Cleaning & Sanitation
Clean then sanitise — the two-step discipline that decides whether a batch turns out clean or infected. The chemicals, contact times, the 80 °C rule, and per-stage routines.
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Cleaning and sanitation are two different jobs, done in that order, and together they are the single biggest determinant of whether a batch turns out clean or infected. Cleaning removes visible soil — trub, hop matter, yeast, beer stone, oils. Sanitising reduces the microbes on an already-clean surface to a level that will not spoil beer. Sanitiser cannot work on a dirty surface: soil shields microbes and neutralises the sanitiser. Always clean first, then sanitise.
The 80 °C rule
Above roughly 80 °C, wort and the surfaces holding it are effectively self-sanitising. Below that, beer is vulnerable. The working rule for the whole cold side:
Once the wort drops below ~80 °C, anything that touches it must be sanitised first — chiller, tubing, taps, fermenter, lid, airlock, hydrometer, spoon, scissors, yeast pack, hands.
Most infections are introduced after the boil by an unsanitised item, usually late in a long brew day when attention slips. If you remember one thing, remember this.
The chemicals
| Product | Class | Job | Notes |
|---|---|---|---|
| Brewery wash / unscented dish soap | Detergent | Everyday removal of visible residue | Rinse thoroughly; avoid scented/anti-bac soaps that leave residue |
| Sodium percarbonate (PBW, Oxi-type) | Alkaline cleaner | Strips organic films, dried trub, beer stone, smells | Cleans, does not sanitise. Warm water boosts it. Rinse after |
| StarSan | Acid sanitiser (no-rinse) | Sanitises clean surfaces | Contact ~1–2 min; foam is fine; also passivates stainless |
| Campden (metabisulphite) | Water treatment | Neutralises chlorine/chloramine in brewing water | ½ crushed tablet per ~50 L; not a surface sanitiser |
Clean vs sanitise in one line: percarbonate and soap are cleaners (remove soil); StarSan is a sanitiser (kills microbes on a clean surface). They are not interchangeable.
Mixing and contact times
- StarSan — about 1.5 mL/L (1:640). It only needs to wet the surface for ~1–2 minutes to sanitise. No-rinse: drain and go; residual foam will not harm beer or yeast (“don’t fear the foam”). Mix with low-mineral water so it lasts; when it turns cloudy it is spent — remake it.
- Sodium percarbonate / PBW — follow the product dose (often ~1–2 tbsp per 4–5 L warm water for a soak). It is a soak-and-scrub cleaner, not instant — give it time to work, then rinse with clean water.
- Campden — crush and stir into brewing water; it neutralises chlorine and chloramine within a couple of minutes.
Per-stage routine
Hot side (kettle, mash, pump, recirc arm). These surfaces see far less contamination risk — everything is about to boil — but should still be clean. The key hot-side move is during the boil: recirculate boiling wort through the recirculation arm and out the lower tap so both transfer paths are sanitised before the cold side begins.
Cold side (chiller, fermenter, transfer gear). Everything below 80 °C must be cleaned then sanitised before contact:
- Clean: rinse → soap or percarbonate soak → rinse.
- Sanitise: StarSan, ~1–2 min contact, drain.
- Keep sanitised surfaces covered/closed until use.
The fermenter (the critical vessel):
- Cold-water rinse immediately after emptying — don’t let trub dry on.
- Brewery soap wash.
- Sodium percarbonate wash to strip organic film and smell.
- Rinse.
- StarSan sanitise just before filling.
Bottle and keg care
- Rinse every bottle the moment you finish drinking it. Dried-on dregs are the hardest soil to remove and the most common bottling headache. A bottle rinsed at drinking time needs only sanitising at packaging time.
- Stubborn residue — a sodium percarbonate soak lifts dried krausen rings and beer stone; rinse well afterwards.
- Kegs — disassemble posts and pull the diptubes periodically; percarbonate soak, rinse, then StarSan. Replace worn O-rings. Purge with CO₂ before filling.
Stainless care
Using StarSan as a final rinse helps passivate stainless — it builds the protective oxide layer and guards against pitting. Never leave chlorine bleach in contact with stainless; it causes pitting and rust. Dry everything thoroughly before storage so nothing sits damp.
Common mistakes
- Recurring infection / sour or gushing bottles — usually an unsanitised cold-side item, or scratched plastic harbouring microbes. Replace scratched plastic fermenters and tubing; tighten the cold-side routine.
- Sanitiser on a dirty surface — ineffective. Re-clean, then re-sanitise.
- Cleaner not rinsed — percarbonate/soap residue can hurt flavour and head retention; rinse before sanitising.
- Plaster / band-aid flavour (chlorophenols) — chlorine or chloramine in the brewing water, or bleach used to sanitise. Switch to campden-treated water and StarSan.
- Scented soap residue — leaves perfume and oils in the beer; use unscented brewery wash only.