After having been brewing for a couple years, my stainless steel pot no longer had that nice shine it first had when I bought it. It was time to do a ‘deep’ clean and re-passivate the stainless steel.
Doing searches on the web showed results that talk about using nitric acid to passive the stainless. However this is not an easy acid to obtain. The next option suggested was Star San in a higher concentration. Although it may have passivated the stainless, it still did not restore the prior shine I was looking for in my stainless steel equipment. Searching further, I found suggestions of using BS removing from Five Star. This however did not help, and a puddle accidentally left to dry in the pot led to a rust area that would not come out, even with the use of more BS remover.
Searching further finally led me to Bar Keeper’s Friend (BKF). BKF is an oxalic acid cleaner and when using it I was able to successfully lift the tarnish, remove the rust, and re-passivate the stainless steel.
Caution: Test out BKF on a small trial spot before applying to the entire affected area to ensure you are okay with the reaction BKF will have with the metal surface.
Here is the process I followed:
- Wet the surface of the stainless to be passivated with tap water.
- Sprinkle on BKF until the surface is covered in a fine layer.
- Add additional water and/or BKF as needed to form a wet paste.
- Using a sponge, or other non-abrasive fabric, gently wipe back and forth along the grain of the steel. This is important as BKF by itself is slightly abrasive and will put really fine lines in the stainless that stand out if the wiping motion is against the grain. If the stainless steel is polished, do not wipe at all, instead just let the paste sit on the stainless steel for 5 minutes.
- Thoroughly rinse out the area where BKF was applied. Inspect and repeat steps 1 thru 5 if there is more tarnish and rust that needs to be lifted.
- Once satisfied, towel dry the area exposed to BKF.
- Let the pot sit for a couple days with nothing in it and exposed to the air to fully passivate the stainless surface.
The stainless should now look good as new!
