Curing rack's divider twine attracts mold in humid climate

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Garden Gives Me Joy

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In the first image, you will see the inside of one of my curing rack attempts. I bought this veg rack cheaply at WalMart because it has wheels and can be positioned into one of many corners in the house. I used either 4-layer sheer material or double-layered bedsheet fabric to block out dust but allow air flow. BTW, I live in a highly humid tropical rainforest climate. I used twine to divide each level into rows to separate batches. The twine's package label suggested that it was nylon.

However, you will see in the following 2 images that mold grew wherever the soap contacted the twine. I thought this problem was possible only with cotton.

Suggestions, thoughts?
 

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Last edited:
Mold will grow wherever moisture collects. It's agnostic about the substrate. Organic materials will degrade under microbial attack much faster than synthetic, but ... anything that stays damp will host molds & mildew.
 
In the first image, you will see the inside of one of my curing rack attempts. I bought this veg rack cheaply at WalMart because it has wheels and can be positioned into one of many corners in the house. I used either 4-layer sheer material or double-layered bedsheet fabric to block out dust but allow air flow. BTW, I live in a highly humid tropical rainforest climate. I used twine to divide each level into rows to separate batches. The twine's package label suggested that it was nylon.

However, you will see in the following 2 images that mold grew wherever the soap contacted the twine. I thought this problem was possible only with cotton.

Suggestions, thoughts?
I use similar baskets; I'm not understanding why you're using twine to separate batches. I put a couple of paper towels down and set my soaps upright in rows and, as my husband says, "Bob's your uncle!". No twine required.

20220812_080221_HDR.jpg
 
Suggestions:

Toss out that very porous twine. Porous surfaces foster mold & mildew growth more than non-porous surfaces, so if you want to use something like twine, try fishing line instead or something less porous that the mold will have difficulty latching onto.

Use a de-humidifier in the soap curing room to pull excess moisture from the air. Keep in mind that you may have to empty a reservoir of water from said dehumidifier frequently in order for it to continue to reduce humidity.

Run a fan in the soap curing area to increase air movement in the room.

Get & use a hygrometer to monitor the humidity level in your soaping room and make adjustments to the environment as necessary. The EPA suggests that Relative Humidity below 60% is best for minimizing or preventing mold growth, so I'd start by trying to reduce humidity at least in the soap curing room.


Thoughts:

If you want to continue to use twine, soak it in a bleach solution and hang to thoroughly dry before re-using it, keeping in mind that periodic bleach soaking will be necessary. Bleach will will kill mold & mildew but will not prevent future growth.

Another adjunct solution could be to reduce the water in your soaps. By reducing liquid in your soap, you have less water evaporation in the curing room. If you are making soap with the default setting of Soapcalc (if you use that calcuator), your soap has a lot of water to start with. You can alter the recipe with a lower water to lye ratio (also known as a higher lye concentration) and still safely make soap, but the amount of water evaporating into the soap curing space is less, thus contributing less to the humidity level therein. Just another thought and one I would certainly consider reasonable.
 
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