Skip to content

SOP — Preparation of Chemical Baths; Caustic & Peracetic

FUERST WIACEK Version 1.3 | Utilities — small parts and fittings sanitation | Frequency: prepared weekly, used continuously


Purpose

The Caustic (IC 1002) and PAA (DI 1011) baths are used to clean and sanitise fittings and small parts between production uses. Any item that has come into contact with wort, beer, or organic solution must pass through both baths before returning to service. Gaskets must be removed prior to soaking and placed alongside the equipment. Small parts and gaskets should be placed in the blue containers provided and submerged in the bath — ensure all parts are fully covered by the chemical and are not floating on the surface or sitting above the liquid level.


PPE Required

Warning

Do not approach the baths without:

  • Safety goggles
  • Chemical-resistant gloves

Risks

Hazard Risk
Caustic (IC 1002) Chemical burns, eye damage / blinding
PAA (DI 1011) Chemical burns, respiratory irritation
PAA soak exceeding 10 min Gasket degradation and weld damage on fittings

Preparing the Baths

  1. Confirm both baths are empty and visually clean. If not, rinse out with the spray gun before filling.
  2. Fill each bath to 50 L using the short blue hose connected to cold water at the panel. Do not use spray guns.
  3. Dose chemicals into their respective baths:
    • Lauge bath (Caustic / IC 1002): 1 L
    • Saure bath (PAA / DI 1011): 50 ml
  4. Rinse dosing containers and return to storage.

Using the Baths During Production

Step Bath Duration Notes
1 Caustic (Lauge) 15–20 min After any contact with wort, beer, or organic solution
2 Rinse fitting Before transferring to PAA
3 PAA (Saure) 5–10 min Do not exceed 10 min — risk of gasket and weld degradation

Fittings already clean and shelf-stored: soak directly in PAA for a short burst immediately before use.


End-of-Use Parts Storage — Universal Standard

After any production use — kegger line, canning line, wortway, brewhouse, yeast harvest, micro sampling, or any other operation involving fittings and small parts — all parts follow the same sequence before they are put away.

After use:

  1. Remove all seals and O-rings from fittings before placing anything in the bath.
  2. Place seals in the blue container — submerge in the caustic bath.
  3. Place all other parts in the caustic bath. Ensure everything is fully submerged.
  4. DN25 and DN40 hoses do not go in the bath — rinse with water and store separately.

Next day:

  1. Rinse all parts and seals with water.
  2. Transfer to the PAA bath. Parts remain in PAA until next use.

Note

Parts already clean and shelf-stored can skip the caustic step — dip directly in PAA for a short burst immediately before use.


Bath Maintenance

  • Baths are typically good for a full production week.
  • If physically soiled: drain, clean, and restart — do not attempt to correct with additional chemical.
  • Concentration can be validated periodically if needed (optional):
    • PAA → PAA test strips

Pre-Use Checklist

  • [ ] Lauge bath: clean and empty
  • [ ] Saure bath: clean and empty
  • [ ] Cold water tank pump on — 50 L in each bath
  • [ ] Caustic dosed — 1 L into Lauge bath
  • [ ] PAA dosed — 50 ml into Saure bath
  • [ ] PPE on before handling chemicals

Troubleshooting

Issue Likely Cause Action
Bath visibly cloudy or soiled Organic load too high Drain, clean bath, restart
PAA strips showing low concentration Bath exhausted or over-diluted Drain and re-dose
Gasket showing degradation PAA soak exceeded 10 min Replace gasket; retrain on soak times
Fitting still soiled after caustic soak Heavy soil load or insufficient soak time Manual pre-rinse, repeat caustic soak