The batter should be thin
Kutsinta batter is much thinner than ordinary cake batter. That is expected here. Avoid adding flour simply because it looks watery, as changing the ratio will affect the finished texture.
Starch settles as the batter stands. If you are steaming several batches, a gentle stir before each round keeps the first and last pieces more consistent.
Judge doneness by the center
The surface can look set before the middle has finished cooking. Check one of the fuller molds: the center should hold together without liquid batter.
The video uses a 15–20 minute steaming time, but deeper or larger molds may need longer. A glossy, slightly sticky surface is normal and does not automatically mean the kutsinta is undercooked.
Gentle steam gives you more control
Keep enough heat to maintain steady steam without violently boiling the water underneath. Condensation dripping from the lid can leave wet patches on the surface.
If the tops look watery, check for dripping condensation and test the center before deciding that the whole batch needs substantially more cooking.
Let the texture settle
Kutsinta becomes easier to handle as it cools. If a piece stretches or tears when you try to remove it, give the remaining molds more time before trying again.
Loosen the edge gently rather than digging underneath. A light coating of oil and adequate cooling should do most of the work.