Reading about extraction does not teach you what under-extraction tastes like. Brewing the same coffee three ways and tasting the cups side by side does, in about twenty minutes.
These are the exercises from both Academy programmes, collected as a lab manual. Each is a protocol for you to run on your own equipment. CoffeeHQ has not run them and reports no results: what you find in your kitchen, with your coffee and your water, is the result.
The method they all share
Change one thing. If two things differ between cups, you cannot say which one you are tasting.
Hold the rest, and write down what you could not hold. Perfect control is not possible at home. Knowing what slipped is.
Taste side by side. The memory of yesterday's cup is not a comparison. Two cups in front of you are.
Taste at the same temperature. A hotter cup tastes different from a cooler one whatever is in it.
Hide the labels where you can. Mark the undersides and shuffle. What you expect changes what you perceive.
Write before you decide. Note what you observe, then work out what it means.
Every exercise ends with what it cannot show. A comparison on one coffee, on one day, by one taster is an illustration and not a proof, and a result of “I could not tell them apart” is as useful as any other. The Tasting Lab worksheet is a convenient place to record what you taste.
Brewing variables
One variable at a time: ratio, grind, temperature, water and method, each isolated as far as a kitchen allows.
The ratio ladder
Objective. Taste what the brew ratio does on its own, so that 'stronger' and 'more extracted' stop meaning the same thing.
You will need
One coffee, enough for three small brews
A scale reading to 1 g or better
Your usual brewer and three matching cups
Keep the same
Same coffee, same grind setting, same water and water temperature
Same amount of water in each brew, so the brews take a similar time
Same pouring or steeping routine
Procedure
Choose a water amount you can brew three times, for example 240 g.
Brew at 1:15, 1:16 and 1:17 by changing only the coffee dose: 16 g, 15 g and 14 g for 240 g of water.
Label the cups underneath so you can shuffle them.
Let all three cool for a few minutes, then taste them in a shuffled order.
Rank them from heaviest to lightest before looking at the labels.
What to notice
Which cup feels heaviest in the mouth?
Does the balance of sour, sweet and bitter change, or mostly the intensity?
Could you reliably tell the neighbouring cups apart?
Reading what you found
If the main difference you find is weight and intensity, you are tasting concentration. If the smallest dose also tastes more bitter or drying, that is extraction moving too: less coffee for the same water lets each particle give up a little more. Both effects are real, and the ratio moves both, which is why a ratio change is rarely a pure strength change in a percolation brewer.
What this cannot show
A one-step ratio change is small. Not being able to tell 1:16 from 1:17 is a normal result, not a failed exercise.
Changing the dose changes the depth of the coffee bed, so brew time shifts slightly in pour-over. Note the times rather than ignoring them.
One coffee on one day. A darker or lighter roast can respond differently.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Find out what under- and over-extraction taste like on your own grinder, with your own coffee.
You will need
One coffee, a burr grinder, a scale, a timer
A pour-over or immersion brewer and three cups
Keep the same
Same dose, same water amount, same water temperature
Same pouring pattern, or the same steep time for immersion
Procedure
Brew your normal recipe and call it the baseline.
Brew again with the grinder set clearly coarser — a step you can see in the grounds.
Brew a third time set clearly finer than the baseline.
Record the total brew time for each.
Taste all three side by side once they have cooled a little.
What to notice
Which cup is sharpest or most sour? Which is most bitter or drying?
Which has the least flavour overall?
How much did brew time change between settings?
Reading what you found
The coarse brew usually leans thin and sharp and the fine one heavier, more bitter or drying. If your fine brew tastes both sour and harsh, or the bed drained unevenly, the grind may have been fine enough to cause channelling rather than simply more extraction. The useful outcome is a personal reference: you now know which direction each fault lies in on your equipment.
What this cannot show
In pour-over, a finer grind also lengthens brew time, so grind and time move together. An immersion brewer with a fixed steep separates them better.
Grinder settings are not comparable between grinders. The numbers you write down apply to yours only.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Two temperatures, one coffee
Objective. Judge how much water temperature matters for the coffee you actually drink.
You will need
One coffee, a kettle, a thermometer or variable-temperature kettle
An immersion brewer or cupping bowls, a scale, a timer
Keep the same
Same dose, grind, water amount and steep time
Preheat both brewers the same way, or neither
Procedure
Brew one cup with water just off the boil.
Brew a second with water about 10 °C cooler.
Use an immersion method with a fixed steep so that time does not change with temperature.
Taste both at the same drinking temperature — let the hotter one catch up.
What to notice
Is one cup sharper or flatter?
Is one more bitter?
Is the difference bigger or smaller than the grind difference you found in 'Grind three ways'?
Reading what you found
Hotter water generally extracts faster, so the cooler cup often tastes a little less developed. With a dark roast the cooler cup may simply taste less bitter and be the one you prefer. If you cannot tell them apart, that is informative: for this coffee and method, temperature is a fine-tuning control rather than a main one.
What this cannot show
Slurry temperature is lower than kettle temperature and falls during the brew. You are comparing starting points, not held temperatures.
Tasting one cup hotter than the other changes how it tastes regardless of how it was brewed.
Safety. Handle near-boiling water with care, and let cups cool before tasting.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Weak is not the same as under-extracted
Objective. Taste a diluted cup beside an under-extracted one, so the two words stop being interchangeable.
You will need
One coffee, an immersion brewer or cupping bowls, a scale, a timer, three cups
Keep the same
Same coffee, dose, water and temperature for every brew
Procedure
Brew a normal cup. This is the reference.
Pour half of it into a second cup and add an equal weight of hot water. This cup is weaker, with the same extraction.
Brew a third cup with the same recipe but stop the steep at about a quarter of the normal time. This cup is under-extracted.
Taste all three, coolest last.
What to notice
Which of the two 'weak' cups still tastes balanced?
Which tastes sour or hollow?
Does the diluted cup taste like a thin version of the reference?
Reading what you found
The diluted cup should taste like the reference with the volume turned down: the same balance, less of it. The short-steeped cup usually tastes different in kind — sharper and less sweet — because the compounds that dissolve quickly dominate. If you can tell these two apart, you can decide whether a cup needs more coffee or more extraction.
What this cannot show
The short steep is also somewhat weaker, so the third cup differs in both respects. The diluted cup is the one that isolates strength.
Without a refractometer these are qualitative judgements.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Find out whether your water is a limiting factor before spending anything on it.
You will need
One coffee, your tap water, and one or two alternatives: filter-jug water and a low-mineral bottled water
Cupping bowls or an immersion brewer, a scale
The mineral analysis from each bottle label, and your water supplier's report for the tap
Keep the same
Same dose, grind, water amount, temperature and steep time
Heat each water in a clean kettle, rinsed between waters
Procedure
Write down the hardness and alkalinity (or bicarbonate) of each water where you can find it.
Brew the same recipe with each water.
Taste side by side, shuffled, at the same temperature.
Taste the plain waters too.
What to notice
Does one cup taste flatter or chalkier? Sharper or thinner?
Does the water with the highest bicarbonate make the most muted cup?
Does any water taste of something on its own?
Reading what you found
High alkalinity tends to mute acidity and can make a lively coffee taste flat; very soft, low-mineral water tends to taste sharper and thinner. If your tap water makes a cup you like as much as the others, water is not your problem. If the differences are large, the water-suitability tool can help you decide what to change.
What this cannot show
Bottled waters differ in several minerals at once, so you cannot attribute a difference to one of them.
Never use distilled or pure reverse-osmosis water in an espresso machine without checking the manufacturer's guidance.
Supplier reports are averages for an area and season.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Taste what a brewing method contributes, with the coffee held constant.
You will need
One coffee and two brewers that differ in filter or contact style — for example a paper pour-over and a French press
A scale, a timer, two matching cups
Keep the same
Same coffee, same water, same ratio in both brewers
Grind set appropriately for each method — this is the one thing that has to differ
Taste at the same temperature
Procedure
Brew both as close together in time as you can manage.
Before tasting, look at each cup against a white surface.
Taste side by side and describe body, clarity and what is left in the mouth afterwards.
Compare what you found with the brewing method comparator's description of the same pair.
What to notice
Which cup is cloudier? Is there sediment at the bottom of either?
Which feels heavier?
In which cup is it easier to pick out separate flavours?
Reading what you found
Differences in texture, cloudiness and sediment are mostly the filter. Differences in sharpness or bitterness may be the method, or may be that the two brews did not extract equally — which is likely, because you chose both grind settings yourself.
What this cannot show
You cannot hold extraction equal across two methods without measuring it, so this compares two recipes as much as two methods.
The comparator describes tendencies for a competent recipe on each method. Your cups can disagree with it for good reasons.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
The old way and the filtered way
Objective. Taste the difference between coffee's oldest preparation and its most common modern one.
You will need
One coffee, ground fine for the pot and medium for the filter
A small saucepan or a cezve, a paper-filter brewer, two cups
Keep the same
Same coffee and the same ratio by weight
No sugar or spice in either, for this comparison
Procedure
In the pot, combine finely ground coffee and cold water and heat gently until the foam rises, then take it off the heat. Do not let it boil hard.
Let it stand for a minute so the grounds settle, and pour carefully.
Brew the same coffee through paper.
Taste side by side, leaving the last of the unfiltered cup in the bottom.
What to notice
How do body and texture differ?
Which carries more aroma? Which is clearer?
What is left at the bottom of each cup?
Reading what you found
For most of coffee's history the grounds stayed in the pot, and in a large part of the world they still do. Tasting the two together makes later history concrete: paper filtration was a twentieth-century change to how coffee feels in the mouth, not only a convenience.
What this cannot show
A saucepan is not a cezve, and neither reproduces a tradition. Preparation, serving and the social setting are part of those drinks; see the preparation atlas.
Unfiltered coffee contains more of the coffee oils that paper removes. The coffee and health page covers what is known about them.
Safety. Coffee heated in a pot can foam over suddenly. Use low heat and do not leave it.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
What a shot is made of, how to dial one in methodically, and one contested idea to test.
One shot in three cups
Objective. Taste how an espresso changes from its first drops to its last.
You will need
An espresso machine and grinder, dialled in to a shot you like
Three small cups and a scale
Keep the same
Your normal dose, grind and total yield
A single uninterrupted shot
Procedure
Start the shot into the first cup.
At roughly one third of your usual yield, slide the second cup under the spouts; at two thirds, the third.
Stop at your usual total yield.
Taste each cup on its own, then pour all three together and taste the whole.
What to notice
Which third is thickest and most intense? Which is thinnest?
Where does sourness sit? Where does bitterness arrive?
Does the combined cup taste better than any single part?
Reading what you found
The early part of a shot is usually the most concentrated and sharpest, and the last part the thinnest and most bitter. That is why stopping a shot earlier or later changes its balance and not only its strength, and why yield is a flavour control.
What this cannot show
Swapping cups by hand is imprecise. The exercise shows a direction, not a measurement.
A different coffee, roast or ratio will divide differently.
Safety. Keep fingers clear of the group and the hot portafilter while moving cups.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Dial in an espresso by changing only the grind, and keep a record that proves it.
You will need
Espresso machine, grinder, scale that fits under the cup, timer
A notebook or the copy button on the dial-in assistant
Keep the same
Fixed dose and fixed target yield — choose them first and do not touch them
The same puck preparation every time
Procedure
Choose a dose that suits your basket and a target yield of about twice the dose.
Pull a shot. Record dose, yield, time and three words for the taste.
Change the grind by a small step in the direction the taste and the time suggest.
Purge a little coffee through the grinder, then pull again and record the same four things.
Stop when a shot tastes balanced, or after five shots, whichever comes first.
What to notice
How much did the time move per grind step?
Did the taste change in the direction you predicted?
Was there a shot where time looked right and the taste did not?
Reading what you found
If each step moved the shot the way you expected, you have found how your grinder's steps map to your machine. If a shot with a sensible time still tasted sour and harsh together, suspect uneven extraction rather than grind, and look at puck preparation before going further.
What this cannot show
Five shots use real coffee. The point is the method, so a cheaper bag is a reasonable choice.
The setting you find applies to this coffee at this age. Expect to adjust again within days.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Test for yourself whether a coarser, faster, higher-ratio shot can match a traditional one.
You will need
Espresso machine, grinder with fine adjustment, scale, timer
A coffee you have already dialled in conventionally
Keep the same
Same coffee, same dose, same puck preparation
Same water and machine temperature
Procedure
Pull your dialled-in shot and record dose, yield, time and taste.
Grind noticeably coarser and pull a shot to a higher yield — around 1:2.5 to 1:3 — that finishes in roughly half the time.
Taste both side by side, the conventional shot first and then in the other order.
If you own a refractometer, measure both and compare extraction yield.
What to notice
Which is heavier? Which is clearer?
Is the faster shot sour, or simply lighter?
Was the flow from the basket more or less even?
Reading what you found
A fast, coarse shot is thinner by construction, because the ratio is longer. Whether it is also well extracted depends on the coffee, the basket and the grinder; some published work reports that coarser grinds and shorter shots can extract more evenly, and some coffees simply taste empty this way. Your two cups are the evidence that applies to your setup.
What this cannot show
Without a refractometer you are judging extraction by taste, which is confounded by the difference in strength.
Results depend heavily on grinder and basket. This does not generalise.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Milk temperature, drink proportions, sequence, pouring control and machine care.
Milk at three temperatures
Objective. Learn what milk tastes and feels like at, below and above the usual serving range.
You will need
Fresh cold milk of one type, a milk jug, a milk thermometer
A steam wand, or a saucepan and a handheld frother
Three small cups
Keep the same
Same milk, from the same carton
Same amount in the jug each time
Procedure
Heat one portion to about 50 °C, one to about 60 °C and one to about 70 °C, measuring with the thermometer.
Pour each into its cup and taste the plain milk as soon as it is cool enough to drink comfortably.
Look at the foam on each after one minute.
What to notice
Which tastes sweetest?
Does the hottest one taste cooked or flatter?
Which foam is glossiest, and which has gone dry or coarse?
Reading what you found
Most people find milk in the middle of this range sweetest and most pleasant, and milk heated well past it noticeably cooked, with foam that turns stiff and dull. Where your own preference sits is the answer that matters: it sets the temperature you should aim for when steaming for yourself.
What this cannot show
Perceived sweetness changes with the temperature at which you taste, not only the temperature the milk reached.
Plant milks behave differently and some split when overheated; repeat the exercise separately for each milk you use.
Safety. Steam and hot milk scald. Never taste straight from the jug, and purge and wipe the wand after each use.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Taste how the amount of milk and the depth of foam change a drink built on the same coffee.
You will need
Espresso machine with a steam wand, milk jug, scale
Three cups of different sizes: roughly 120 ml, 160 ml and 250 ml
Keep the same
The same espresso recipe for all three
The same milk, steamed to the same temperature
Procedure
Pull the same shot three times, or split two doubles as your equipment allows.
Build a small drink with about as much milk as espresso, a medium one with a thin foam layer, and a large one with more milk.
Weigh the milk that goes into each cup and write it down.
Taste them in order of size, then in reverse.
What to notice
In which drink is the coffee clearest?
Where does the milk's sweetness take over?
Does foam depth change how strong the first sip seems?
Reading what you found
The espresso was the same, so what you taste changing is dilution and texture. This is the practical meaning of the names on a café menu: a cortado, a flat white and a latte are mostly different answers to how much milk a shot should carry.
What this cannot show
Café recipes vary by country and by shop. The sizes here are illustrations, not definitions.
Three milk drinks is a lot of milk and caffeine; share them.
Safety. Steam scalds. Purge and wipe the wand after every jug.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Find a working order that gets two milk drinks to the table hot and at the same time.
You will need
Espresso machine with steam wand, grinder, two cups, one jug large enough for both drinks
A timer, and something to write on
Keep the same
The same two drinks each attempt
The same starting state: clean, warm, tidy
Procedure
Write down the order you think is best before you start.
Make the two drinks and time from picking up the portafilter to setting down the second cup.
Note every moment you waited with idle hands, and every moment something sat going cold.
Rewrite the order to remove one wait, and run it again.
Check the quality of both attempts: was the second shot as good as the first, and was the milk still glossy when poured?
What to notice
Where did time go that you did not expect?
Did the faster run cost anything in the cup?
Which tasks could overlap — for example steaming while the shot runs, if your machine can do both?
Reading what you found
Most lost time in a home workflow is waiting and searching, not working. If the faster sequence produced worse drinks, the sequence is wrong, not too fast: speed that costs quality is the thing a workflow is meant to avoid.
What this cannot show
A single-boiler machine cannot brew and steam together, which changes the best order entirely.
Two runs show a direction. Consistency comes from repeating the same order every day.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Build control of height, flow and position before latte art has milk and coffee riding on it.
You will need
A milk jug, a wide cup, cold water
Optionally one small drop of washing-up liquid if you want to practise aerating with a steam wand — never for drinking
Keep the same
The same jug and cup you use for real drinks
The same fill level each time
Procedure
Fill the jug to your usual level with water.
Hold the cup tilted and pour from a height in a thin stream, moving in small circles, until it is half full.
Lower the jug until the spout almost touches the surface, and increase the flow.
Practise holding the stream in the centre while levelling the cup, then finishing with a lift and a straight line through.
Repeat until the three phases — high and thin, low and fast, lift and cut — feel like one movement.
What to notice
Can you change flow rate without changing height, and height without changing flow?
Does the stream wander when you level the cup?
Is your jug hand or your cup hand doing more of the work?
Reading what you found
Water shows you the mechanics and nothing about texture. If the movement is steady with water and the pattern still fails with milk, the milk is the problem, and the place to work is steaming rather than pouring.
What this cannot show
Water does not float on espresso the way microfoam does, so no pattern will form. This trains control only.
Text and practice with water cannot replace watching your own pour, on video or with someone experienced beside you.
Safety. Water with detergent in it is for the sink. Rinse the jug and wand thoroughly afterwards.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Turn 'I should clean it more' into a schedule that matches your machine and your water.
You will need
Your machine's manual
A torch, a clean cloth, a group brush if your machine has a group head
Your water hardness, from a test strip or your supplier's report
Keep the same
Machine switched off and cool for any inspection inside the group or drip tray
Procedure
Read the manual's cleaning and descaling section and note what it requires and what it forbids.
Check whether your machine has a three-way valve, which decides whether backflushing applies at all.
Inspect the shower screen, the group gasket, the steam tip holes, the drip tray and the grinder chute, and write down what you find.
Enter your machine type, water hardness and usage into the maintenance planner.
Compare its schedule with what you actually do, and write the three biggest gaps on a note kept by the machine.
What to notice
Is there old coffee oil on the screen or in the basket?
Are any steam tip holes partly blocked?
When was the machine last descaled, and with what water?
Reading what you found
Oily residue means daily or weekly cleaning is being skipped. Scale risk depends on your water, so a soft-water home and a hard-water home need very different descaling intervals. The manual outranks any general schedule, including CoffeeHQ's.
What this cannot show
A visual check cannot see scale inside a boiler.
This is an audit, not a service. Anything involving opened panels, electrics or pressurised parts belongs to the manufacturer's instructions or a technician.
Safety. Never open or dismantle a hot or pressurised machine. Use only cleaning products the manufacturer permits, and rinse as instructed.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Describing what you taste, separating the basic sensations, and controlling for expectation.
Your first side-by-side
Objective. Show yourself that coffees differ in ways you can already describe.
You will need
Any two different coffees — two bags, or one bag and what you normally drink
Two matching cups and your usual way of brewing
Keep the same
Same recipe for both
Tasted at the same temperature, without milk or sugar
Procedure
Brew both and set them side by side.
Smell each before tasting.
Taste one, then the other, then the first again.
Write three plain words for each cup. Ordinary words are fine: sharp, heavy, sweet, burnt, thin.
Write one sentence on how they differ.
What to notice
Which is heavier? Which is sharper?
Which taste lasts longer after you swallow?
Is the difference bigger in the smell or in the taste?
Reading what you found
If you could write a sentence about the difference, you can taste coffee. Specialist vocabulary is a way of being more precise about differences you already perceive; it is not a different sense.
What this cannot show
With two coffees you cannot say why they differ — origin, roast, age and processing are all tangled together. Later levels separate them.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Learn to tell sour from bitter from astringent, which most people confuse in coffee.
You will need
Four glasses of water
A pinch of sugar, a few drops of lemon juice, a pinch of salt, and strongly over-steeped black tea
A cup of brewed coffee
Keep the same
Make each solution weak — just strong enough to recognise
Rinse with plain water between tastes
Procedure
Make four glasses: sugar in water, lemon in water, salt in water, and the over-steeped tea.
Taste each and note where and how you feel it, and how long it lasts.
In the tea, separate the bitter taste from the drying, rough feeling on the tongue and cheeks.
Now taste the coffee and name which of those sensations are present.
Add a few drops of the lemon solution to a little coffee, and a few grains of sugar to another, and taste the change.
What to notice
Is sourness quick and sharp for you, and bitterness slower and at the back?
Can you feel astringency as a texture rather than a taste?
Which sensation did you previously call 'bitter' that was actually sour or drying?
Reading what you found
Sour, bitter and astringent are three different things: two tastes and one tactile sensation. Under-extracted coffee is typically described as sour and over-extracted coffee as bitter and astringent, so being able to tell them apart is the basis of every troubleshooting decision in brewing.
What this cannot show
Kitchen solutions are uncontrolled; sensory training kits use measured concentrations.
People differ in sensitivity to bitterness for genetic reasons, so your threshold is not anyone else's.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. See how much of what you taste comes from what you have been told.
You will need
Two coffees you can tell apart by their bags — different origin, roast or price
Four identical cups, a helper or a way to shuffle cups you cannot see through
Keep the same
Same recipe and water for both
Same cup temperature when tasting
Procedure
Brew both coffees. Taste them knowing which is which and write three words for each, plus which you prefer.
Have someone pour them again into unmarked cups, or mark the undersides and shuffle.
Taste blind. Write three words for each and your preference again.
Reveal the cups and compare the two sets of notes.
What to notice
Did your preference change?
Did words from the bag label appear in your labelled notes but not your blind notes?
Could you say which cup was which?
Reading what you found
Notes that survive blind are the ones you actually perceived. Notes that vanish were supplied by expectation. Neither outcome is embarrassing — expectation effects are well documented in sensory research and are the reason professional tasting is done blind.
What this cannot show
Two coffees and one taster is an illustration, not a test. Preference can flip for many reasons, including which cup you tasted first.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
A first triangle test
Objective. Find out whether a difference you believe in is one you can actually detect, using the simplest formal method in sensory analysis.
You will need
Two brews that differ in one way — two grind settings, two waters, two coffees
Three identical cups per round, a helper to pour
Keep the same
Same volume and temperature in every cup
Cups identical and unmarked on top
Procedure
Your helper fills two cups with one brew and one cup with the other, in an order you do not see.
Taste all three and pick the odd one out. You must choose, even if you are guessing.
Repeat for at least six rounds, with the helper varying which brew is the odd one and where it sits.
Count how many times you were right.
What to notice
How confident did you feel in each round, and did confidence match accuracy?
Did the cups get harder or easier to separate as they cooled?
Reading what you found
Guessing alone picks the odd cup one time in three. Getting two out of six proves nothing; getting five or six out of six is hard to do by luck. Sensory laboratories use the same logic with many more tasters and statistical tables to decide whether a difference is detectable.
What this cannot show
A triangle test tells you whether a difference is detectable, not which cup is better or how big the difference is.
Six rounds by one person is a small sample. Treat a middling score as 'not shown' rather than 'no difference'.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Species, origin, processing and roast, compared in the cup with the limits of each comparison stated.
Sorting a handful of beans
Objective. See, in roasted coffee, evidence of what happened to the fruit on the tree.
You will need
About 50 g of whole roasted beans, a white plate, good light
Optionally a second, cheaper coffee to compare
Keep the same
Sort the same weight of each coffee if comparing two
Procedure
Spread the beans in a single layer.
Pick out any that are clearly paler than the rest, any that are broken, and any shell-shaped or hollow pieces.
Count each group.
Look at a normal bean: find the centre cut and any papery chaff left in it.
If you have enough pale beans, crush one and smell it beside a normal bean.
What to notice
How uniform are size and colour?
How many pale beans are there in the sample?
Do the pale beans smell different?
Reading what you found
Pale beans that did not brown with the rest are usually called quakers and are generally attributed to unripe fruit, which lacks the sugars that brown during roasting. Their number tells you something about how selectively the cherries were picked and sorted. Uniform size points to screening at the mill. None of this tells you how the coffee tastes — only how carefully it was handled.
What this cannot show
Roasted beans show only some defects. Formal grading is done on green coffee, against a written defect standard.
A light roast makes pale beans harder to spot; a dark roast hides them almost entirely.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Taste the difference between the two species that make up almost all the coffee in the world.
You will need
One coffee labelled 100% arabica and one that is 100% robusta, or a blend that states its robusta share
Cupping bowls or your usual brewer, two cups
Keep the same
Same recipe and water
As similar a roast level as you can find — this is the hard part
Procedure
Look at the beans first: shape, size and the line of the centre cut.
Brew both the same way.
Smell, then taste, side by side.
Describe body, bitterness and acidity for each.
What to notice
Which is more bitter? Which has more acidity?
Which is heavier in the mouth?
Do the beans look different?
Reading what you found
Robusta is commonly described as heavier, more bitter and lower in acidity, and it contains more caffeine, which is itself bitter. If your robusta is also roasted darker than your arabica, much of what you taste may be roast. Well-processed robusta exists and can upset the textbook description, which is worth knowing first-hand.
What this cannot show
Two bags cannot separate species from roast, processing and quality grade.
Pure robusta can be hard to buy at retail; a stated blend is an acceptable substitute but weakens the comparison.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Find out how far origin descriptions hold up in your own cup.
You will need
Three coffees from three countries, ideally the same roaster and a similar roast level
Three bowls or cups, a scale, a way to shuffle them
Keep the same
Same recipe, same water
Tasted blind after an initial labelled look
Procedure
Before tasting, write down what you expect from each, using the bag and the CoffeeHQ origin page.
Brew all three and taste them blind.
Write notes for each cup and guess which is which.
Reveal them, and compare your notes with your expectations.
What to notice
Which expectation held, and which did not?
Did you identify any cup correctly?
Was the biggest difference between cups one of acidity, body or flavour?
Reading what you found
Origin tendencies are real at the level of large averages and unreliable for any single bag, because variety, processing, altitude and roast vary within every country. A mismatch between the description and your cup is the normal case, and is the reason CoffeeHQ's origin pages describe tendencies rather than promises.
What this cannot show
Three bags is a tiny sample of three countries.
If the coffees differ in processing, you may be tasting process rather than place.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Taste what processing can do, with as much else held constant as retail coffee allows.
You will need
A washed and a natural coffee, ideally from the same country and roaster, at a similar roast
Two bowls or cups
Keep the same
Same recipe, same water
Tasted blind if possible
Procedure
Smell the dry grounds of each.
Brew both and taste side by side.
Describe fruit character, body and how clean the finish is.
Decide which you would call 'cleaner' and which 'fruitier', then check the bags.
What to notice
Is one noticeably fruitier or more wine-like?
Is one heavier?
Which finish is shorter and clearer?
Reading what you found
Naturals are often described as fruitier and heavier and washed coffees as cleaner and brighter, because the fruit stays on the seed during drying in one and is removed first in the other. Many pairs will fit that description and some will not: a carefully dried natural can be very clean, and a washed coffee with a long fermentation can be very fruity.
What this cannot show
Two coffees from the same country are still different lots, often different varieties and farms.
This shows what processing can do, not what it always does.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Separate what roasting adds from what the coffee brought with it.
You will need
A light and a dark roast, ideally of the same coffee from one roaster; otherwise from the same country
A white plate, two cups, a scale
Keep the same
Same recipe by weight
Same water
Procedure
Compare the beans: colour, surface oil, size.
Weigh out the same dose of each and notice the difference in volume.
Brew both the same way and taste side by side.
Describe acidity, bitterness, body and which flavours you would attribute to the roast itself.
What to notice
Which beans are larger and which are oily?
Which cup is more acidic and which more bitter?
Which cup tastes more of 'roast' and which more of fruit or flowers?
Reading what you found
Darker roasts are usually less acidic, more bitter and heavier, with flavours that come from the roasting itself; lighter roasts usually keep more of what distinguishes one coffee from another. Dark beans are also less dense, which is why a scoop of dark roast weighs less than a scoop of light — and why this course weighs everything.
What this cannot show
The same recipe does not suit both roasts equally, so one cup may simply be brewed less well.
If the two roasts are different coffees, origin is mixed into the comparison.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
No coffee needed: what a bag tells you, what a certification requires, and how well a claim is supported.
Reading a bag as a buyer would
Objective. Work out what a coffee label actually tells you, and what it leaves out.
You will need
Two or three bags of coffee, or their product pages
Something to write on
Keep the same
Use the same list of questions for every bag
Procedure
For each bag, look for: country, region, farm or washing station or cooperative, variety, altitude, processing method, harvest or crop year, roast date.
Mark each item as stated, vague or absent.
Note any grade term — AA, Supremo, SHB, Grade 1 — and look up which country's system it belongs to.
Note any claim with no definition behind it, such as 'premium' or 'gourmet'.
What to notice
Which bag could you trace furthest back towards a farm?
Which grade terms describe size, which altitude, and which defects?
Is there a roast date, or only a best-before date?
Reading what you found
Traceability is not quality, but it is the precondition for knowing anything about quality. A grade term tells you about one country's sorting rules, most often bean size, and is not comparable across countries. A missing roast date tells you the seller does not expect you to ask.
What this cannot show
A label is a claim. This exercise checks what is claimed, not whether it is true.
Small producers are sometimes unnamed for commercial reasons rather than because the coffee is untraceable.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Replace a general impression of a certification with what its published standard says.
You will need
A bag of coffee carrying a certification mark, or a product page that names one
Internet access
Keep the same
Read the certifier's own published standard, not a summary by a seller
Procedure
Write down what you assume the mark guarantees.
Find the certifier's current standard for coffee.
Look for three things: whether it sets a minimum price, what it requires on labour and environment, and how compliance is audited.
Compare what you found with what you assumed.
Read CoffeeHQ's certifications guide and note anything it adds or that you would correct.
What to notice
Does the standard guarantee a price, a premium, a practice, or an audit?
Does it apply to the farm, the cooperative, or the supply chain?
Does it say anything at all about how the coffee tastes?
Reading what you found
Certifications certify different things, and none certifies cup quality. A coffee without a logo is not thereby worse on any of those dimensions — certification costs money, and many small producers sell on direct relationships instead. The useful habit is to ask what, exactly, is being claimed and who checked.
What this cannot show
Standards are revised. What you read is the current version, not the one in force when the coffee was grown.
A standard describes requirements, not outcomes on a particular farm.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.
Objective. Practise deciding how much a confident claim is worth before acting on it.
You will need
One claim you have recently read or heard — about a gadget, a technique or a health effect
Something to write on
Keep the same
Use the same five questions every time
Procedure
Write the claim as one sentence that could be true or false.
Ask who is making it and whether they sell something that depends on it.
Ask what kind of evidence is offered: a measurement, a blind comparison, one person's taste, or none.
Ask whether the comparison held everything else constant.
Ask how you could test it yourself with a triangle test, and whether the result would change what you do.
Place the claim on the ladder in this level: measured, sourced description, common tendency, reasoned explanation, or one person's note.
What to notice
Did rewriting the claim as one sentence change how strong it sounded?
Is the evidence a measurement of the thing claimed, or of something nearby?
Would a positive result matter in your kitchen?
Reading what you found
Most coffee advice is reasoned explanation or one person's note, and plenty of it is still useful. The point is not to dismiss it but to hold it with the right amount of confidence — and to notice that the same test applies to everything CoffeeHQ publishes.
What this cannot show
An audit tells you how well supported a claim is, not whether it is true. Weakly supported claims are sometimes right.
A protocol for you to run. CoffeeHQ has not run it and reports no result from it.