Introduction: Electrolytic Acid Etching Aluminum Brew Kettle


Brew kettle

1/4 cup White vinegar

1/4 tsp Salt

Fresh 9-volt battery

Electrical wire (speaker wire worked for me)

Electrical tape or other masking medium



1. Measure out exactly one gallon of water and pour into your kettle. Mark the 1 gallon mark with a temporary marker such as electrical tape. Continue pouring in 1 gallon at a time and marking each spot until you have reached capacity. In my case, the kettle goes up to 7 gallons (for you water conscious individuals perhaps you can use the leftover water to add to your fish tank, water the plants around the house or pour it into your washing machine for the next load of laundry instead of just pouring it down the sink).

2. replace temporary markers with stickers, stencils or whatever you see fit to use. I used my own desired font and size and made stickers out of them. I suggest using ultra-sticky stock for this option. Perhaps if I were to do it again I would use something that was easier to remove once the etching was complete.

Step 1: Etching the Kettle

3. Combine the 1/4 cup of vinegar (any should work but I used white) and your 1/4 tsp of salt (completely dissolved).

4. Attach your 9V battery to the kettle (+positive lead).

5. Strip the end of the negative wire and tightly twist-tie it around the end of your q-tip. Attach the other end to the negative side. I used electrical tape and a fat rubber band to help make the connections.

6. Safety Tip: DO NOT INHALE THE FUMES FROM ETCHING. I have read they are very carcinogenic. I could be wrong, but it's not worth the risk so DON'T breathe the smoke that comes from the reaction. Etching in a well ventilated area is strongly recommended.

Dip the q-tip into the vinegar solution, take a deep breath, let it out, relax, and be patient. This will take a little time. Dab the tip of the q-tip where you want to etch. If everything is connected properly and your battery has a good charge, you should see some bubbling coming from the wire portion attached to the q-tip as well as a faint wisp of smoke (that is purportedly VERY bad for you!). After going over each number three or four times I still felt like it wasn't etching very well so I left the kettle out overnight and didn't rinse it until morning. I was very pleased with the final result.

Step 2: The Finished Product

Here is the finished job. Never mind the browned portion at the bottom. That was from a previous brew that darkened the metal.

Edit: After brewing a batch of beer I plan on adding half-gallon marks and suggest it to all you brewmasters out there.

Step 3: The Etched Kettle in Action

Here's a picture of the newly-etched kettle in action.


tomatoskins (author)2015-07-03

Great instructable! Does this only work with aluminum?

kurtck (author)tomatoskins2015-07-03

I believe it also works on stainless steel but I haven't tried it myself. Here is the fantastic article from Brew Your Own I referenced to accomplish this:

PocketBrain (author)kurtck2016-09-02

I did this to a stainless steel thermal vacuum tumbler cup. I only needed salt water, though. It might take longer, but it works!

Tomahawk92 (author)tomatoskins2015-07-03

I've done it to steel.

BadAngelZ (author)2015-07-03

I should not recommend brewing in an aluminum kettle, or if you do so never use stainless steel tools to stir (in fact don't use any other metal, but stainless steel is particularly a bad choice). Else this will make a battery when brewing.

You will not notice the color change during brewing, but try this experience: put some dish-washing liquid (like if you want to wash your kettle), lots of water and proceed like if you were brewing: warm the water while steering. After 30 minutes, have a look at the water color: it will be gray ! and your kettle will be thicker inside (something like 0.2mm).

I experienced this trying to make an automated stirring and brewing system using an aluminum kettle, an aluminum stirrer and some (few) stainless steel nuts and bolts. When I finished assembling all the stuff, I tried to wash it in the way I described above, and understand later why I got grayed water ...

Here are some videos of the experiment:

So if you don't want to drink alumina flavored beer, please consider not mixing metals. I should recommend to use stainless steel kettle and stirring tools as this does not costs a lot (I got a 35 liters kettle for 50 € shipping costs included on ebay...).

Habby brewery !

Victor Does (author)2015-07-03

Great work! Will try this to my brewing kettles when I have some spare time!

About This Instructable




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