Question: How did they thicken coconut cream to make haupia in old Hawaii? I know they didn’t have cornstarch. I heard about pia. Is this plant hard to grow? I was given one and am so scared about taking care of it. It’s rare, no? Does it go moemoe (sleep) in winter in Hawaii? What do I do then? — Kupuna ‘Iuliana
Answer: Pia is an important laau (plant) carried here by ancient Polynesians. It is somewhat rare in modern Hawaii.
It does go dormant in Hawaii’s winter. This is one of the reasons it’s harder to find and malama today. We forget where it’s planted and dig up the area to fill the puka in our landscape, or alien weeds and aggressive grass take over the growing area.
The leaves wither, turn brown and shrink, and pia "rests" in midwinter in Hawaii. Mark the spot with a ring of pohaku (stones) or a stake and name tag to help you remember where the pia is, alive but moemoe. Do not water it too much, but keep the soil moist. Water the area about once a week in the winter if there is no rain.
Watch for pia to emerge from dormancy in the spring. A new green shoot will poke up from the soil and grow into a plant with lobed leaves on long stalks. The flowers are small and greenish with purple highlights.
Another common name for pia is Polynesian arrowroot. The underground roots are called tubers, and they are ono food that is high in starch. The starch from the roots was used to thicken haupia, kulolo and other traditional Hawaiian treats and desserts.
Hawaiians of old grated the tubers, which look like a small potato, and soaked and washed them for several days. The starch grains would settle out in the water, and the rinsing would remove the bitterness. The starch was then added to coconut milk, and the mixture was baked or boiled. Any leftover pia starch could be shaped into small cakes, sun-dried and saved for a future culinary use.
The stems are fibrous, and another use is to weave or plait the white satiny fibers, an old Hawaiian art form.
Pia is a laau lapaau (plant with medicinal uses) as well. Raw tubers were used to treat diarrhea and dysentery. It also has similar uses to modern-day cornstarch, such as for laundry and thickening of other dishes such as stew, gravy and soup.
Pia is native to Southeast Asia. People have carried and transplanted it around the tropical world. It is in the Amaryllidaceae family, along with orange Amaryllis lilies (an old-time kamaaina favorite), tuberose, sisal or agave, century plant, narcissus, spider lilies, Amazon lilies, blood lilies, clivia and many other unusual flowering plants.
We should grow and cultivate pia in our gardens to help perpetuate this unique Polynesian introduction. Making traditional haupia would be a learning adventure for your ohana or Hawaiian studies project. It also makes you appreciate canned coconut milk and cornstarch in our compressed modern times.