current grind, one with the grind adjusted 0.2 mm coarser. Note the differences in sweetness, body and finish.
Consider an upgrade from a blade grinder – If you’re still using a blade‑type unit, look for a conical or flat‑burr grinder that offers:
Micrometre‑level adjustment so you can dial in the exact grind size for each brew method.
Low‑heat grinding to preserve the delicate aromatics in the beans.
Minimal grind retention, allowing you to purge stale grounds between batches.Easy‑to‑clean burrs and a removable hopper for quick maintenance.
Talk to your current equipment suppliers about the burr‑grinder models they stock, or ask for a “commercial‑grade burr grinder” that matches the volume and workflow of your venue. Most reputable suppliers can provide a range of options, from compact tabletop units for smaller cafés to larger floor‑standing machines for high‑throughput environments.
Document your settings – Keep a simple log of grind size, dose and brew parameters for each bean. Over time you’ll build a library of profiles that make repeatability effortless.
Remember, the perfect cup begins long before the water meets the grounds – right at the moment the beans encounter the burrs. Happy grinding!