I never passivated my Robobrew 35l 3.0 because nothing was mentioned in the instructions or any of the “first use” videos I watched on youtube, but it wouldn’t hurt to do it.
I passivated my Ss Brew Buckets as per the instructions :
First Time Cleaning
Pre-Clean: Prior to first-time use, thoroughly wash all surfaces of the vessel, including all valves and
fittings, with Tri-Sodium Phosphate (TSP) in hot water, mixed with the manufacturer’s
recommendations. Scrub with a soft terry cloth, and after the initial TSP wash, rinse thoroughly and
dry all surfaces.
Passivation: It’s good practice to periodically passivate all stainless-steel equipment with an acid
based solution to establish a uniform passive oxide layer that will maximize corrosion resistance.
Following the pre-clean step, fill the vessel with Star San at a concentration of 1 ounce per gallon at
70-80°F for 30 minutes. Moving forward, for best stainless performance, passivation should be
performed at least once a year or anytime you believe you may have inadvertently scratched the
surface.
Cleaning and Sanitizing: As part of a regular cleaning regimen both pre and post-fermentation,
wash the interior surfaces of your vessel with an alkali cleaner such as PBW at a ratio of 0.75 ounce
per gallon. Then sanitize with Star San or another acid-based sanitizer per the manufacturer’s
recommendations.
You can get TSP from Bunnings sold as Tricleanium. You don’t need to use 65l of starsan you dilute it at 1 ounce per gallon or 29.5ml to 3.785 litres so for your Brewzilla I figure you’ll need about 506ml of starsan to the 65 litres.
Maybe use Stellarsan from kegland or another cheaper alternative to Starsan.