Cleaning & Sanitation

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.

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 one unsanitised item, usually late in a long brew day when attention slips. If you remember one thing, remember this.

The chemicals

Clean vs sanitise in one line: percarbonate and soap are cleaners; StarSan is a sanitiser. They are not interchangeable.

Nothing chlorine-based, anywhere. Bleach, Milton and generic “steriliser” tablets are hypochlorite or NaDCC, and they are a direct route to the plaster and TCP fault. Sodium percarbonate is fine — that is oxygen bleach, no chlorine in it. Keep dishwasher powder away from bottles and glassware for the same reason.

Mixing and contact times

• StarSan — about 1.5 mL/L (1:640), needs only to wet the surface for 1–2 minutes. No-rinse: drain and go. Residual foam will not harm beer or yeast. Mix it with RO, distilled or campden-treated water — it lasts far longer that way, and mixing it with chlorinated tap water is a genuine fault route, since the acid does not neutralise chlorine and you are leaving the solution in contact on purpose. When it goes cloudy it is spent
• Sodium percarbonate / PBW — follow the product dose, roughly 1–2 tbsp per 4–5 L of warm water for a soak. It is a soak-and-scrub cleaner, not instant. Rinse afterwards
• Campden — crush and stir into brewing water; neutralises both chlorine and chloramine within a couple of minutes

Per-stage routine

Hot side (kettle, mash tun, pump, recirc arm). Lower risk, since everything is about to boil, but still keep it 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 gets cleaned then sanitised before contact:

1. Clean: rinse → soap or percarbonate soak → rinse
2. Sanitise: StarSan, 1–2 minutes contact, drain
3. Keep sanitised surfaces covered or closed until use

The fermenter, which is the critical vessel:

1. Cold-water rinse immediately after emptying — never let trub dry on
2. Brewery soap wash
3. Sodium percarbonate wash to strip organic film and smell
4. Rinse
5. StarSan just before filling

Shared kit, borrowed kit, group brew days

This is where a club differs from a brewer working alone, and it is where most of the club’s avoidable faults come from.

Nothing porous or scratched gets shared. Plastic fermenters, tubing, gaskets and bottling wands all hold microbes in scratches that cleaning does not reach. Stainless, glass and unscratched fittings are fine to lend; anything soft or scored is not. Tubing is cheap; a spoiled batch is not.

Wild and clean gear never mix. Brettanomyces and souring bacteria permanently colonise plastic. If you have done any wild or sour work, that kit is now dedicated to it — do not lend it out, and do not borrow anyone else’s without asking what has been through it.

Saison and Belgian yeast travels. Diastaticus strains come in ordinary commercial packets and bring over-attenuation and phenol together. If you or the person you borrowed from has brewed a Belgian, a saison or a wheat beer recently, pay particular attention to fermenter taps, scratched plastic and harvesting jars. Details in Bandaid, TCP & Clove.

Shared mills carry more than grain. Peated and smoked malt leaves guaiacol and cresols in the rollers, and in trace amounts — with none of the smoky context to explain it — that reads as medicinal TCP in the next brewer’s beer. If you mill smoked malt, run a kilo of base malt through afterwards and tell whoever is next.

On a group brew day, agree up front who is mixing sanitiser and what water it is being made with. One shared bucket made up with untreated tap water faults everyone’s batch at once rather than one person’s.

Buying in bulk is worth organising as a club. Percarbonate and StarSan both keep well unmixed, and the per-litre cost of StarSan concentrate drops sharply at size.

Bottle and keg care

• Rinse every bottle the moment you finish drinking it. Dried dregs are the hardest soil to shift and the most common bottling headache. A bottle rinsed at drinking time needs only sanitising at packaging time
• Stubborn residue — a percarbonate soak lifts dried krausen rings and beer stone
• Kegs — disassemble posts and pull the diptubes periodically; percarbonate soak, rinse, then StarSan. Replace worn O-rings. Purge with CO₂ before filling
• Before a competition, purge the fill line with CO₂ after sanitising and before the first bottle. Residue lands in the first bottles filled, which are usually the entries — see Kegging, Carbonation & Competition Bottles

Stainless care

StarSan as a final rinse helps passivate stainless, building the protective oxide layer and guarding against pitting. Never leave chlorine bleach in contact with stainless — it causes pitting and rust. Dry everything thoroughly before storage.

Common mistakes

• Recurring infection, sour or gushing bottles — usually an unsanitised cold-side item, or scratched plastic harbouring microbes. Replace scratched fermenters and tubing
• Sanitiser on a dirty surface — ineffective. Re-clean, then re-sanitise
• Cleaner not rinsed — percarbonate or soap residue hurts flavour and head retention
• Plaster or TCP flavour — chlorine in the brewing water, bleach used to sanitise, or sanitiser mixed with untreated tap water
• Scented soap residue — leaves perfume and oils in the beer; unscented brewery wash only

See also: Brewing Water Basics for treating the water in the first place, and Yeast Handling for harvesting hygiene.