Amazake: Japan's Natural Sweetener

Amazake (甘酒) translates to "sweet sake," but don't let the name fool you - it's barely alcoholic, if at all. What it is is naturally sweet, creamy, nourishing, and one of the most versatile ferments you can make. Think of it as a living sweetener: rice koji transforms cooked rice into a thick, sweet porridge through pure enzymatic magic, no added sugar required.

In Japan, amazake is traditional winter festival food, sold steaming hot at shrines during New Year celebrations. It's also drunk cold in summer as a refreshing, energizing beverage. Some call it "drinkable IV" because it's so nutrient-dense - full of B vitamins, amino acids, and glucose that your body can use immediately. It's what Japanese grandmothers give to children and the elderly for strength and vitality.

But amazake isn't just a drink. It's a natural sweetener you can use in place of sugar in baking, smoothies, porridge, and desserts. It's a marinade base for fish and vegetables. It's a dairy-free cream for soups and sauces. Once you've made it, you'll find dozens of ways to use it.

Makes approximately 1 litre

Ingredients:

• 200g rice koji (fresh or dried)
• 400g cooked short-grain rice (white or brown)
• 600ml water (approximately - you may need more or less)

Equipment:

• Heavy-based pot or rice cooker with "keep warm" function
• Thermometer
• Whisk or spoon for stirring
• Clean jars for storage

Method:

Step 1: Cook the rice

1. Cook 400g of rice as you normally would (this will be about 150-180g uncooked rice, depending on variety). Short-grain white rice is traditional, but brown rice works beautifully too and adds nuttiness.
2. Once cooked, let it cool to about 60°C. If it's too hot, it will kill the koji enzymes. If it's too cool, fermentation will be slow.

Step 2: Mix with koji and water

3. In a heavy-based pot, combine the cooked rice, rice koji, and water. Stir well to break up any clumps. The mixture should be quite loose and porridge-like - thicker than soup, thinner than risotto.
4. Check the temperature. You want it at 55-60°C for fermentation. This is the sweet spot where the enzymes work most efficiently.

Step 3: Ferment (maintaining temperature)

5. This is the crucial part: You need to maintain the temperature at 55-60°C for 6-10 hours. There are several methods: Rice cooker method (easiest):
   • Put the mixture in a rice cooker and set to "keep warm" function
   • Prop the lid open slightly with a wooden spoon or chopstick (this prevents it from getting too hot)
   • Check temperature periodically and adjust lid position as needed
   Stovetop method:
   • Keep the pot on the lowest possible heat
   • Check temperature every 30-60 minutes
   • Remove from heat if it gets above 60°C, return when it drops below 55°C
   • Cover with a lid, but check regularly
   Thermos/esky method:
   • Pour the hot mixture into a preheated thermos or wrap the pot in towels and place in an esky
   • This is less reliable for maintaining steady temperature but works in a pinch
   Oven with light on:
   • Some ovens maintain 55-60°C just with the light on
   • Use an oven thermometer to check
   • Cover the pot with a lid or foil
6. Stir occasionally - every hour or so if you're around. This helps distribute the enzymes and ensures even fermentation.
7. Taste as you go: After 6 hours, taste the amazake. It should be noticeably sweet. The longer you ferment (up to 10 hours), the sweeter it becomes. When it tastes sweet enough for you, it's ready.

Step 4: Stop fermentation and store

8. Once it's sweet enough, you need to stop the fermentation by heating it briefly. Bring the mixture to a simmer (about 80-85°C) for 5 minutes, stirring constantly. This kills the enzymes and stops further fermentation.
9. Let it cool, then transfer to clean jars. Store in the refrigerator for up to 1 week.

Texture Options:

Chunky amazake (tsubu-tsubu):

• Leave it as is after cooking - you'll have visible rice grains and a porridge-like texture
• Traditional for drinking warm

Smooth amazake:

• Blend in a high-speed blender until completely smooth and creamy
• Better for using as a sweetener or in smoothies

Concentrated amazake:

• Use less water (about 400ml instead of 600ml) for a thicker paste
• Great for using as a sweetener - thin with water or milk as needed

How to Use Amazake:

As a drink:

• Thin with water or plant milk and drink warm or cold
• Add a pinch of salt and grated ginger (traditional winter version)
• Blend with frozen fruit for a smoothie
• Add to coffee or matcha as a natural sweetener

As a sweetener:

• Use in place of sugar in baking (roughly 1.5 cups amazake = 1 cup sugar, but reduce other liquids slightly)
• Stir into porridge or oatmeal instead of honey or maple syrup
• Sweeten yogurt or chia pudding
• Use in salad dressings for subtle sweetness

In cooking:

• Use as a marinade base for fish or chicken (the enzymes tenderize while adding sweetness)
• Stir into soups or stews as a thickener and flavor enhancer
• Make amazake ice cream (blend with coconut cream and freeze)
• Use in place of cream in vegan sauces

Troubleshooting:

Not sweet enough:

• Temperature was too low (enzymes work slowly below 50°C)
• Fermentation time was too short
• Temperature was too high (above 65°C kills enzymes)
• Solution: Try again, monitoring temperature more closely

Tastes sour or alcoholic:

• Fermented too long
• Temperature wasn't consistent, allowing wild yeasts to take over
• Solution: It's still safe but tastes off - compost and start fresh

Too thick:

• Add more water during fermentation or when serving

Too thin:

• Ferment with less water next time
• Reduce on the stove after fermentation

Cultural Context: Amazake in Japan

Amazake has been made in Japan for over a thousand years. There are two types: one made with sake lees (sakekasu amazake) that's slightly alcoholic, and this version - made purely from rice and koji - which is alcohol-free and safe for children, pregnant women, and anyone avoiding alcohol.

Historically, amazake was considered medicine - a quick source of energy and nutrients for people recovering from illness. Street vendors would sell it hot in winter and cold in summer. It was given to nursing mothers for milk production, to children for growth, and to the elderly for vitality.

In recent years, amazake has experienced a renaissance in Japan as people rediscover traditional foods. It's now marketed as a "superfood" - the natural sweetness means it's low GI compared to refined sugar, and it's full of vitamins, minerals, and beneficial enzymes (if not overheated).

Why This Matters

Amazake is proof that sweetness doesn't require sugar. The koji's enzymes - the same ones used to make sake, miso, and soy sauce - break down rice starches into simple sugars. No bees required, no cane fields, no processing. Just rice, koji, warmth, and time.

It's also ridiculously versatile. Most ferments have one primary use, but amazake works as a drink, a sweetener, a marinade, a thickener, and a base for desserts. Once you've made it, you'll understand why it's been a staple in Japanese households for centuries.

Rice koji available at [The Fermentary shop link].
Already made shio koji and shoyu koji? Check out our full [koji recipe collection].