One of the nicest things about eating a traditional meal in a restaurant in India lies at the very end of the decadent, drawstring-loosening repast. Apart from the tiny bowls of areca nuts, fennel seeds, rock candy, and more that float out, I always wait in glee for the steaming bowl of hot water that comes with a sliver of lemon floating on its belly. I love to dunk my ghee-laden hands in the finger bowl (as we refer to it), letting the hot water splash and wet my fingers, scrubbing the lemon on my nails and palms till my skin is prune-like, clean, and faintly scented of citrus.

But it was only a few summers ago that I saw lemon’s potency as a cleanser. At a friend’s home, I saw huge plastic tubs stacked in the kitchen. After gorging on some oranges and drinking lemon water, he dunked their skins in the cavernous hold of the drums, adding to the floating cesspool of rotting peels, water, and jaggery. It was my first introduction to bio enzymes, an organic formulation of fermented fruits and vegetables in a sugar-water solution.

An effective cleaning product, bio enzyme is a concentrated solution. While the enzymes work by reacting on different soils and breaking them into smaller molecules, the bacteria consumes the smaller debris. This biodegradable solution is potent, effective, and environmentally friendly, and is easy to make and use, as we see ahead.

How to Start a Batch

he easiest and most fragrant way to start your journey is with citrus peels, taking a few months to ferment (depending on the recipe you follow). The first time always seems daunting, but once you begin, you can’t stop. I started making bio enzyme just before the pandemic struck, as a byproduct of my frenzied composting. Instead of composting citrus peels, I decided to make bio enzyme from them, using a standard recipe.

The recommended concoction is one part of jaggery, three parts of citrus peels, and ten parts of water, or 1:3:10. Jaggery is an unrefined sugar, also known as non-centrifugal sugar because it isn’t spun during the process of making. If you don’t have access to it, some recipes suggest using blackstrap molasses instead. Citrus peels can be lemon, orange, etc. Watch this video by urban farmer and waste management practitioner Vani Murthy to learn.

Add everything to a plastic bottle with a large mouth—avoid glass bottles as the gases released can cause it to explode—and let it ferment for around three months. (It can be two months or shorter if you add yeast or old bio enzyme to hasten the process.) I "burp" the bio enzyme bottle occasionally, and voilà, after 12 weeks, the super grime remover is ready. I prefer to compost the squishy peels, though you can grind them to get a super gooey, pulpy cleaner.

How to Use It

My favorite place to use it is in the bathroom, as well as for cleaning floors and surfaces. (Do a patch test to ensure it doesn’t stain.) For stubborn grot you can splash it undiluted, but for cleaning the sink and floors, dilute the concentrated cleaner before use. It’s a hard-working, albeit slow, workhorse. For stubborn stains you can leave the cleaner to sit overnight. I do try and splash or spray it at least half an hour before actual cleaning to dislodge any gritty dirt clinging to surfaces. You might not immediately fall in love with the fermented citrusy odor, but it grows on you over time.

Experiment With Your Bio Enzyme

Like composting, the challenge with bio enzyme is the problem of plenty, explaining the huge drums stored in my friend’s home. You start running out of bottles—but never out of bio enzyme! Most people date their bottles to remember when they fermented it, which is a good idea when you have a few dozen stashed under the sink. Once you’re a pro at the art of fermentation, you can experiment with the ingredients. Papaya or banana peels, pineapple skin, rotten stinky fruit and even shriveled marigold flowers strung during our colorful festivals have been successfully used by my acquaintances to create bio enzyme.

For something that’s bubbled in the darkness of a cupboard, bio enzyme is cheap to produce, wonderfully versatile to use as a cleaner, and, last but not least, comes with a whiff of cheerful citrusy freshness.