Since 2020, the Hawaiʻi ʻUlu Cooperative has been working with our friends at Voyaging Foods and the Hawai'i Farmers Union United to explore how best to scale production of ʻulu (breadfruit) flour.
Given Hawai‘i's current dependence on imported staples—including virtually 100% of our flours—drying and milling ʻulu offers a promising way to increase food security while decreasing food waste.
It's also worth noting that breadfruit turns into an excellent gluten-free flour with many uses and health benefits.
Download ‘Ulu Flour Production: A Visual Flowchart (PDF)
Here is how breadfruit flour is made:
Step 1: Receiving
Fresh ‘ulu is delivered at the starchy, firm maturity stage and without disease or damage by approved suppliers. Post-harvest handling and delivery methods follow Good Agricultural Practices (GAPs).
Step 2: Storage
Fresh ‘ulu is stored in a cool, dry room held between 41 and 55°F. This helps to slow fruit ripening and keep it firm without causing chill damage, which can discolor the flesh.
Step 3: Sorting, washing, and sanitizing*
Fruit is sorted to remove any softened pieces, and power-washed to remove field debris and sap. Fruit is then sanitized by soaking for 1-2 minutes in a food safety-approved sanitizing solution. Keeper Pro at 50 ppm may be used for certified organic operations, or chlorine at 100-200 ppm for conventional.
Step 4: Quartering
Fruit is quartered and placed in a citric acid bath to minimize oxidation. For “peeled” breadfruit flour, the skin and core are removed before quartering; for “whole” breadfruit flour, peel and core are left intact.
Step 5: Slicing / Shredding
Breadfruit quarters are thinly sliced or shredded using a commercial food processor.
Step 6: Drying*
Shreds or slices are placed on a drying tray in a single layer and dehydrated between 140 to 165°F until crisp to the touch, with a water activity (aw) of less than 0.6. Exact time depends on dehydrator equipment and thickness of fruit on trays, and is usually between 6-8 hours. If desired, dried breadfruit can be stored in an airtight container for up to 6 months as sufficient volumes are consolidated for milling.
Step 7: Milling
Dried ‘ulu is milled in a certified kitchen. A hammermill with sifter screens HMS 0.020 and HMS ¼” provide particle or grain sizes appropriate for flour production.
Step 8: Packaging
‘Ulu flour is packed into airtight, food-grade bags or containers and labeled with lot code and/or date and package weight.
Step 9: Storage
The finished product is cased and stored in either ambient, refrigerated, or freezer storage and protected from moisture until use or distribution. Shelf life in sealed packages is generally 6-12 months in ambient conditions and can be longer if stored at lower temperatures. Shelf life can be extended by keeping flour in the refrigerator.
Step 10: Distribution
If selling ‘ulu flour commercially, finished product is packed in clean shipping boxes and distributed or picked up by the customer.
*Denotes a critical control point (CCP), a step in the food production process where preventative measures can be applied to prevent, reduce, or eliminate a food safety hazard, such as bacterial growth.
Thanks to support from the Atherton Family Foundation, we have been able to scale our flour operation and have learned A TON in the process! As a result, ‘ulu flour is now more accessible than it was before: you can find 1 lb. bags at several natural food stores throughout the islands and bulk bags are available on our online store.