Kalkulator Resep Air Seduh (SCA + DIY)
Buat air kopi dari air suling atau RO ditambah garam Epsom dan baking soda untuk mencapai target kesadahan SCA.
Kalkulator
Sesuai target
GH 68 ppm dan KH 40 ppm keduanya berada di dalam jendela SCA (GH 17–175, KH 30–70). Ini adalah air seduh yang seimbang dan mendukung ekstraksi.
Lebih mudah: buat konsentrat
Dosis langsung kurang dari satu gram dan sulit ditimbang. Sebagai gantinya, larutkan 8.37 g garam Epsom + 3.36 g baking soda dalam 1 L air suling (konsentrat stok). Lalu tambahkan 20 mL konsentrat per liter air seduh — satu liter konsentrat mengolah sekitar 50 L.
Air yang hanya menggunakan baking soda menambah natrium: sekitar 0,46 mg/L Na per ppm KH (≈ 18.4 mg/L di sini). Untuk air rendah natrium, gunakan kalium bikarbonat sebagai gantinya.
Target GH bersifat indikatif — ada dua tabel SCA (standar 2009 berpusat di sekitar 68 ppm; bagan kemudian membentang 50–175 ppm). Sesuaikan dengan selera.
Tentang kalkulator ini
Water is most of what is in your cup, and its mineral content changes how coffee extracts and tastes. This calculator builds brewing water from a clean base — distilled or reverse-osmosis (RO) water, which is almost mineral-free — by adding two cheap minerals: Epsom salt for general hardness (GH) and baking soda for alkalinity (KH). Set your batch size and your GH and KH targets and it returns the grams to add, plus an easier make-ahead concentrate, and tells you whether you have hit the SCA water windows.
Cara membaca hasil Anda
GH (general hardness) is the magnesium and calcium that drive extraction; KH (alkalinity, also called carbonate hardness) is the buffering that tames acidity. The SCA targets are GH ≈ 68 ppm and KH ≈ 40 ppm (both as CaCO₃), with a total dissolved solids (TDS) target around 150 ppm and pH near 7.0. Because the direct doses for a 1 L brew are well under a gram, weighing them is fiddly — so the calculator also gives a stock concentrate you dissolve once and then dose by the millilitre.
Cara penghitungan
Epsom salt (MgSO₄·7H₂O) raises GH by 406 ppm per gram per litre; baking soda (NaHCO₃) raises KH by 596 ppm per gram per litre, both expressed as CaCO₃. So grams = target ppm × litres ÷ factor. The concentrate scales the per-litre dose up by a fixed factor so it is weighable, and the dose-per-litre is the inverse of that factor. Baking soda also adds sodium — roughly 0.46 mg/L of Na for every ppm of KH.
Contoh perhitungan
1 litre of distilled water, targeting the SCA defaults: GH 68 ppm and KH 40 ppm.
Add about 0.17 g of Epsom salt and 0.07 g of baking soda (≈ 0.23 g total). Easier: dissolve 8.4 g Epsom + 3.4 g soda in 1 L of distilled water as a concentrate, then add 20 mL per litre of brew water (one litre of concentrate treats ~50 L).
Pertanyaan yang sering diajukan
Why start from distilled or RO water?
Distilled and RO water are almost mineral-free, so the minerals you add are the entire recipe and the result is repeatable. Tap water already contains varying minerals, so adding more on top is guesswork unless you have a water report.
Why a concentrate instead of dosing the dry powders?
For a single litre the doses are a fraction of a gram, which most kitchen scales cannot weigh accurately. Dissolving a larger amount once in a stock concentrate lets you dose precisely by the millilitre for every future batch.
Is baking soda the best source of alkalinity?
It is the cheapest and most available, but it adds sodium — about 0.46 mg/L of Na per ppm of KH. If you want to avoid sodium, potassium bicarbonate raises KH the same way without it.
My GH target looks off compared to another chart — why?
There are two SCA reference tables. The 2009 standard centres GH near 68 ppm; later charts allow a wider 50–175 ppm band. Both are acceptable starting points — treat GH as indicative and dial it to taste.
Sumber
Ditinjau oleh Tim YouCalc · Terakhir ditinjau
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