Probiotic Jamu Soda: A Modern Twist on a Traditional Herbal Tonic

Probiotic Jamu Soda: A Modern Twist on a Traditional Herbal Tonic

A traditional Jamu is typically prepared by boiling ingredients down to a decoction, consumed fresh or refrigerated for a short period. I've always been fascinated by food preservation through fermentation. This method offers compelling benefits, especially for turmeric, and I realized it could be key to increasing the bioabsorption of curcumin, turmeric's active compound, which is notoriously difficult for the body to absorb.

Fermentation breaks down turmeric's cell walls, allowing microbes to produce enzymes that transform curcumin into more bioavailable forms (metabolites). Some sources even suggest this process can increase curcumin concentration and solubility. The challenge for our human body to absorb curcumin is significant; even a little black pepper (piperine) helps, or consuming turmeric with a fat like coconut oil or ghee. Fermentation adds another powerful layer to this.

Wild fermentation also introduces beneficial bacteria and yeasts (probiotics) into the Jamu. These live cultures can support gut health, improve digestion, and potentially boost the immune system by modulating gut microbiota and producing beneficial compounds. Fermentation can even lead to the production of other bioactive compounds, like gamma-aminobutyric acid (GABA), known for its calming effects, contributing to holistic wellness.


Scientific References

 

Beyond the health benefits, fermentation naturally preserves food by creating an acidic environment that inhibits spoilage microorganisms. This means longer storage, even without immediate refrigeration, and significantly extended shelf life in the fridge – a huge plus for convenience!

And then there's the flavor. Fermentation adds a unique depth, with a pleasant tanginess and natural effervescence, making the Jamu a delightful drink. Surprisingly, it has smelling notes of sweet orange and flora, followed by a satisfying spice kick at the first swallow.

I want to share how you can make it too! Given Singapore's easy access to fresh turmeric, you can easily cultivate wild microbes by creating a turmeric 'bug'.

 

General Process for Wild Fermented Turmeric Jamu: Our Recipe at Amanita Ferment Station

Jamu is an integral part of Indonesian culture, with its recipes and preparation methods having been inherited across generations. This traditional Indonesian herbal medicine is crafted from a variety of natural ingredients, including roots, barks, flowers, seeds, leaves, and fruits. Widely consumed, often from street vendors or stalls, Jamu serves both preventive and curative health purposes. Its many recipes vary by region, personal preference, and specific health needs, but common components include turmeric, ginger, lime, honey, and tamarind

Here's a general outline of my craft. Remember, wild fermentation can be a bit experimental, so adjust ratios based on your environment and desired taste profile. You'll find a more detailed breakdown of each ingredient and step further down.

Ingredients:

  • Turmeric Root
  • Ginger Root
  • Lemongrass
  • Lemon
  • Tamarind preserves (with salt)
  • Water (non-chlorinated)
  • Natural sugars like honey, coconut sugar, or palm sugar
  • Black Pepper
  • Starter Culture (a "turmeric bug" or alternatives suggested below)
  • Optional Spices: Cinnamon, star anise, cloves, licorice root.
  • Optional Sweeteners: Red dates, or Medjool dates

Equipment:

  • Cold press juicer, blender, or grater
  • Large glass jar(s)
  • Tight weave cloth or breathable lid
  • Fine mesh strainer, coffee filter, or nut milk bag
  • Jars or bottles for finished Jamu (swing-top bottles are great for carbonation)

Steps:

  1. Prepare Ingredients: Wash and chop the lemongrass, turmeric, and ginger.
  2. Decoct into a Tea: Boil some of the prepared ingredients for at least 20 minutes to extract their beneficial compounds and flavors.

  3. Combine Ingredients: Mix the herbal tea (if used), freshly extracted juices, sugar, and other ingredients.
  4. Initial Fermentation: Pour the mixture into a clean glass jar, add starter culture (if using) once cooled, cover with a breathable lid, and place in a warm spot.
  5. Monitor Fermentation: Look for bubbles and taste daily for increasing tanginess and fizz.
  6. Strain: Once fermented to your liking (typically after 3 to 5 days), strain out the solids.
  7. Bottle & Secondary Fermentation (Optional): Transfer to airtight bottles, refrigerate, or allow for further carbonation at room temperature before refrigerating.
  8. Food Safety: Always trust your senses; discard if it smells or tastes off, or shows mold.

 

Diving Deeper into Our Jamu Craft

Now that you have the basic steps, let's talk details for optimal results:

Ingredients Deep Dive

Fresh Turmeric Root: The Star!

Use a generous amount of fresh turmeric root. You can leave the skin on after scrubbing well, as it contains nutritional compounds and beneficial yeasts good for the microbes. Some prefer to peel it to avoid any earthy taste or for what they consider a 'cleaner' and 'safer' process.

When working with turmeric root, I always remind myself to be extremely mindful and meticulous about the objects and equipment I use. Turmeric stains, and it stains powerfully! If you're using your blender, be prepared for a vibrant yellow hue. Even stainless steel surfaces and your hands will likely get tinted, though the stains generally fade over time. White countertops, however, can be particularly challenging and might even require abrasive cleaning like sandpaper for stubborn marks.

Turmeric's staining power comes from curcumin, the yellow pigment in the spice. Its ability to bind to various materials makes the stains difficult to remove, and you might notice your tools feeling a bit sticky after contact. For instance, a bamboo skewer stick is a lifesaver for getting into the crevices of blender parts to tackle those persistent turmeric stains.

For this recipe, turmeric is the trickier ingredient to handle, but its incredible herbal medicine properties definitely make it worth the effort!

Ginger Root
A classic Jamu complement with its own health benefits.


Lemongrass
Adds a nice aroma to your Jamu and can also provide calming benefits.


Lemon
A squeeze of lemon or lime juice, are traditional Jamu additions that also help lower the pH, making it more favorable for beneficial microbes.

Beyond the juice, I frequently incorporate lemon peels into my decoctions for their limonene and polyphenols, which offer significant therapeutic benefits. Lemon peel isn't widely used in traditional processing, often discarded as food waste despite its thick, rough texture. While a small amount features in some traditional Chinese medicine, and culinary kitchens value lemon zest for adding flavor depth to salad dressings or dessert creams, it's worth noting that in food science, lemon flavors come mostly from the skins, not their juice. It's quite a pity most of us toss them in the bin!

At our kitchen, I either zest them to infuse in extra virgin olive oil for garnish or salad dressing, or I preserve them in white vinegar. After months, you can extract their citrus oils (limonene), which gives them their citrus aroma. You can then dilute this for cleaning purposes. It's one of many zero-waste, efficient ways to use your lemon peels and a non-toxic living solution. At our kitchen, we use a lot of citrus for their nutrition and ferments.

 

Tamarind preserves (with salt)
This ingredient is readily available in Asian markets, larger supermarkets, and even general grocery stores across Singapore. It's a staple in many cuisines, from Assam to various curries. In traditional Indonesian Jamu, tamarind is a core component. It's highly regarded for its digestive benefits and its ability to soothe stomach discomfort. When incorporated into Jamu, often alongside turmeric and ginger, it forms a powerful combination traditionally believed to offer anti-inflammatory, antioxidant, and blood-purifying effects.

 

Water
Use non-chlorinated water (reverse osmosis or spring water is best). Since most filters don't entirely remove chlorine, I'd still boil filtered water first, as chlorine dissipates with evaporation. In our recipe, a herbal decoction is used instead of directly adding water to infuse and ferment with the spices.

 

Sugar (for fermentation)
Any natural sugars work, such as honey, coconut sugar, or palm sugar. The microbes will consume most of this, reducing the final sugar content. Start with a moderate amount, aiming for at least 5 to 8% sugar by weight.

In case you are wondering, Stevia is not a sugar; it's a sugar substitute derived from the Stevia rebaudiana plant, unlike sugar extracted from sugarcane or beets. If you're concerned about sugar levels, remember most of the sugars will be digested by the bacteria and yeasts, as sugar is one of the main foods for microbes. Also, raw sugars contain many minerals. When purchased and consumed in the right amounts, they can be beneficial for our bodies. Sugar is often frowned upon because commercial products use processed sugars, where minerals are stripped and all nutritional benefits are lost.

You can also add spices for natural sweetness and additional nutrition. I use cinnamon in this recipe. Other suggestions include:

  • Star anise (known for its licorice flavor, and contains shikimic acid, a main antiviral compound extracted and used in the popular Tamiflu influenza drug).
  • Cloves
  • Licorice root
  • Red dates or Medjool dates
  • Black Pepper: Crucial for curcumin absorption. While fermentation aids bioavailability, piperine in black pepper still significantly enhances it.

Starter Culture (recommended for consistency): While "wild" fermentation relies on naturally occurring microbes, a small amount of a known starter can provide more consistent results. I use a "turmeric bug," a fermented starter made from turmeric, sugar, and water, cultivated over time.

Alternatives include a splash of active, unflavored kombucha, tepache, whey from yogurt or kefir, or even a tiny piece of unpasteurized sauerkraut or kimchi (though this might impact flavor). Aim to add around 10% starter culture into your brew to kickstart the fermentation.

Steps Deep Dive

1. Prepare Ingredients

Wash and chop the lemongrass, turmeric, and ginger. I use a cold press juicer to extract the juice to be added into the recipe and use the pulp to boil into a tea, so nothing goes to waste, in the spirit of zero-waste produce utilization. 


The filtered pulp then goes into my compost bin. If you do not have a cold press machine, another way is to grate them finely or blend with some of the water to create a pulp and boil them to decoct.


2. Decoct into a Tea 

Depending on the flavor profile you want, you can decoct as you wish. For me, because I am already adding more of the cold-pressed turmeric juice in my recipe, I decided to decoct only the lemongrass and ginger into a tea, with added lemon peels (for their limonene and polyphenols, which offer significant therapeutic benefits) and cinnamon (antiviral, improves insulin sensitivity, antimicrobial – the chemical compound in cinnamon, cinnamaldehyde, has shown antibacterial and antifungal effects, helping protect against infections and slow down the growth of some bacteria and fungi). 

One thing's for sure: your home will smell lovely with the herbal aroma, especially from the oils of the lemongrass, which are both citrusy and floral.


3. Combine herbal tea with sugar and mix until sugar dissolves.


4. Initial Fermentation

Pour the mixture into your clean glass jar, leaving a few inches of headspace. 

If using a starter culture, add it only once the tea has cooled and stir in gently, mixing in the microbes. If the tea is too warm, you risk destroying the beneficial microbes. Cover the jar with cheesecloth secured with a rubber band, allowing air exchange. This prevents contamination while allowing fermentation gases to escape while providing an aerobic environment where yeast utilizes oxygen to metabolize sugars during fermentation, producing ethanol and carbon dioxide as a byproduct. 

Place the jar in a warm spot (ideally around 21−28°C) out of direct sunlight. Singapore's climate is generally well-suited for this. Note that if your environment is cooler, such as an air-conditioned place, fermentation would take longer.

5. Monitor Fermentation

  • Bubbles (CO2 byproduct): Within 1-3 days (or longer, depending on your recipe, amount of starter culture and sugar used, temperature, and environment), you should start to see small bubbles rising to the surface, indicating active fermentation.
  • Stir, Smell & Taste: Stir the ferment and taste a small amount daily. It should become increasingly tangy and slightly fizzy. 

6. Straining

Once fermented to your liking, strain out the solids using a fine-mesh sieve or coffee filter.


7. Bottling & Secondary Fermentation (Optional)

Transfer the liquid to airtight bottles (swing-top bottles are ideal) and refrigerate. If you want more carbonation, you can leave them at room temperature for another 1-2 days. 

Note: at room temperature, the microbes would still be fermenting, and it may become more acidic as the days pass. Be mindful of "bottle bombs" due to pressure buildup; burp the bottles periodically if unsure.

8. Food Safety

Always trust your senses. If it smells off, looks moldy on the surface, or tastes unpleasant, discard it. As a general rule of thumb for fermentation, sanitize all your equipment – either through heat (like boiling or oven bake) or using an equipment sanitizer (if you're a seasoned fermenter). Most importantly, ensure everything is completely dry before you use it to prevent unwanted contamination

My approach respects Jamu's traditional roots but also elevates its health benefits and practicality for modern living.

A wild-fermented turmeric tonic for enhanced goodness, meticulously crafted with lemongrass, warming ginger, cinnamon, tamarind preserves, bright lemon & black pepper.

Unpasteurized & naturally rich in live cultures. A raw, living product. Naturally potent. A natural powerhouse to help build immunity.

Important note: This recipe is intended to naturally ferment herbs and spices with sugar and may contain trace amounts of ethanol due to lactic acid bacteria. Those sensitive to ethanol, pregnant, nursing, or with dietary restrictions should consult a healthcare professional before consuming. It is unpasteurized and contains live cultures that may aid digestion but might not be suitable for individuals with compromised immune systems. Consult your physician if you have any concerns.


Inspired to try fermented Jamu? If you're not ready to brew your own just yet, you're in luck! Our probiotic Jamu soda is now available on our e-store, and it's here to stay.

Want to cultivate your own wild microbes? Sign up for our mailing list to get updates on our public fermentation workshops—let's learn together!



Disclaimer

I am an herbalist, not a licensed medical professional. The information shared here is for educational purposes only and is intended to support your general health and wellness. It is not a substitute for medical advice, diagnosis, or treatment.

Please consult your primary healthcare provider before using any herbs or supplements, especially if you are pregnant, breastfeeding, trying to conceive, taking medication, or have a pre-existing health condition. Herbs can cause individual sensitivities, side effects, or interact with medications; therefore, it is essential to consult a qualified healthcare practitioner or a trained herbal professional before starting any new regimen.

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