How to Clean, Sanitize, and Passivate Your Fermenter (Before First Use)

Getting a brand-new fermenter feels great — especially if it’s stainless steel. But before you pitch your first batch of yeast, there's one essential step many brewers overlook: prepping the fermenter correctly. Here's how to make sure it's clean, safe, and ready to deliver amazing results from batch #1.

🧼 Step 1: Cleaning – Remove Manufacturing Residues

Even if your fermenter looks spotless out of the box, it likely has machining oils, dust, or polishing compounds from production.

What to use:

• Chemipro Wash, PBW, or another brewery-safe alkaline cleaner
• Optionally: TSP (trisodium phosphate) for aggressive cleaning of heavy residues

How to clean:

• Fill the fermenter with warm water and add cleaner as per dosage
• Let it soak 15–30 minutes, especially around fittings and joints
• Scrub gently with a soft sponge or cloth (never steel wool)
• Rinse thoroughly with warm water

💡 Pro tip: Don’t forget to clean all fittings, gaskets, valves, and accessories — anything that touches your wort.

🧪 Step 2: Passivation – Protect the Stainless Surface

Stainless steel forms a passive chromium oxide layer that protects it from corrosion — but this layer can be compromised during manufacturing or deep cleaning. Proper passivation helps rebuild it.

Why it matters:

• Prevents long-term corrosion
• Ensures neutral flavor and protects your beer
• Increases resistance to chemical cleaners over time

Two recommended methods:

1. Citric Acid Passivation

• Mix a 3–5% citric acid solution with hot water
• Fill or spray the interior surfaces of the fermenter
• Let sit for 30–60 minutes
• Drain and rinse with clean water
• Allow to air dry completely (do not towel dry)

Citric acid is safer and easier to handle than nitric acid and is widely used in breweries.

2. Star San (Low pH Passivation)

• While Star San is primarily a sanitizer, its low pH (~3) can passivate stainless if left in contact for long periods
• Spray or fill the fermenter and allow contact for at least 10–20 minutes
• Drain and let air dry

🧽 Step 3: Sanitizing – Right Before Use

Cleaning removes dirt. Sanitizing kills invisible microbes. Always sanitize your fermenter before transferring chilled wort.

What to use:

• Chemipro San, Star San, or other no-rinse acid sanitizer

How to sanitize:

• Spray or fill with diluted sanitizer (follow instructions!)
• Let stand for contact time (usually 1–2 minutes)
• Drain and use — don’t rinse it off

✔️ Stainless fermenters like our PF Series make this easy: they’re fully weldless, smooth, and designed for fast CIP (clean-in-place) routines.

🔧 BrewTaurus Tips

• First use? Clean and passivate.
• Every use? Clean and sanitize.
• Store it dry and open when not in use.

You’re working with pro-grade equipment — treat it right and it’ll reward you with clean, consistent beer for years.

📣 Ready to Brew?

Our PF Series fermenters are built from 304 stainless steel, pressure-capable up to 2 bar, and easy to clean and sanitize.

📚 More Brewing Tips:

• How Pressure Fermentation Works
• How to Choose the Right Fermenter
• Why Controlled Fermentation Makes Better Beer

– Dan, Founder, BrewTaurus