A bean-to-cup machine grinds whole beans as it brews, so any bag of whole beans works in it. The two things worth choosing are the roast level the roaster states and the bag size, because these machines get through beans quickly. 1,220 in-stock coffees on Bean Clarity from 211 UK and Irish roasters state a medium or medium-dark roast, with a median of £34.00 a kilo across those priced in pounds, and 5,093 in-stock coffees are sold in a 1 kg bag, at a median of £36.30 a kilo on that bag.
This post covers one kind of machine. For the choice as a whole, from how you brew to what the label leaves out, start with how to choose coffee beans.
What the machine needs
Whole beans, not pre-ground: the machine grinds its own. The hopper on top typically holds a few hundred grams, so beans sit in it for days, and many machine makers advise against very oily beans because they can clog the built-in grinder. Bean Clarity records what the roaster states about roast level and nothing more; where nothing is stated the site says Not stated rather than guessing, and what Not stated means explains why. Only 26% of in-stock coffees state a roast level at all, so the label is worth looking for.
Roast level: what roasters state and what it costs
Stated medium and medium-dark roasts have a median of £34.00 a kilo, against £40.19 a kilo for stated light and medium-light roasts and £38.00 a kilo across every coffee priced in pounds. Medium roasts come out cheaper at the median. The whole price picture is in what speciality coffee should cost.
316 in-stock coffees state a dark roast. Very dark roasts are often the oily ones the machine makers warn about; Bean Clarity does not test this, and records only the roast level the roaster states.
To see them, the roast filter lists every stated medium roast and every stated medium-dark roast.
Bag size: why many owners buy a kilo
At around 10 g of beans a drink, four or five drinks a day get through a 250 g bag in about a week. 92% of coffees sold in more than one size are cheaper per kilo in the bigger bag, by 15% at the median. Why a bigger bag costs less shows where that saving comes from. Of the 5,093 in-stock coffees sold in a 1 kg bag, 1,021 state a medium or medium-dark roast.
A kilo bag stays open for longer than a 250 g one. Most roasters print a roast date on the bag; Bean Clarity shows what the roaster states and does not judge freshness.
Espresso roasts in a bean-to-cup machine
Bean-to-cup machines brew under pressure, so a stated espresso roast works in them too: 1,824 in-stock coffees from UK and Irish roasters state one. Choosing coffee beans for espresso at home covers what they cost against filter roasts.
Where to start on the catalogue
The beans list can show every stated medium roast in stock with a price, cheapest per kilo first. Nothing in that list is ordered by quality, because Bean Clarity holds no tasting data; every coffee’s page shows each bag size it is sold in.
No roaster can pay to change a figure or the order of a list; any paid placement is labelled Sponsored.