Sources · Checked October 2026
Where the
numbers come from.
Brewing guides, original drink descriptions and the recordings behind the café radio.
Chain-inspired drinks use Groundwork’s own home proportions, not official store formulas or nutrition values. Caffeine is approximate; multi-cup batches identify the serving. Cup layers show the ingredients, not an exact measurement scale.
Coffee-shop recipes
- Starbucks at Home recipesFlavour references for home adaptations. Individual recipes link to their drink reference.
- Dunkin’ Signature LattesCaramel Craze, Cocoa Mocha and Blueberry Crisp flavours and toppings.
- Dunkin’ butter pecan drinksButter pecan iced coffee and Turtle latte flavour combinations.
- Iced Dutch FavesGolden Eagle, Caramelizer, Annihilator and Kicker ingredient descriptions.
- McCafé menuFrappés, iced mocha and caramel macchiato flavour references.
- Egg safetyUse pasteurized eggs for the uncooked egg-coffee topping.
Café radio
- Vibey’s music catalogFour CC0 Free Music Archive recordings selected from Vibey’s catalog, served with Groundwork for reliable playback. Artist, source and licence links appear in the music settings while a track is selected.
Espresso & the machine
- Defining the ever-changing espressoHeritage espresso definition: dose, 90.5–96.1 °C, 9–10 atm, 20–30 s.
- Espresso extraction time & ratio18 g in, 36 g out, 25–30 s starting recipe.
- Dialing in espresso by tasteSour → finer, bitter → coarser; sour-and-bitter points to channeling.
- Espresso extraction yield explainedThe 18–22% extraction window used by the bar’s compass.
- EspressoBezzera 1901, Pavoni 1905, Gaggia’s lever and crema.
- History of espresso machines
Milk
- How to steam milk for lattes and cappuccinosStretch times by drink.
- How to steam milk
- The science of milkLactose sweetness peaks near 60 °C.
Coffee in 2026
- Coffee: World Markets and Trade (July 2026)2026/27 forecast: 189.7 M bags; country and arabica/robusta tables used on Beans.
- Coffee tops beverage charts again; specialty hits new high47% had an espresso drink in the past week.
- More Americans drinking specialty coffee and ordering by appCold coffee among past-day drinkers: 21%.
- Why is coffee back in bullish modeArabica record $4.3795/lb (Oct 2025); 2026 slide and rebound.
- Best of Panama auction sees world-record price2025 washed Geisha at US$30,204 per kg.
- The 13 biggest coffee trends of 2026Protein, pistachio, savoury-sweet, espresso tonic.
- Coffee shop trends in 2026
Beans, species & processing
- Genomic data define species delimitation in Liberica coffeeLiberica, excelsa (C. dewevrei) and C. klainii as separate species.
- The search for climate-resilient coffeeExcelsa in Uganda; stenophylla.
- New coffee species to stand up against climate impact
- Arabica and robusta: meaning and curiositiesCaffeine and altitude ranges.
- The guide to coffee processing methods
- Washed vs natural process coffee
- Coffee roast levels chartCrack temperatures vary by source: first ~196–205 °C, second ~224–230 °C.
- Types of coffee roasts
Brewing & grind
- Coffee grind size chartMicron ranges per method.
- Coffee grind size chart
- James Hoffmann’s V60 recipe (write-up)15 g : 250 g pulse pours.
- James Hoffmann’s AeroPress recipe (write-up)11 g : 200 g, 2 min, swirl, press.
Drinks & caffeine
- CortadoCortado and Gibraltar glass.
- Vietnamese coffee decodedEgg coffee (1946), salt coffee, coconut coffee.
- Caffeine content by brew methodUSDA-based per-ounce values.
- Spilling the beans: how much caffeine is too much?400 mg a day for healthy adults.
About the bar’s shot
The espresso machine is a teaching model, not a physics simulation. Grind size and dose set how much the puck resists water; that sets pressure and flow. Ratio, resistance and channeling then set extraction and strength, calibrated so a dialed-in 1:2 shot lands near 20% extraction and 10% strength. Real coffees shift these numbers: use them to learn the direction of each change.