Working a coffee bar: a day, decision by decision

The station, as the work moves through it

CoffeeHQ explanation

A model of one drink's path across a typical espresso station. Bars arrange it differently; the point is that every stage hands something to the next, and a delay or a mess at one stage is felt at the others.

Opening: what is checked before the first customer

CoffeeHQ explanation

An espresso machine takes time to come to a steady temperature, and how long is a property of the machine: a large commercial machine left on a timer overnight and a small one switched on at the door are different problems. The opening check that every bar shares is simpler. Is the machine at working temperature, is there water and is it the water the machine expects, are the grinders loaded with the right coffee, and are the fridges cold.

The fridge is the one item on that list with a rule behind it, covered below. The rest is practice, and the useful habit is writing down what was found. A bar that records which coffee went into which grinder and where the grind ended up yesterday starts today's dialling-in from information and not from memory.

The opening checks, in the order they depend on each other

CoffeeHQ explanation

Practice, set out as an order. None of it is a standard and a bar will add items of its own; the order matters because each check leans on the one before.

1. Station readiness. Everything the first drink needs is in its place before the first drink is ordered: clean cloths with separate jobs, the knock box empty, the scale working, cups and jugs clean and where a hand reaches for them. A missing cloth found during a queue costs more than one found now.
2. Machine warm-up. The machine is at working temperature by its own indicator or, where it has none, after the time its manual gives. Baristas leave the portafilter locked in so that it warms with the group, and run water through the group to see that it arrives and runs clear. How long any of this takes belongs to the machine and its manual; no time is given here.
3. Grinder setup. Each grinder holds the coffee it is meant to hold, with enough in the hopper for the opening period, and its setting is where yesterday's note says it ended. The first grounds out after a night are yesterday's coffee, left in the burrs and the chute, and bars commonly grind a little through and discard it before the first shot. How much a grinder holds back differs from one grinder to another.
4. Recipe verification. One shot is pulled to the written recipe, with the dose weighed, the yield weighed and the time noted, and it is tasted before anything is served. The recipe is a starting point for today and not a target: if the shot tastes right at a different time from yesterday's, the taste decides. Whatever is changed is written where the next person will see it.
5. Milk and storage. The fridge is at the temperature the business's own procedures require, checked with a thermometer and recorded if those procedures say so. Milk and plant drinks are in date, opened cartons are marked as the business requires, and coffee is kept closed and away from heat. The temperature rule itself is set out in the section on milk below, and it is the regulator's, not this page's.

A home machine has the same five checks in miniature.

Dialling in, and why it is done again during the day

CoffeeHQ explanation

Dialling in means adjusting the grind, and sometimes the dose or the yield, until the espresso tastes the way the bar wants it to. It is done by taste. A recipe gives a starting point, usually a dose, a yield and a rough time, and the shot is judged in the cup, changed one thing at a time and tasted again.

It does not stay done. Coffee changes as it ages after roasting, and bars commonly find that the grind needs moving as the day warms up or the hopper runs low. No study measuring that drift in a working café was read for this page, so treat it as what baristas report and not as an established effect. What follows from it in practice is a habit: taste a shot at intervals, not only when a customer complains.

One finding from the research is worth carrying behind the bar. In a study that pulled espresso across a range of grind settings, extraction did not keep rising as the grind got finer; past a point it fell, which the authors read as water finding uneven paths through a bed that had become too tight. A shot that tastes worse after going finer is not necessarily a mistake at the grinder.

Through the shift: drift, a change of coffee, and the grinder

CoffeeHQ explanation

A recipe set at opening is a record of what worked at opening. Through a shift the things it depended on move: a new bag may be a different age from the last, the hopper empties, the room and the grinder warm up. Baristas commonly report that shots speed up or slow down over a session and that the grind has to be moved to follow. As the section above says, no study measuring that in a working café was read for this page, so a bar's own record is the evidence it has. A sheet with the time of day, the dose, the yield, the shot time and one line of taste at each check is enough to show whether anything moved, and roughly when.

One study bears on one part of this, and it is worth saying exactly what it is. Researchers ground a single coffee at four bean temperatures, from room temperature down to that of liquid nitrogen, and measured the particles. Colder beans gave a narrower spread of sizes and a finer most-common size. They brewed and tasted nothing. So the study supports the statement that beans at a different temperature grind differently at one setting, which is a reason to check a setting when coffee comes from somewhere colder or warmer than the last lot did. It does not show that a warm afternoon changes a shot, how large any such change would be, or what it would do to taste. Nothing was read on humidity.

A change of coffee is a new dial-in, not an adjustment. A different coffee, or the same coffee from a different roast date, starts from the recipe's starting point and is tasted before it is served. The grinder is purged first, because what it holds is the previous coffee; how much it holds differs between grinders. If two coffees share a grinder across a day, the setting each ended on is written down.

Adjustments follow the same rule as dialling in: one change, then a taste. Move the grind when the balance of the cup has moved, the yield when its strength has, and neither when the only thing that moved is the clock. Write the change where the next person will see it, with the time. A recipe that three people have each nudged without telling the others is no longer a recipe.

Milk: the part with rules attached

Sourced

Milk is the one ingredient on a coffee bar that food-safety rules treat as needing temperature control. The details depend on where the bar is, and a business must follow its own regulator. Two published texts show what such rules look like. Neither mentions coffee bars, steamed milk or steam wands; how they apply to one is for the business and its regulator, and nothing here is compliance advice.

The United States model Food Code, the 2022 edition, defines food that needs time and temperature control to include animal food that is raw or heat-treated, and elsewhere lists milk among animal foods. It requires such food to be held at 5 °C (41 °F) or below, or at 57 °C (135 °F) or above, except while it is being prepared, cooked or cooled.

The same code allows time alone to be the control for a working supply, on conditions. Written procedures must be prepared in advance, kept on the premises and shown to the regulator on request. Under the four-hour option the food must be at 5 °C or below when it leaves the fridge, be marked with the time four hours later, and be served or thrown away by then; a container that is unmarked, or marked beyond the limit, is thrown away. A six-hour option exists as well, with more attached: the food must start at 5 °C or below, must never rise above 21 °C (70 °F), must be monitored or kept in a room that guarantees that, must be marked with both the time it came out and the time six hours later, and must be thrown away if it passes 21 °C. The Food Code is a model that states adopt in their own versions, so the rule that applies is the local one.

In the United Kingdom, the Food Standards Agency's pack for caterers says that keeping chilled food at 8 °C or below is a legal requirement in England, Wales and Northern Ireland and recommended in Scotland, and recommends setting fridges at 5 °C or below to achieve it. It describes a four-hour exception for displaying food out of chilled storage, which can be used once: food out for less than four hours can go back in the fridge until it is used, and food out for longer must be thrown away. It also says to keep the time chilled food spends at room temperature during preparation as short as possible.

What this means at the bar is a choice each business makes and writes down: milk lives in the fridge and comes out a jug at a time, or a working supply sits out under a clock. Neither text says anything about milk that has already been steamed. On the code's own terms, milk sitting in a jug after steaming is neither at 5 °C or below nor at 57 °C or above, so it is food out of temperature control; whether leftover milk may be kept or steamed again is a question for the business's written procedures and its regulator, not for this page.

The same code requires equipment and utensils used with such food to be cleaned at least every four hours through the day, and lists exceptions, among them equipment kept at refrigerated temperatures and a schedule the regulator has approved. Whether a milk jug or a steam wand falls under that requirement is, again, the local regulator's reading; the code does not name either.

One wand, several milks

Sourced

A bar that steams cow's milk and plant drinks on the same wand and in the same jugs has an allergen question as well as a hygiene one. The Food Standards Agency's pack lists milk among the allergens a caterer must manage. Its instruction for a customer who has asked for food without a particular allergen is that work surfaces and equipment are thoroughly cleaned first and hands washed, and it recommends separate equipment kept for allergy-free preparation. It also reminds caterers that, unlike bacteria, allergens are not removed or destroyed by cooking.

That sheet is written for kitchens and does not mention steam wands. What it means for a coffee bar is the business's own allergen procedure to settle, with its regulator: a wipe and a purge between jugs is a hygiene habit and should not be assumed to be an allergen control. A bar that cannot be sure should say so to the customer who asks.

The steam wand, as one maker instructs

Sourced

Makers' instructions for the steam wand are consistent in outline and specific in detail. One home machine's instruction book says the wand should always be cleaned after texturing milk: wipe it with a damp cloth, then, with the tip over the drip tray, turn the steam on briefly to clear any milk left inside. If the holes in the tip block, the same booklet has the machine switched off and cooled before they are cleared with the pin on the tool it supplies.

That is one maker and one machine. Wiping and purging after every jug is the common habit behind bars, and the usual reasons given are that milk dries hard on hot metal and that milk drawn back into the wand as it cools is out of reach of a cloth; that is practice and reasoning, not something a document read for this page tested. A commercial machine's manual is the authority for that machine, including which cleaning product its maker permits.

Batch brew, and how long it is kept

CoffeeHQ explanation

Filter coffee brewed in quantity and held for service is the simplest drink on the menu and the easiest to neglect. The decisions are how much to brew, how strong, and how long a batch is offered before it is replaced.

The first two are arithmetic and taste, and the batch brew calculator does the arithmetic. The third is a house rule. Bars set a holding time for brewed coffee, and the times vary widely. No study of how brewed coffee held hot changes in the cup was read for this page, so no time is given here. What can be said is that the bars that manage it well write the brew time on the vessel and taste the coffee they are about to serve.

During service: the same drink, made the same way

CoffeeHQ explanation

What keeps the hundredth drink like the first. Each line is a habit baristas hold, with the reason usually given for it. Where a maker's instruction or a study stands behind one, the line says so; the rest is practice, and nothing read for this page tested it against taste.

1. The dose, by weight. The dose is weighed, or a grinder that doses by time is checked against a scale at chosen moments, because baristas find that a timed dose moves when the grind is adjusted and as the hopper empties. A dose that has crept is the cheapest fault to catch and the easiest to mistake for a grind problem.
2. A clean, dry basket. The basket is knocked out and wiped dry before every dose. The reasons given are that old grounds are stale coffee in the next shot and that a wet patch makes the bed uneven. Neither was tested in anything read for this page.
3. A puck routine that does not vary. Distribute, level and tamp the same way every time, and do no more than that. The page on puck preparation sets out which steps have evidence behind them. On a busy bar the value of a short routine is that two people can carry it out identically.
4. Brew promptly. The shot is started once the portafilter is locked in, and the drink is finished once the shot is pulled. The reasoning is that a prepared puck sitting against a hot group, or a shot waiting for its milk, is changing while it sits. That is practice; no holding time is given because none was found measured.
5. The steam wand, after every jug. Wiped and purged after every jug, as the section above sets out from one maker's instructions, with a cloth kept only for that job. Steam and the wand itself can scald: purge over the drip tray with hands clear of the tip.
6. Milk: steam what the drinks need. Cold milk is measured into the jug for the drinks in hand, in a jug sized for them. Milk steamed and not used is a waste a bar can see and count, and what may be done with it is a question for the business's written procedures, as the section on milk explains.
7. Fewer movements. Efficiency on a bar is mostly the absence of searching and waiting: tools returned to one place, the shot running while the milk steams, the next order read while the current one pours. Timing one drink from order to hand-over, and noting where finished espresso or milk stood waiting, shows where the time goes more reliably than trying to move faster.
8. Say what you are doing. Two people on one station call what they have started and what they need: which drink is on the group, whose milk is in the jug, what has run out. Orders are repeated back with the details that vary, which the next section takes up.
9. Taste on purpose. Somebody tastes the espresso at moments chosen in advance, describes it in the same few words each time (strength, acidity, bitterness, body) and writes it down. The description and the decision to serve are kept as two things: a shot can be described accurately and its merit still be a matter of opinion.

The same list works at home, with one person in every role.

Orders: where most errors actually happen

CoffeeHQ explanation

Most drinks that go wrong on a busy bar were made correctly and were the wrong drink. Drink names are not standard, a point the page on café ordering makes at length: a flat white, a cortado and a small latte overlap, and what a customer means by one of them depends on where they learned the word.

The working habits that deal with this are unglamorous. Repeat the order back with the details that vary. Agree, within the bar, what each drink on the menu is, so that two baristas hand over the same thing. Say the drink's name when passing it across. When a customer asks for something the bar does not make, describe what the bar does make that is closest, and let them choose.

Closing: the maker's routine, the waste, the last checks and the handover

Sourced

Closing is when the espresso machine is cleaned, and how is the maker's to say. The home machine whose instruction book was read for this page lights an indicator when a cleaning cycle is due and describes that cycle as back-flushing, separate from descaling: a cleaning disc and a tablet go in the basket, the machine runs water against them for about five minutes, and the cycle is repeated if the tablet has not dissolved. The same booklet has the shower screen and the inside of the group wiped with a damp cloth.

Not every machine can be back-flushed, and makers disagree about descaling: this booklet advises its owners to do it every month, and another maker's manual says it does not recommend descaling its machines, because the chemicals can corrode them and are hard to rinse out. The cleaning guide covers that disagreement. For a commercial machine, the manual and the service engineer decide the routine, including the detergent.

The rest of closing is the food business's own cleaning schedule, which its regulator will expect to see written down: fridges, milk jugs, drip trays, grinders' exteriors, floors. The grinder's inside is cleaned by whatever method its maker permits.

Before the waste goes out it is worth a look. How much milk was poured away, how many shots went down the sink and how many drinks were remade are the day's quality record, and a bar that counts them, even roughly, knows whether tomorrow's jug sizes and order-taking need to change. What must be thrown away, and when, is the food business's procedure and its regulator's rule.

The last checks are few, and they are the opening checks read backwards: the fridge closed and cold with tomorrow's milk in it, opened cartons dealt with as the procedures require, hoppers closed or emptied as the bar prefers, the machine left as its manual says to leave it, and whatever holds water or grounds emptied. Then a handover note: which coffee is in which grinder and at what setting, what drifted and what was done about it, what is running low, and anything about the machine that the next person should watch. The note is what turns the next opening from a rediscovery into a check.

Checking quality without a laboratory

CoffeeHQ explanation

A bar's quality check is mostly tasting, done on purpose and at set times. Tasting the espresso when the bar opens, after any grinder change and at intervals through the day is the whole of it for many cafés. Some weigh every shot, which catches a drifting dose before it is tasted. A few measure strength with a refractometer, which tells them how concentrated a drink is and nothing about whether it is good.

Two things make tasting more useful. One is tasting the same thing as a colleague and comparing words, which is what calibration means. The other is knowing that expectation changes what people taste, so that a barista who has just adjusted the grinder is not a neutral judge of the result. Tasting a shot without knowing which setting made it is easy to arrange between two people and removes the problem.

What each decision depends on

CoffeeHQ explanation

A summary of the page as a table. It is a model of how the decisions connect, not a set of recommendations.

Every row is a dependency, not an instruction. A food business answers to its own regulator and each machine to its own manual.

What this page leaves to the regulator and the manual

CoffeeHQ explanation

It gives no standard operating procedure, because none exists that applies to every bar. It gives no holding time for brewed coffee, no interval for re-dialling, no cleaning schedule and no detergent, because each would be a figure nobody measured or a decision that belongs to a maker or a regulator.

It reports two food-safety texts for what they say, one a United States model code and one United Kingdom guidance. It is not a statement of the law in any place and it is not compliance advice: local rules apply, and it does not replace a food business's own food-safety management or its regulator's advice. It says nothing about whether steamed milk may be kept or reused, because neither text does. Nothing here certifies anybody as a barista, and CoffeeHQ has not run a café.

What to do next

• The workflow lesson — The same ground as a lesson, with tasks to do at the machine, a session log for finding out how far your shots move when nothing is changed, and self-checks.
• Espresso dial-in assistant — Turns a shot's dose, yield, time and taste into one change to try next.
• Cleaning and descaling equipment — Why cleaning and descaling are different jobs, and where makers disagree.
• Steaming and frothing milk — What the steam wand is doing to the milk, and how to judge the result.
• Espresso puck preparation — The step between the grinder and the group, and which parts of it are evidence.