Rewana Bug (Potato Starter) - Traditional Māori Bread Starter

This is the traditional potato starter used to make Māori rewana bread. It's a fantastic starter that contains no commercial yeast, just potatoes, sugar, and flour. Quite possibly things you already own! It takes 4-6 days to make, and once it's ready, you can bake beautiful rewana bread. This is very similar to sourdough starter but made with potatoes instead.

Recipe Details:

• Day 0 (Initial Mix): 15 minutes
• Days 1-5: 5 minutes daily feeding
• Total Time: 4-6 days
• Makes: About 3 cups active starter
• Difficulty: Easy
• Special Equipment: Large bowl, colander, potato masher or fork

Rewana bread is a traditional Māori bread from New Zealand. Instead of commercial yeast, it uses a fermented potato starter known as a potato bug or rewana bug. This starter will leaven your bread much like sourdough does, it's made from natural yeasts found in the environment. It's traditional fermentation at its finest and takes between 4-6 days to make depending on how warm or cold your kitchen is. Once active, it will rise your bread beautifully with that slightly sour, complex flavour that comes from natural fermentation.

Why You'll Love This Recipe

• No commercial yeast needed: Uses natural fermentation from the environment
• Only 3 ingredients: Potatoes, flour, and sugar, that's it!
• Uses old potatoes: Perfect for using up potatoes that are getting soft or sprouting
• Creates beautiful bread: Once ready, makes the most delicious rewana loaves
• Similar to sourdough: If you love sourdough, you'll love this potato version!

What You'll Need

Day 0 (Initial Mix):

• 1 medium-large potato (or 2 small potatoes, about 150-200g total)
• 2 tablespoons mashed cooked potato (from the potato above)
• 1 cup plain flour (about 150g)
• 2 teaspoons white sugar
• ¾ cup potato cooking water (reserved from boiling the potato)

Save the remaining potato water for Days 2 and 4!

Days 1, 3, and 5 Feedings:

• ½ cup plain flour (about 75g)
• 2 teaspoons white sugar
• ¾ cup warm water

Days 2 and 4 Feedings:

• 1 cup plain flour (about 150g)
• 2 teaspoons white sugar
• ¾ cup warm potato water (from your reserved potato cooking water)

Day 0: Making the Initial Starter

1. Prepare the potatoes: Peel your potato (or potatoes). This is a brilliant way to use up old potatoes that are getting soft or have a few eyes sprouting! Cut into chunks if large.

2. Boil the potatoes: Place the potato small chunks in a saucepan and cover with water. Bring to the boil and cook until the potatoes are super soft, about 15-20 minutes. You want them really well cooked!

3. Save the potato water: This is important! When draining the potatoes, drain them over a bowl to catch ALL the potato cooking water. Don't pour it down the sink! Set this water aside , you'll need it for Days 2 and 4. Let it cool to room temperature.

4. Mash the potatoes: Mash the cooked potatoes with a fork or potato masher until smooth. Let them cool to room temperature.

5. Mix the initial starter: In a large bowl (you'll need room for it to grow!), combine:

• 2 tablespoons mashed potato
• 1 cup flour
• 2 teaspoons sugar
• ¾ cup of the cooled potato water

Stir everything together until well combined. It should be quite thick and paste-like.

6. Cover and keep warm: Cover the bowl loosely with cling film or a clean tea towel. You want air to get in but not bugs! Place somewhere warm in your house but out of direct sunlight. If it's summer and your kitchen is warm, the counter is perfect. If it's cold where you are, try these spots:

• In an airing cupboard
• In an insulated bag (like a supermarket cool bag) near a warm spot
• In the microwave (not turned on!)
• Near (not on!) a radiator

The warmer the spot, the faster it will ferment. Aim for 20-25°C if possible.

Days 1, 3, and 5: Regular Feedings

Each day, you'll "feed" your bug to keep it active and growing.

What to add:

• ½ cup flour
• 2 teaspoons sugar
• ¾ cup warm water

Method:

1. Uncover your bug and give it a look. You should start seeing changes, bubbles forming, the consistency changing, maybe a slight sour smell developing.
2. Add the flour, sugar, and warm water.
3. Stir everything together really well until completely combined.
4. Cover again and return to your warm spot.

What you should see:

• End of Day 1: The mixture should be becoming bubbly. You might see a few bubbles on the surface.
• Day 3: More bubbles, mixture might look jiggly, possibly some holes on top where it's "breathing."
• Day 5: Very bubbly and active, should look alive!

Days 2 and 4: Potato Water Feedings

On these days, you'll use the reserved potato water instead of plain water.

What to add:

• 1 cup flour (note: more than the other days!)
• 2 teaspoons sugar
• ¾ cup warm potato water (from the water you saved on Day 0)

Method:

1. Check your bug, it should be looking more active each day!
2. Add the flour, sugar, and potato water.
3. Stir well. Don't worry if it looks quite thick at first - once you mix in the potato water it will loosen up.
4. Cover and return to the warm spot.

What you should see:

• End of Day 2: Definitely bubbly now, jiggly consistency, holes forming on the surface where gases are escaping.
• Day 4: Very active! Lots of bubbles, might have increased in volume, should smell slightly sour and yeasty.

Day 6: Is It Ready?

By Day 5 or 6, your rewana bug should be ready! Here's what to look for:

Signs it's ready:

• Very bubbly and active
• Jiggly, almost alive-looking consistency
• Lots of holes on the surface
• Slight sour smell (like sourdough)

If it's not quite there yet: If your kitchen is cold or your bug isn't as active as you'd like, repeat the Day 1 feeding (½ cup flour, 2 teaspoons sugar, ¾ cup warm water) and give it another day or two. Cold temperatures slow fermentation down!

Daily Feeding Schedule at a Glance

Day 0 (Initial Mix):

• 2 tbsp mashed potato + 1 cup flour + 2 tsp sugar + ¾ cup potato water

Day 1:

• ½ cup flour + 2 tsp sugar + ¾ cup warm water

Day 2:

• 1 cup flour + 2 tsp sugar + ¾ cup potato water

Day 3:

• ½ cup flour + 2 tsp sugar + ¾ cup warm water

Day 4:

• 1 cup flour + 2 tsp sugar + ¾ cup potato water

Day 5:

• ½ cup flour + 2 tsp sugar + ¾ cup warm water

Day 6:

• Check if ready! If not, feed as Day 1 and wait another day.

Chef's Tips

Temperature matters: Warmth activates fermentation. The warmer your spot (within reason - not hot!), the faster your bug will develop. Cold kitchens = slower fermentation.

Save that potato water: Don't forget to save the potato cooking water on Day 0! You need it for Days 2 and 4.

Don't skip feedings: Feed your bug at roughly the same time each day. Consistency helps it develop properly.

Look for bubbles: Bubbles are a good sign! They mean fermentation is happening and wild yeasts are working.

The smell is normal: A slightly sour, yeasty smell is exactly what you want. If it smells rotten or off, something's wrong.

Use a big bowl: The bug will grow and bubble, so make sure your bowl has plenty of room!

Out of direct sun: Keep it warm but not in direct sunlight, which can kill the yeasts.

Be patient: If it's taking longer than 6 days, that's okay! Cold weather slows everything down. Just keep feeding it.

Troubleshooting

Q: My bug isn't bubbling. What's wrong? A: Your kitchen is probably too cold. Move it to a warmer spot and give it more time. Fermentation slows down in cold temperatures.

Q: It smells really sour. Is it off? A: A sour smell is normal and good! It's similar to sourdough. If it smells rotten, putrid, or like nail polish remover, something's wrong.

Q: Can I use the mashed potato from a previous dinner? A: Yes, as long as it's plain mashed potato with no butter, milk, or seasoning added. 

Q: I forgot to feed it one day. Is it ruined? A: Probably not! Just feed it as normal and it should bounce back.

Q: Do I peel the potatoes or not? A: You can do either! I've tried both ways. Peeled is more traditional, but unpeeled works too and adds extra nutrients.

Q: What if mold appears? A: If you see mold (fuzzy white, green, or black spots), unfortunately you'll need to start again. This is rare if you're feeding regularly and keeping it warm.

Q: How do I know it's definitely ready? A: It should be very bubbly, jiggly, and active. If you're unsure, give it another day or two of feeding.

Maintaining Your Rewana Bug

Once your bug is active and ready, you have options:

Option 1: Use it immediately Make rewana bread within a day or two of it becoming active. 

Option 2: Keep it going Continue feeding it daily with ½ cup flour, 2 teaspoons sugar, and ¾ cup warm water. Use it regularly to make bread, discarding some starter if it gets too much.

What's Next?

Once your rewana bug is active and ready, you can make Rewana bread!

If you're interested in other traditional bread-making methods, make sure you check out my sourdough masterclass.

You Might Also Like

Beginner's Guide to Lacto Fermentation: Another traditional fermentation method for preserving food!

The Reliable Sourdough Method: If you love this potato bug, try making a traditional sourdough starter. I have a course where you can learn all about starter to slice!

Homemade Ciabatta Rolls: More bread-making adventures with beautiful results!

Enjoy!

Del x

Making a rewana bug is such a fascinating traditional technique! Using just potatoes, flour, and sugar, you can create this bubbly, active starter that makes the most delicious bread. It's similar to sourdough but with a unique potato base. Takes 4-6 days of simple daily feedings, then you're ready to bake!