How to Brew Green (Unroasted) Coffee: Ratio, Grind and Method

Let's clear something up first: this guide isn't really about how to brew green coffee straight from the raw seed — a green bean won't taste like coffee no matter what you do to it in water, because nothing's been roasted yet. What this is actually about is what comes next, once you've roasted your own beans at home: getting the ratio, grind, and method right so that roast doesn't go to waste.

How to Brew Green Coffee, Really: Roast First, Then Brew

If you've bought green beans and roasted a batch yourself, the brewing part isn't fundamentally different from brewing any other coffee — but a few things are worth paying attention to that don't come up with a bag off a shelf. You control the roast level, which means you also control how fast the coffee degasses, how it grinds, and how forgiving it is of small mistakes in your method. Getting good results from home-roasted beans is less about a secret technique and more about being deliberate with a few basics.

Give It a Rest Before You Brew

Freshly roasted coffee isn't ready to brew right away. For a day or two after roasting, beans are still releasing carbon dioxide, and brewing too soon usually means excess bloom, uneven extraction, and a cup that tastes flatter than it should. Let the beans sit in a container that can vent a little, then start brewing once that initial burst of gas has settled down. This single step trips up more first-time home roasters than grind size or ratio ever does.

Pick Your Grind Size

Grind size is the biggest lever you have once the beans are rested, and it needs to match your method:

• Coarse, like sea salt, for a french press — anything finer and you'll get sediment and over-extraction
• Medium, like table salt, for drip machines and most pour over coffee setups
• Extra-coarse for cold brew, where the long steep time needs a slower extraction to avoid bitterness
• Fine, closer to sugar, for espresso — though that's a separate learning curve on its own

If you don't have a burr grinder yet, it's worth prioritizing over almost any other piece of equipment. Blade grinders chop unevenly, and an uneven grind means some particles over-extract while others under-extract in the same cup, no matter how careful you are with everything else.

Get the Ratio Right

Coffee-to-water ratio is where a lot of home brewing goes wrong before it even starts — too little coffee and the cup tastes thin and sour, too much and it turns bitter and heavy. Rather than guess, weigh your coffee and your water and work from a consistent starting ratio, then adjust up or down from there based on how you actually like it. We've laid out a full breakdown on our ratio chart if you want exact numbers to start from instead of trial and error.

Weigh It Instead of Scooping

A kitchen scale is worth the small investment too — measuring by weight instead of scoops removes one more variable, especially with home-roasted beans, where density can shift slightly from batch to batch depending on roast level. Once you land on a ratio that works for a given origin, write it down somewhere you'll actually find it again. It saves you from re-solving the same puzzle every time you open a fresh jar.

Don't Ignore the Water

Water is easy to overlook, but it makes up most of what's actually in your cup. If your tap water has a strong taste of its own, filtered water will let a home-roasted origin come through more clearly — chlorine and heavy minerals tend to flatten the more delicate notes. Temperature matters too: water straight off a rolling boil will scald a finer grind and pull out extra bitterness, so give it a short moment off the heat before you pour, particularly with pour-over-style brewing where the water sits directly on the grounds.

Choosing a Method: French Press, Pour-Over, or Cold Brew

None of these methods is objectively better — they just suit different mornings and different roasts.

A french press is the most forgiving place to start with home-roasted beans: full immersion, a coarse grind, and a few minutes of patience. A pour-over rig gives you more control over the pour and a cleaner cup, but it leans on good technique and fresh coffee filters to keep sediment out. Whether you land on a slow, hands-on brew over coffee ritual each morning or something quicker on a weekday, the grind and rest time matter more than the equipment you're using.

Cold brew is its own category entirely — a long, low-temperature steep that pulls out a mellower, less acidic cup, and it's forgiving of a slightly inconsistent grind because the extraction happens so slowly. It's a good use for a roast that came out a touch darker than you meant it to.

Troubleshooting a Sour or Bitter Cup

If a cup comes out wrong, the fix is usually simpler than it feels:

• Sour or thin flavour usually means the grind is too coarse, the water too cool, or the beans didn't rest long enough after roasting
• Bitter or harsh flavour usually means the grind is too fine, the water too hot, or the brew ran long
• Flat, muted flavour often points to beans past their best — home-roasted coffee kept in a jar or canister will fade faster than a bag with a proper one-way valve, so smaller, more frequent batches tend to taste better than one big one

Keeping a quick note of the grind size, ratio, and rest time you used for each batch makes it far easier to repeat a cup you liked, or fix one you didn't. After a handful of tries, you'll have a rough formula for your favourite origin, and dialling in the next one gets faster every time.

Making It a Habit

None of this needs to be precise every single time. Once brewing becomes part of your daily grind, ratio and grind size stop being guesswork and start being muscle memory — you'll know by feel when a batch needs a finer grind or a longer rest. That's the real payoff of roasting green beans yourself: every cup is a small experiment, and eventually you get your own version of a brewed awakening dialled in exactly how you want it.

Ready to roast your own and put this to work? Our green coffee selection is the place to start, and the coffee collection is there too if you want a finished roast while you're getting your home setup sorted.