How I Rescued a Moisture-Damaged Old Book Using Only Kitchen Pantry Supplies

Last winter, my heart raced when I discovered a 1940s short story collection in the back room of an antique shop in San Telmo. The cream-coloured cloth of the cover was steeped in age, and on the endpaper, someone's pencilled notes remained faintly visible. But the moment I opened the book, I could tell. The edges of the pages were warped in undulating waves, and brown stains had spread here and there. It was a book that hadn't survived the humid summers of Buenos Aires.

I brought it home for less than 2,000 pesos, but what it took to revive this book wasn't money. It was time and patience. Today I'm putting together the methods I've learned over decades of working in libraries and personally collecting secondhand books. No professional restoration equipment needed, just what you already have at home.

First, read the condition of the book

Before laying a hand on restoration, you need time to spread the book open and examine it slowly. I usually lay a clean cotton dish towel on the kitchen table and place the book on top of it. Here's what to check for.

• Are pages stuck together
• Are there brown spots known as foxing
• Is there a musty smell
• Is the binding thread or adhesive damaged

Forcing stuck pages apart will tear them. If mould is actively spreading (when you can see fuzzy mycelium on the surface) you need to dry and disinfect the book before attempting restoration. What this article covers is moisture damage that is already inactive, meaning cases where the book absorbed water in the past, dried out, and was left deformed.

Drying and odour removal

If you have a Buenos Aires apartment, you almost certainly have sodium bicarbonate (bicarbonato de sodio) in the kitchen. This is the key ingredient.

Prepare a large airtight plastic container. I use the big tupperware I keep empanada dough in. Spread an even layer of sodium bicarbonate on the bottom of the container, then place a mesh rack or small shelf on top so the book doesn't come into direct contact with the powder. I use an oven cookie cooling rack, which fits perfectly. Stand the book on the rack and close the lid.

Leave it like this for 48 to 72 hours. The sodium bicarbonate absorbs moisture and odour. The first time I tried this method was with a poetry collection I'd picked up in old Palermo, and I was amazed when I took it out. The old basement smell had almost entirely disappeared.

Flattening warped pages

To flatten pages that have warped into wavy shapes, you need weight and humidity control at the same time.

First, insert a sheet of regular copy paper between each of the most severely warped pages. The copy paper acts as a buffer while evenly dispersing any remaining moisture. Then close the book and place something heavy on top. I use a cast-iron grill pan (plancha de hierro) from the kitchen. If you have a Buenos Aires home, you're bound to have at least one cast-iron tool for asado. If you don't have a cast-iron pan, stacking several thick ceramic plates works too.

Distributing the weight evenly is the key. If the load is concentrated on just one side of the book, the binding will warp. I first place a wooden cutting board on top of the book to widen the surface area, then set the cast-iron pan on top of that.

Leave it like this for one week. On the third day, replace the inserted copy paper with fresh sheets. The copy paper may have become damp from absorbing moisture.

Reducing stains

Completely removing foxing stains falls within the domain of professional restorers, but you can make them less noticeable. I use 10-volume hydrogen peroxide (agua oxigenada). It's the same kind you can easily find at any pharmacy, the one used for disinfecting wounds.

Dab a very small amount of hydrogen peroxide onto a cotton swab and gently pat just the stained area. Rubbing will damage the paper fibres, so be sure to use a light dabbing motion. If it doesn't work the first time, wait for it to dry and repeat. Usually two or three applications will lighten the stain considerably.

One important note: never do this over printed text. Hydrogen peroxide can bleach the ink. It's only safe to apply on margins or areas without text.

That 1940s short story collection from San Telmo went through this entire process. It didn't become a perfectly new book. But once the pages were flat again, the smell was gone, and the stains had faded, even the pencilled notes inside became much clearer to read. "Hermoso final," someone had written in the corner of the last page. A beautiful ending. It must have been their impression of the book, but it was a phrase that perfectly matched how I felt after finishing the restoration.