SOP — Preparation of Chemical Baths; Caustic & Peracetic¶
FUERST WIACEK Version 1.0 | Production floor — all fittings
Purpose¶
The Caustic (Lauge) and PAA (Saure) 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 solution | Chemical burns, eye damage / blinding |
| PAA solution | Chemical burns, respiratory irritation |
| PAA soak exceeding 10 min | Gasket degradation and weld damage on fittings |
Preparing the Baths¶
- Confirm both baths are empty and visually clean. If not, rinse out with the spray gun before filling.
- Fill each bath to 50 L using the short blue hose connected to cold water at the panel. Do not use spray guns.
- Dose chemicals into their respective baths:
- Lauge bath (Caustic): 1 L
- Saure bath (PAA): 50 ml
- 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.
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 |