The ultimate barista and tea compendium: From botany to the cup
Coffee and tea boast a history spanning millennia and offer an aromatic complexity that rivals that of wine. However, perfect enjoyment often hinges on details such as grind size, water temperature, or storage. This guide provides you with the scientifically sound tools for barista-level results.
1. The World of Coffee: Botany & Roasting
The taste of your coffee begins with cultivation and is significantly shaped by roasting.
Arabica vs. Robusta
Although there are over 100 types of coffee, two dominate the market:
- Coffea Arabica: Grows as a highland coffee (600–2000m). Due to the cooler climate, the cherries ripen more slowly, resulting in delicate fruit notes, complex acidity, and less caffeine.
- Robusta (Coffea Canephora): Grows at lower altitudes and is more resistant. Its flavor is stronger, often earthy or woody, and essential for a firm crema in espresso.
The roasting process: The Maillard reaction
Only through heat are over 800 aromatic substances created from the neutral raw coffee:
- Light roast (Light/Cinnamon): Emphasizes the natural acidity and the "terroir" (origin). Ideal for filter coffee (Third Wave Coffee).
- Medium roast (City/Full City): The balancing act between acidity, sweetness, and roasted aromas. The everyday classic.
- Dark roast (French/Italian): Acidity is reduced, bitterness and roasted aromas dominate. Typical for Italian espresso.
2. Extraction: Grind size & preparation methods
Coffee brewing is a dissolution process (extraction). The most important basic rule is: the finer the grind, the larger the surface area and the faster the ingredients dissolve.
- Underextraction: Grind too coarse or time too short. Result: Sour, watery.
- Over-extraction: Grind too fine or brewing time too long. Result: Bitter, astringent.
The parameters for common methods
| method | Grind size | Time | principle |
|---|---|---|---|
| espresso | Fine | 25–30 sec. | High pressure (approx. 9 bar) |
| Hand filter | Agents (such as sea salt) | 2–4 min. | Gravity |
| French Press | Rough | 4 min. | Full Immersion (constant contact) |
3. Hardware check: Mills & machine types
Investing in a good machine is hardly worthwhile if the grinder is neglected. Ground coffee oxidizes within minutes.
The centerpiece: The coffee grinder
- Blade grinder: Works like a blender. Produces uneven grounds ("dust and boulders"), leading to simultaneous over- and under-extraction. Not recommended.
- Flat burrs: Two discs. Produces a very homogeneous grind for clear, fruity aromas.
- Conical burrs: Quieter and cooler. Creates a bimodal particle distribution for more body in the espresso.
Comparison of machine types
- Portafilter: The gold standard for true crema and parameter control. Requires craftsmanship.
- Fully automatic: Convenient, but produces more "Schümli coffee" (coffee cream) than real espresso.
- Capsule system: Consistent and convenient, but often expensive per kilogram and waste problems.
4. Beverage Lexicon: Espresso, Flat White & Co.
The menu in a café can often be confusing. Here we define the most common coffee specialties.
- espresso
- 25–30 ml of water, forced under high pressure through approximately 7–9 g of finely ground coffee. Characteristic: The hazelnut-brown crema.
- Ristretto
- A "shortened" espresso with less water (15–20 ml). More intense and less bitter.
- Americano
- An espresso that's been diluted with hot water. Important: Add the water first, then the espresso (to preserve the crema).
- cappuccino
- One-third mix: Espresso, hot milk, creamy milk foam.
- Flat White
- Usually a double ristretto/espresso with very fine-pored milk foam ("microfoam"). The milk content is lower than in a latte, therefore it's stronger.
- Latte Macchiato
- "Stained milk". First milk/foam into the glass, then espresso, so that three layers form.
5. The World of Tea: Varieties & Preparation
Real "tea" always comes from the Camellia sinensis plant. The difference lies in the oxidation process.
The categories
- White tea: Minimally processed, only dried. Mild and floral.
- Green tea: Oxidation stopped by heat. Grassy, fresh, nutty.
- Oolong: Partially oxidized (between green and black). Huge variety of flavors.
- Black tea: Fully oxidized. Strong, malty, dark.
Preparation tips
Water temperature is everything: Boiling water (100°C) is usually only suitable for black tea and herbal teas. Green tea often only needs 60°C to 80°C, otherwise it becomes bitter.
6. Tea expert knowledge: Matcha, storage & decaffeination
Matcha: The green gold
Matcha is powdered shade-grown tea. Because you drink the whole leaf, you ingest a particularly high amount of antioxidants and caffeine. The taste is umami (savory-sweet).
The 4 enemies of tea (storage)
- Light: Destroys chlorophyll.
- Air: Leads to post-oxidation (loss of aroma).
- Moisture: risk of mold.
- Foreign odors: Never store tea next to spices or coffee!
Decaf
There are two high-quality methods for removing caffeine without chemicals:
- CO2 process: Caffeine is washed out using carbon dioxide under pressure.
- Swiss Water Process: Uses only water and reverse osmosis. Very gentle, but complex.
