Home Cleaning Tips Remove Stubborn Mildew and Mold Stains from Grout

Remove Stubborn Mildew and Mold Stains from Grout

by Catherine

So, I realize that I have written a previous post about this subject, but I thought it was worth addressing again, for when those stains are STUBBORN–as in, all caps indelible.

My kids and I are gypsies right now, staying with family members here and there, wherever anyone will take us in. Our home in Tennessee needs a LOT of work right now, and we are unable to live there until a good portion of the work has been completed. Moving around constantly is definitely not ideal with two children, but I do have to say, I’m enjoying living light, seeing and loving up lots of different family members and relatives, and really, really making some great memories with my kids.

Another “up” side to our travels has been my ability to assist various family members along-the-way with their mold cleaning dilemmas. As I wrote in my previous article about my sister’s home, it seems, so far anyway, that every home I stay in has a small mold-specific cleaning problem that needs my help. That is why this particular project presented itself.

Right now, I’m in Atlanta at my parent’s house. One day, while bending down to pick up food my kids had dropped on the kitchen floor, I happened to notice that my Mom needed her grout cleaned. From my crouched position, I noticed that she had quite the mold stain going on under her counter lip, where the grout line is hidden and connects the counter to the sink. I don’t know the exact term for that area, but it is notorious for trapping moisture and dish soap residue. That winning combination can produce mold, if you don’t clean it properly or dry it thoroughly after use. This area isn’t a place where you normally look or can see just standing in your kitchen, so it is often neglected and can get pretty bad before you realize that it needs cleaning. Many times, people notice a musty smell around their sink, and further investigation is what finally helps them discover what is causing it. Thus, stains in this area can be quite a bit more stubborn and tricky to remove.

Mold-stained grout line in my parent's kitchen sink.

Mold-stained grout line in my parent’s kitchen sink. It is begging to be cleaned.

Well, for this, the same rules apply, as in my post on Non-Toxic Solutions for Cleaning Tile and Grout for Mold. The only difference here is that her grout turned out to be significantly stained by the mold. In other words, it had been there for some time and wasn’t coming out without a fight.

We started the process much like I started the process for my grout in my shower, cleaning the area first with castile soap, warm water and a stiff old toothbrush to get it nice and clean.

Dr. Bonner's is my favorite kind of Castile soap to use for all applications in our home.

Dr. Bronner’s is my favorite kind of liquid castile soap to use for all cleaning applications in our home. It is made with organic ingredients, and does not cause my family any allergic reactions. We also love the scent options.

Then we went straight to applying the baking soda paste to the grout line, because we knew we needed something abrasive the give the grout a more manual, course cleaning. (Grout is a porous material and really absorbs and “breathes” in whatever is on it. Abrasive cleansers tend to work well to get it clean. Baking soda paste can be easily and quickly made by mixing just enough distilled water with baking to form a paste.) We even used the old toothbrush and really scrubbed the paste into the grout to remove whatever surface mold we could.

Baking soda paste is applied to the freshly cleaned grout line. Then, it will be scrubbed for a manual cleaning prior to the anti-mold rinse.

Baking soda paste is applied to the freshly cleaned grout line. Then, it will be scrubbed with an old toothbrush for a manual cleaning prior to the anti-mold rinse.

Then, since my Mom has many of the EC3 products, we measured out some EC3 Mold Solution Concentrate and mixed it with distilled water per package instructions, and put it into a spray bottle. (She did not have any of the ready-to-use EC3 Spray, which is already measured for you, or we would’ve used it, and made our lives that much easier.  Then, we sprayed the grout with it to both rinse the baking soda paste away and to further kill the mold at the root. Because my Mom and I are both chemically sensitive, using bleach in any form wasn’t going to be an option with this job.

Our first mold "rinse" consisted of the EC3 Mold Solution Concentrate mixed with distilled water, per bottle instructions.

Our first mold “rinse” consisted of the EC3 Mold Solution Concentrate mixed with distilled water, per bottle instructions.

A quick note on bleach for those curious as to why this chemical cleaner that both whitens and kills bacteria can also be bad for health: Mixing bleach with ammonia, vinegar or other acids, and even organic matter can cause dangerous chemical reactions that emit toxic and potentially carcinogenic fumes. When cleaning mold, aren’t we cleaning organic matter? Also, it is corrosive and can irritate the eyes, skin and respiratory tract—not something I want to mess around with. Enough of my informational sidebar…

After our first rinse was complete, we still had a pretty good mold stain remaining. As you can see…

The first rinse with the EC3 spray after the manual cleaning started to remove the mold--you can see it rinsing away. BUT, there was still a significant stain.

The first rinse with the EC3 spray after the manual cleaning started to remove the mold–you can see it rinsing away. BUT, there was still a significant stain.

While my Mom mixed us some more baking soda paste, I wracked my brain for a non-bleach solution to our problem. We were killing the mold effectively, but we weren’t fully removing the stain. I don’t have my handheld steamer in which to add the EC3 Laundry Additive at her home, so that wasn’t an option, like it is at my house. That’s also what I wrote about in my previous article on grout cleaning. Then, I thought of a mold-killing, grout lightener, which would also not react with the EC3 when added: hydrogen peroxide!

hydrogen peroxideA 3% solution of straight hydrogen peroxide has enough oxidizing power to kill mold on porous surfaces and to lighten any stains it has made. Also, unlike bleach, it doesn’t produce any harmful, volatile organic compounds (VOCs) when used for killing mold or bacteria. I couldn’t believe I hadn’t thought of it sooner! When we added 2 tablespoons of hydrogen peroxide to our EC3 spray solution, we immediately noticed the mold stain fading.

We continued spraying, scrubbing and rinsing, until only a slight stain remained.

After our first rinse with the hydrogen peroxide the stain was significantly lighter, but still not gone.

After our first rinse with the hydrogen peroxide added to the EC3 spray, the stain was significantly lighter, but still not gone.

Then, we increased the potency of the solution by adding another 1/4 cup of peroxide  to our bottle and fully saturated the stain with the solution, and let it sit for 1 hour.

After letting the more potent EC3/peroxide solution sit there for an hour, the stain had almost totally disappeared.

After letting the more potent EC3/peroxide solution sit there for an hour, the stain had almost totally disappeared.

When we returned, we sprayed again, scrubbed off what was left and finally had clean, sparkling white grout again.

The grout is finally white again!

The grout is finally white again!

It was definitely a process, but we did it. And, we were able to do it without the use of chlorine bleach. EC3 and peroxide for the win!

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