Cold Brew 101 — Ratio, Timing, Storage

Cold brew = extraction dingin selama 12-18 jam. Berbeda dari iced coffee (brew panas lalu dinginkan). Chemistry beda: senyawa pahit + asam rendah karena butuh panas untuk larut.

Kenapa Cold Brew Special?

• Low acidity (67% lebih rendah dari hot brew)
• Low bitter (same reason — senyawa pahit kurang soluble di dingin)
• High sweetness + chocolate yang naturally extracted
• Low caffeine per ml — concentrate biasa dilute 1:1 saat sajikan

Gear Minimal

• Jar/carafe 1L (Mason jar, OXO, Takeya)
• Fine mesh strainer atau cheesecloth (filter kopi)
• Grinder — coarse setting
• Timbangan
• Kulkas untuk steep

Optional: Cold brew maker khusus (Hario, Toddy) — mengintegrasikan filter.

Resep Standard

Concentrate (1 Liter)

• Dose: 200g kopi (coarse grind)
• Water: 1000ml air dingin / filtered
• Rasio: 1:5
• Time: 14-16 jam di kulkas
• Yield: ~800ml concentrate

Dilute Saat Sajikan

• Concentrate 1 bagian + air es 1 bagian = iced cold brew standard
• Concentrate 1 + milk 1 = cold brew latte
• Concentrate 1 + tonic water = kopi tonic (trendy)

Effective ratio final ~1:10, similar dengan hot brew tapi rasa VERY different.

Step-by-Step

1. Grind coarse (seperti gula kasar). Grind halus = sediment banyak + over-extract bitter bahkan di dingin.
2. Kopi bubuk + water dingin di jar. Aduk supaya semua bubuk basah.
3. Tutup rapat (oxygen exposure = stale faster).
4. Kulkas 14-18 jam. 14 = balanced, 18 = sweeter + body.
5. Filter dengan cheesecloth atau mesh — 2 layer pass untuk clean.
6. Store di bottle glass — lasts 1 minggu di kulkas.

Bean Selection

Cold brew best dengan body-heavy bean:

• Gayo wet-hulled — chocolate + earthy lebih pronounced di cold
• Mandailing — tobacco + cocoa classic
• Flores Bajawa — nut + chocolate
• Brazil Santos — classic cold brew base (sweet + nutty)

Avoid: Bright Ethiopian light roast — acidity yang disuka hilang di cold, tinggal "bland".

Roast Level

• Medium-dark optimal — chocolate + sweet naturally extracted di cold
• Light roast bisa tapi flavor muted — bukan cold brew classic style
• Dark roast strong tapi risk burnt-stale notes

Variasi Recipe

Japanese Iced (Flash Brew)

• Bukan cold brew tradisional
• Brew hot V60 dengan es batu di server (50% weight water replace es)
• Result: bright acidity + fruity preserved (beda dari cold brew)

Nitro Cold Brew

• Cold brew + infused N2O → creamy texture, no sugar needed
• Butuh nitro canister atau tap system. Mahal di rumah.

Cold Brew Toddy

• Device khusus Toddy (plastic system)
• Result same, built-in filter easier workflow

Storage

• Concentrate: 1 minggu di kulkas (glass bottle, sealed)
• Dilute ready-to-drink: 3 hari di kulkas
• Freeze: Bisa, tapi texture lose freshness setelah thaw

Common Mistakes

1. Grind terlalu halus — bitter bahkan di cold. Fix: coarse grind.
2. Pakai air hangat — accelerate extraction tidak beraturan. Fix: air dingin.
3. Steep terlalu lama (>24 jam) — over-extract + stale. Max 18 jam.
4. Tidak filter 2x — sediment ruins mouthfeel. 2 pass cheesecloth minimum.

Rasio + Timing Tabel

Goal	Rasio	Time	Karakter
Classic balanced	1:5	14h	Sweet + chocolate
Light refresh	1:7	12h	Fruity + clean
Heavy concentrate	1:4	16h	Syrupy, dilute lebih
Kopi susu ready	1:5	14h	+ susu 1:1

Why Cold Brew di Indonesia?

Iklim tropis 28-34°C — cold brew sempurna untuk sore/malam. Tahan seminggu = bikin sekali, nikmat sepanjang minggu. Low cost per serving (~Rp 5-8k dari bean specialty Rp 150k/200g).

Cold brew pair sempurna dengan dessert Indonesia — klepon, es campur, atau sebagai base kopi susu Tuku-style.

Jadi kalau bosan V60, rotate ke cold brew weekly. Flavor dimension baru dari bean yang sama.