Sake · Production · Study guide
Pressing & Finishing
A study guide to what happens after fermentation — pressing and its fractions, filtration, pasteurisation and the nama family, dilution, maturation and blending.
When fermentation ends, the brewer has a thick, milky mash — sake and spent solids together. Everything from here on is subtraction and adjustment: separating the clear sake, deciding whether to filter it, whether to pasteurise it, how much to dilute it, and how long to rest it. None of these steps adds flavour; each one removes or stabilises something, and each is a fork in the road that creates a named style. Skip the charcoal and you have muroka; skip the pasteurising and you have nama; skip the water and you have genshu.
Fix two things: pressing (how the sake is separated from its lees, and why the fraction matters) and the nama family (which of the two pasteurisations a sake has, or hasn't, had). The rest of the finishing line hangs off those.
The one thing to fix first: finishing is a series of "leave it out" choices
Standard sake is pressed, filtered, pasteurised twice, rested and diluted. Every named finishing style is that sequence with one step removed:
- Leave the sake cloudy (coarse filter) → nigori
- Don't charcoal-filter it → muroka (keeps its natural colour and flavour)
- Don't pasteurise it → namazake (fresh, fragile, needs refrigeration)
- Don't dilute it → genshu (undiluted, ~18–20% ABV)
Learn the standard line, and each style is just one deliberate omission from it. These labelling terms are covered in reading a sake label and speciality styles.
Pressing, and the three fractions
Pressing (jōsō, shibori) squeezes the clear sake out of the mash, leaving behind the white lees (sake kasu). How gently it is done, and which part of the run you keep, both affect quality.
| Method | How | Character |
|---|---|---|
| Yabuta (assakuki) | Automatic accordion-press; the industry standard | Efficient, clean, consistent |
| Fune (funa-shibori) | Traditional box press, gentle weight | Softer, more delicate; premium |
| Shizuku / fukuro-zuri | Bags hung to drip under gravity, no pressure | The gentlest; competition and flagship sake |
The run also divides into three fractions, in order:
- Arabashiri — the first, free-running sake; lively, cloudy, exuberant.
- Naka-dori (naka-gumi) — the middle, the most balanced and refined; this is the fraction bottled for competitions.
- Seme — the last, hardest-pressed sake; coarser and more robust.
If a bottle boasts naka-dori, it is claiming the best slice of the pressing.
Key facts
| Pressing | Separates clear sake from the lees (sake kasu) |
| Gentlest press | Shizuku / fukuro-zuri — free drip, no pressure |
| Best fraction | Naka-dori — the balanced middle of the run |
| Charcoal fining | Removes colour and off-notes; muroka = not charcoal-filtered |
| Pasteurisation | Usually twice, ~60–65 °C, to kill enzymes and hiochi bacteria |
| Dilution | Down to ~15% ABV; genshu = undiluted |
Pasteurisation, briefly
Most sake is pasteurised (hi-ire) — gently heated to around 60–65 °C — to deactivate lingering enzymes and kill hiochi bacteria, a spoilage lactic-acid bacterium that survives in alcohol. It is normally done twice: once after pressing and filtering, and again at or before bottling. Each pasteurisation the brewer skips leaves a fresher but more fragile sake that must be kept cold — the nama family, below.
In this guide
The full guide below goes deeper into the finishing choices and the styles they make:
- The nama family — namazake, nama-chozō, nama-zume — decoded
- Filtration and charcoal fining, and what muroka keeps
- Dilution and genshu; adjusting the final balance
- Maturation, koshu and cedar-cask taru-zake
- Blending, and why it is not a dirty word
- Classic exam questions
The nama family, decoded
The two pasteurisations happen at two points — before storage and at bottling — so which ones a sake receives gives four possibilities:
| Style | First pasteurisation (before storage) | Second (at bottling) |
|---|---|---|
| Standard sake | ✔ | ✔ |
| Namazake (生酒) | ✘ | ✘ |
| Nama-chozō (生貯蔵) | ✘ | ✔ |
| Nama-zume (生詰) | ✔ | ✘ |
- Namazake is never pasteurised — the freshest, most vivid, most fragile sake, sold cold and drunk young.
- Nama-chozō ("stored raw") is kept unpasteurised, then pasteurised once as it is bottled — fresh in character but a little more stable.
- Nama-zume ("bottled raw") is pasteurised once before resting, then bottled without a second heating — the logic behind hiyaoroshi, the autumn release of sake that rested over summer.
Filtration and charcoal fining
After pressing, cloudy new sake is usually left to settle so gross lees drop out, then often charcoal-fined — fine powdered carbon is stirred in to strip colour and any rough or off notes, then filtered out. It is effective but blunt: it also removes some desirable aroma and flavour. Sake that skips it is muroka (無濾過), which keeps its faint natural straw-gold colour and a fuller, more textured flavour. Muroka often appears alongside nama and genshu on characterful, hands-off sake: junmai muroka nama genshu is the label of a big, raw, undiluted style.
Dilution and genshu
Sake ferments to 18–20% ABV, stronger than most people want to drink, so brewers dilute it with water to around 15%, balancing the sake as they go. Bottled without this step, it is genshu (原酒) — undiluted, hot and full, often 18%+. The dilution water is chosen with the same care as the brewing water, and its mineral character leaves a regional stamp on the finished sake (regions of Japan).
Maturation, koshu and taru-zake
Most sake is rested for around six months — typically over the summer after a winter brew — to lose its rough edges and settle before shipping; sake is generally meant to be drunk young and fresh. Two deliberate exceptions:
- Koshu (古酒) — sake aged on purpose, often for two years or more, which turns amber and takes on honeyed, nutty, sherried, savoury notes.
- Taru-zake (樽酒) — sake rested in Japanese cedar (sugi) casks, which lend a fragrant, woody, slightly resinous lift.
Blending
Finally, most commercial sake is blended — different tanks, pressings and even vintages married for consistency of house style and to hit a target volume. Far from a compromise, blending is how a brewery makes its flagship taste the same year on year, and how it balances the lively arabashiri against the sturdier seme into one coherent sake.
Classic exam questions
- What is the gentlest pressing method? — shizuku / fukuro-zuri: bags dripping under gravity, with no pressure.
- Which pressing fraction is prized for balance? — naka-dori (the middle of the run).
- What does muroka mean? — not charcoal-filtered; the sake keeps its natural colour and flavour.
- How many times is sake usually pasteurised, and why? — twice, to deactivate enzymes and kill hiochi bacteria.
- What is namazake? — unpasteurised sake — fresh and fragile, needing cold storage.
- What is genshu? — undiluted sake, at its full ~18–20% ABV.
Learn the standard finishing line and every "raw", "undiluted", "unfiltered" sake reads as the same sequence with one honest step left out.