In this issue: the three things printed on a Costa Rican bag and what each one is actually claiming, a grinder launch next to an explainer on what the burrs inside it are doing, three credible authorities who cannot agree on how to bloom, and two studies that reach opposite conclusions about paper filters.
Last issue covered why Costa Rican coffee looks the way it does — a 1989 ban on Robusta and a micro-mill boom that put farm names on bags. This one is about the three things actually printed on that bag.
The first is a grade. Costa Rican green coffee is graded by the altitude it grew at rather than by defect count: Strictly Hard Bean means 1,200 metres and above, Good Hard Bean covers roughly 1,000 to 1,200, and Medium Hard Bean sits below that. The reasoning is that cherries ripen more slowly in cooler air and produce a denser bean. So SHB on a bag is an elevation claim, and elevation is a reasonable proxy for acidity and sweetness — but it is not a cupping score, and it tells you nothing about processing or roast date.
The second is a region, and it is partly another elevation claim. Tarrazú, the largest and the name most likely to be on your bag, runs roughly 1,200 to 1,900 metres. Tres Ríos, the smallest and most prestigious, sits between about 1,200 and 1,650. West Valley starts much lower, around 700, and Turrialba lower still — which is why a Turrialba coffee reads gentler and lighter-bodied than a Tarrazú off the same shelf. Different, not worse.
The third is a varietal, and this is where Costa Rica gets interesting. Caturra and Catuaí do most of the work, but the one worth seeking out is Villa Sarchí: a natural dwarf mutation of Bourbon found near the town of Sarchí in the West Valley in the 1950s. It is the same single-gene compactness that gave Brazil Caturra and El Salvador Pacas — a short plant with short internodes, plantable at 5,000 to 6,000 trees per hectare on steep ground, and tolerant of strong wind, which is why it ends up on exposed ridges. World Coffee Research rates its cup quality good at high altitude. It is also susceptible to leaf rust, which is why it never travelled far, and why breeders crossed it with Timor Hybrid to found the entire Sarchimor family.
Costa Rica harvests November through March, which puts the peak-freshness window January through June. In August you are outside it, so buy on the roast date rather than on a harvest claim and wait for the new year's arrivals.
The second-generation Opus moves to a 48mm stainless conical burr set from the original's 40mm, swaps stepped clicks for a stepless adjustment dial, and ships two catch cups — one for brewed, one for espresso. At $199.95 it stays in the same do-everything bracket, and Fellow puts an espresso dose at around nine seconds.
Conical burrs produce more fines — the sub-200-micron particles thrown off every time a bean fractures — which is why conical grinds tend to brew fuller-bodied and suit espresso, while a flat burr's more even particle distribution generally reads lower in astringency. The free part you can do today is chirp calibration: close the burrs until you hear them touch, then back off just until the sound stops.
Slow Pour Supply's HIFLUX papers blend European wood pulp with long lyocell fibres in a three-dimensional structure meant to resist clogging, and the point for a home brewer is that paper choice changes drawdown time and clarity like any other parameter. At $9 for 15 sheets it is the cheapest experiment on the shelf: same coffee, same grind, same recipe, two papers, compare.
James Hoffmann swirls, Barista Hustle's own experiments found stirring more effective at raising extraction (though less so at doses as low as 15g), and World Brewers Cup finalists are increasingly dropping a distinct bloom in favour of pulse pours. German Brewers Cup champion Nicole Battefeld-Montgomery's answer is that there is no single best option and that preparing the coffee bed before the first pour matters more than which agitation you pick.
Under-extracted coffee is sour, salty, short in the finish and missing sweetness, because acids and salts dissolve more readily than sugars do — you stopped too early. Over-extracted coffee goes dry and bitter, because you kept going past the point where only the good things came out.
Bars in Melbourne and Sydney are pulling shots in advance, chilling them and pouring to order, and the operators doing it say blind milk drinks are hard to tell from freshly pulled — clean and sweet rather than punchy, and consistent from first sip to last. That is practitioner testimony rather than published data, but it is testable at home: pull two shots tonight, refrigerate one, compare them in milk tomorrow.
A Peking University team ran a Mendelian randomisation analysis across UK Biobank and MiBioGen data and found filtered coffee significantly associated with lower HbA1c, while five other consumption patterns — instant, decaf, sweetened, milk-added, ground — were not. The proposed route is the gut: filtered coffee tracked with more of the bacterium Veillonella, which accounted for roughly 43% of the effect.
In a cross-sectional study of 1,079 coffee-drinking adults near Bari, Italian-style unfiltered coffee showed an inverse dose-response with metabolic dysfunction-associated steatotic liver disease, odds ratios falling from 0.479 at one cup a day to 0.407 at four to six, with the authors crediting the diterpenes and oils that paper removes. Read alongside the study above, the honest conclusion is that filtration trades one measured outcome for another rather than winning — and neither study can show causation, both being observational.
If the study above has you reaching for the moka pot, the fix for the bitter cup it usually makes is free: fill the base with already-boiled water to roughly halfway up the pressure valve so the pot spends less time on the flame, keep the heat gentle, don't grind as fine as espresso, and kill the heat the moment coffee starts flowing. Residual heat finishes the brew.
Three of this week's entries cost nothing to try — a chirp calibration, a bloom you agitate differently, a moka pot you take off the heat sooner — which is the kind of week we like. If any of it was useful, forward this issue to a coffee-obsessed friend or send them the sign-up page. See you next Thursday.
Thanks for reading ☕