How Korean Traditional Alcohol Is Made: Brewing Guide

Every Korean traditional alcohol begins with just three ingredients:

• Rice (쌀) — The starch source. Different rice varieties (non-glutinous, glutinous, brown) produce different flavor profiles. The rice must be washed, soaked, and steamed — never boiled — to properly gelatinize the starch.
• Nuruk (누룩) — The fermentation starter. This is the single most important difference between Korean and Japanese brewing. Nuruk is a wheat cake inoculated with a complex community of wild molds, yeasts, and bacteria. It provides both the enzymes to convert starch to sugar and the yeast to convert sugar to alcohol — all in one package.
• Water (물) — Quality matters enormously. Traditional brewers prize clean, mineral-rich spring water. The mineral content influences fermentation speed and final flavor.

Some recipes add supplementary ingredients — herbs, flowers, fruits, honey — but rice, nuruk, and water are the universal foundation.

Understanding nuruk is the key to understanding Korean brewing:

Because nuruk contains a diverse microbial community, no two batches are exactly alike. This natural variation is part of what gives Korean traditional alcohol its distinctive, terroir-like character. Each brewer's nuruk is different, and nuruk quality is the single biggest factor in final alcohol quality.

For a detailed comparison with Japanese sake, see our rice wine vs sake guide.

The core Korean brewing process follows these steps:

1. Washing and soaking (세미, 침지) — Rice is washed repeatedly until the water runs clear, then soaked for 2-12 hours depending on the rice type. This hydrates the grain evenly.
2. Steaming (증자) — The soaked rice is steamed (never boiled) in a traditional steamer (시루). Steaming gelatinizes the starch without making the rice mushy, creating the ideal texture for nuruk enzymes to work.
3. Cooling (냉각) — Steamed rice is spread out and cooled to about 25-30 degrees C. If it is too hot, it will kill the microorganisms in the nuruk.
4. Mixing (혼합) — Cooled rice, crumbled nuruk, and water are combined in a fermentation vessel — traditionally an onggi (옹기, earthenware crock). The ratio of rice to nuruk to water varies by recipe but typically falls around 10:1:10 by weight.
5. Fermentation (발효) — The mixture ferments for 7 to 30 days. During this time, two processes happen simultaneously: nuruk enzymes break starch into sugar (saccharification) while yeasts convert sugar to alcohol (alcoholic fermentation). This "parallel fermentation" is unique to East Asian brewing and enables higher alcohol content than Western beer-style sequential fermentation.
6. Straining / Pressing (거르기 / 압착) — The fermented mash is strained to separate liquid from solids. Coarse straining produces makgeolli; fine pressing through cloth produces cheongju.

Many premium Korean traditional alcohols use a multi-step fermentation called "deotseul" (덧술, literally "additional brew"):

• Single brew (단양주) — Everything goes in at once. Simplest method. Used for everyday makgeolli.
• Two-step (이양주) — An initial starter (밑술, mitsul) ferments for 3-5 days, then a second addition of rice and water is made. The active starter accelerates the second fermentation and produces a cleaner, more complex result.
• Three-step (삼양주) — Three successive additions. Produces even higher alcohol and more refined flavors. Many high-end yakju and cheongju use this method.

Each additional step adds labor and time but yields progressively more complex, higher-alcohol, and smoother results. The finest traditional Korean alcohols use three or more brewing stages.

Traditional soju is produced by distilling the fermented rice mash (or sometimes the pressed cheongju):

• Pot still (소줏고리) — The traditional Korean still is called sojutgori. It sits on top of a cauldron containing the mash. Steam rises through the mash, carrying alcohol vapor, which condenses in a water-cooled basin above. The condensed liquid is soju.
• Single distillation — Most traditional soju is distilled only once, preserving more grain flavor and character from the original fermentation. This contrasts with vodka or neutral spirits, which are distilled multiple times for purity.
• ABV range — Single pot distillation typically yields 25-45% ABV, depending on how the distillation is managed.
• Aging (optional) — Some distillers age their soju in onggi crocks or oak barrels for months or years, developing smoother, more complex flavors.

This process is entirely different from commercial (diluted) soju, which starts with industrially produced ethanol and simply adds water and flavoring.

The filtration step is what separates cheongju (clear rice wine) from makgeolli:

1. Pressing (압착) — The fermented mash is placed in a cloth bag and pressed. The clear liquid that flows through is cheongju. The cloudy residue left in the bag becomes makgeolli when mixed with water.
2. Settling (침전) — After pressing, cheongju may be left to settle further. Fine particles slowly drop to the bottom over days or weeks.
3. Fine filtration (정제) — Some producers use additional filtration for crystal clarity. Others prefer a slightly hazy "raw" cheongju (생주, saengju) that retains more flavor complexity.

The pressing method directly affects quality. Gentle, slow pressing extracts cleaner liquid. Aggressive pressing extracts more volume but introduces bitter compounds from the lees.

Modern Korean brewing has introduced several changes to the traditional process:

Neither approach is inherently better. Traditional methods produce more character and variation; modern methods produce more consistency and scale. Many of the best contemporary Korean brewers blend both — using traditional nuruk and recipes in modern, temperature-controlled facilities.