Sweet Fermented Purple Rice – Black rice tapai

This fermented purple rice is one of the rice-base Tapai variations, with black rice. In case you haven’t heard of the word,

Tapai or Tape/Tapay is a traditional Southeast Asian sweet fermented starch made from steamed glutinous rice or cassava. This beloved Asian fermented rice got its sweetness and slightly acidic flavor from the starch being broken down into sugar and alcohol.

That happens during fermentation over two nights with local yeast specifically for fermenting rice called ‘Ragi Tapai’.

If you are looking for a wholesome and gluten-free treat that is nutritious, you’ll love this sweet fermented purple rice. It is rich in antioxidants and contains beneficial microorganisms that can be a source of probiotics.

Table of Contents

• There are 2 variations of rice-base Tapai.
• What is black rice?
• Why is it called purple rice?
• How fermenting black rice may contribute to our health?
• Ingredients to make Fermented Purple Rice
• How to make Fermented Purple Rice
• How to know if the fermented rice is a success?
• Troubleshooting: How to know if the fermented purple rice is inedible?
• Common mistakes when handling Tapai
• Important Tips When Making Successful Tapai – Fermented Rice
• FAQ

There are 2 variations of rice-base Tapai.

1. Purple Rice Tapai/Black Rice Tapai—Also known as Tapai Pulut Hitam in Malay and Tape Ketan Hitam in Indonesian. It is made with 2 types of glutinous rice.
2. White Rice Tapai—A more common type of fermented rice made with 100% white glutinous rice.

Though not as famous as the white version, fermented purple rice is a healthier alternative to white glutinous rice. The main ingredient, which is black rice, is not only lower in sugar content but can benefits our health in many ways.

What is black rice?

Widely produced in Asian countries like China, Indonesia, Vietnam, and India, black rice is a whole grain that falls in a glutinous rice family. Black rice is more starchy and sticky than regular rice. Like most glutinous rice, black rice is not everyday rice as it is not grown as much as white rice.

Black rice is rich in amino acids and antioxidants (anthocyanins). This plant compound is known for its strong anti-inflammatory effects on our health, which may help protect us from diabetes, cancer, heart disease, high blood pressure, and many more oxidative diseases.

A 1/2 cup (90 grams) of uncooked black rice provide: (USDA)

• Calories: 320
• Fat: 3.0 grams
• Protein: 8 grams
• Carbs: 68 grams
• Fiber: 2 gram
• Iron: 12% of the Daily Value (DV)

Why is it called purple rice?

Most traditional Asian rice recipes, including this fermented purple rice recipe, combine black rice with white rice. The pigment from the black rice seeps into white rice, turning it purple color, hence the name ‘purple rice.’

A similar example is this Korean Japgokbap, a wholegrain purple rice dish made with a portion of black rice (with other pulses).

How fermenting black rice may contribute to our health?

Fermented black rice produces beneficial Lactic Acid Bacteria during the lacto-fermentation process. These microorganisms may be a good source of probiotics for our gut. Many studies have shown that a diversity of probiotics can help strengthen our immunity, which may protect our bodies from bad bacteria that can cause infections.

Fermented rice made from black rice contains an abundance of antioxidants. Apart from black rice being rich in beneficial plant compounds that offer antioxidant benefits, the fermentation process has been shown to increase antioxidant activities in plant-based food. It is proven by this article, specifically on black rice.

✏️ Antioxidants – Natural substances that help protect our cells from damage, potentially reducing the risk of chronic diseases.

Despite its many health benefits, black rice may contain toxic arsenic. But the good news is that soaking rice and fermentation with yeast can reduce its arsenic content.

Black rice is known to have phytic acids, which are anti-nutrients that can block the absorption of certain minerals. Soaking and fermenting black rice can reduce the phytic acid.

Black rice dessert contains minerals such as amino acids, vitamins, iron, fiber, and protein. So, they are not just sweet for nothing but may contribute to overall health.

This fermented black rice is lower in Glycemic Index compared to the fermented white glutinous rice version. It makes a gradual increase in blood sugar levels rather than a sudden spike.

Although comparatively fermented purple rice is better for diabetic people than white glutinous rice version due to lower GI, it is still high in sugar. So I can’t say how safe it is, so consult with your doctor if you have diabetes.

Ingredients to make Fermented Purple Rice

White Glutinous Rice – Look for the rice written “Glutinous Rice” on the package. This rice is common in Thai markets. Do not mistake this rice for Japanese rice. Though short-grain rice appears sticky and starchy, it cannot be used interchangeably.

Black Rice – Black rice can be found in the wellness aisle of supermarkets and maybe in Asian markets.

Ragi Tapai – A locally made dry starter culture used to make Tapai and rice wine. Typically in a round tablet form. It is also known as Ragi Tape in Indonesia, Apuan in the Philippines, and Look Pang in Thailand. You can find them at the Asian Mart.

How to make Fermented Purple Rice

1. Wash and soak the rice

Wash white glutinous rice and black rice separately and soak them in a separate bowl for at least 4 hours. I like to leave it overnight. Separating them can reduce the chance of the arsenic content leaching onto white rice.

2. Steam the glutinous rice – Total steam time (50 minutes)

1st steaming – black rice – Fill the steamer pot with water up to 70% and bring to a boil. Strain black rice and rinse it over tap water, and transfer the black rice to a steamer bowl (or a strainer basket). Steam them for 15 minutes. I like to cover the lid with a cloth so the water vapor won’t drip on the rice.

Add white rice & 2nd steaming – Once the timer is done, strain the white rice, rinse, and transfer it to the steamer basket. Mix them with a spatula and continue steaming for 25 minutes.

Rinse and fluff – Carefully remove the steamer basket with a clipper or gloves, and run through tap water to rinse the rice. Fluff with a spoon to make sure all parts of the rice touch the water.

Last steaming – Once done, bring the steamer basket back to the steamer and continue steaming for 10 more minutes or until it’s soft and fluffy.

3. Let it cool in a flat tray

Transfer the cooked rice to a flat tray, fluff it with a spoon, then spread it flat throughout the tray. Leave them to cool for about 30 minutes to 1 hour. I usually let it sit under the fan.

4. Spread the Ragi & mix well

Spread the starter culture evenly onto the cool purple rice. It’s very important to make sure the ragi is in fine powdery form before you do that. You can do so by blending the ragi in a dry blender. Or, like the photo below, rub the tablet on a fine tea strainer while moving the strainer around all surfaces of the rice.

The success of making Tapai also depends on how evenly the ragi is mixed with the rice. So, take your time mixing the rice and ragi well with a spatula.

5. Form the rice into balls and arrange them in a jar

Using a glove or clean hands, form the rice into bite-sized balls and arrange them in a glass jar. Lay a piece of cling wrap or banana leaves between each layer to avoid sticking. Cover with a loose lid, not airtight, just to allow minimal gas to escape.

6. Incubate/Fermenting

Leave it to ferment in a dark and warm place for 2 nights or 48 hours. My usual room temperature is about 20-29C – which is the ideal temperature for the rice to ferment.

How to know if the fermented rice is a success?

Once ready, you will see some water in the jar, which is the first indication of successful fermentation. Apart from that, successful fermented rice should not have any mold around it, which I need to remind you this part is quite tricky. Smell it after you open the lid, it should have a sweet and mild alcohol aroma.

Once all these indicators are checked, it’s ready to eat! Transfer the jar to the fridge and enjoy them chilled within a week.

Troubleshooting: How to know if the fermented purple rice is inedible?

• Black mold indicates that the rice is contaminated. If you see black mold around the rice, toss it immediately.

• If the rice is covered with spider web white mold, don’t take a chance, toss it. This can be because the starter culture was not spread evenly or because the glutinous rice was undercooked.

• Hairy, cotton-ish mold can easily develop if the rice is exposed to air. Some said you can scrape it off, and it’s still edible. I am a bit skeptical about this.

• If it smells bad or rotten, instead of vanilla-ish sweet, toss it.

Speaking from my experience, mold is very easy to appear on Tapai. It may developed because of the common mistake below.

Common mistakes when handling Tapai

Undercooked rice – Through my experiment, undercooked black rice led to dryness and created a spider web mold.

Ragi is not spread evenly – This can be due to ragi powder being less fine, do not skip blending or rub it onto a fine mesh strainer (the finer, the better). When placing the rice on the tray, make sure you use a flat tray so the rice is evenly spread.

Inappropriate packing – I have tried different ways to pack it, with or without banana leaves, whatever method you use, make sure all surfaces are covered and allow minimal oxygen to escape.

Using airtight container – The yeast needs minimal air ventilation to thrive, so make sure the lid you use when packing/incubating does not deprive them of oxygen entirely.

Important Tips When Making Successful Tapai – Fermented Rice

• Clean tools – Like making other fermented food, cleaning tools, ingredients, surfaces, and hands are crucial upon handling is crucial.
• Cook the rice well – Do not skip the soaking and stick with the steps and timing above. Always taste it first to make sure it’s soft before you turn off the heat.
• Buy good quality Ragi Tapai. Sometimes, the problem is not from you. Since each yeast culture is unique, test the ragi with a small portion of rice before you commit to a big batch. It is also important to buy ragi from a trusted source.
• When spreading ragi, make sure you place the rice on a flat tray so the rice is widely spread.
• Never skip to grind the ragi into fine powder before spreading it onto the rice. Use a fine mesh strainer (the finer, the better).
• Do not use metal containers, as they can interfere with microorganisms. Glass and ceramic containers are the best, banana leaves are highly recommended. Plastic containers, only if you’re fine with it.

FAQ

Why is black rice called forbidden rice?

Black rice was also known as forbidden rice during ancient China due to its nutritious content and rareness, and all people were forbidden from eating it except for royalty and wealthy people.

Does Fermented Purple Rice contain alcohol?

Yes, the fermented purple rice contains a mild amount of alcohol due to the fermentation process with the yeast. The level of alcohol also depends on how long you left the purple rice fermented.