I’ve done a bit of fieldwork in Sarawak (Borneo) and one year had the great fortune of partaking in pre-celebratory festivities leading up to Gawai, the celebration of indigenous culture in Sarawak. This recipe comes from the Headmaster of the longhouse at the mouth of the Batang Ai river. This was originally posted on sarawakfungi.org, but that site is no longer being maintained so I’m reposting it here.
1. Cook 2 kg of sticky rice with two volumes of water (i.e., twice as much water as rice), then allow it to cool to room temperature.
2. Mix in 1 kg of yeast (special yeast cake found in shops in Sarawak).
3. Wait one week.
4. Bring 2-3 kg of sugar (depending on taste) to boil in 20-30 L of water, cool to room temp, then add to the rice mash.
5. Add 0.5 kg yeast (same special yeast cake as before), mix and let ferment for at least one week.
6. Serve in small glasses at room temperature.