A very common practice is cutting calamansi in middle crosswise prior to squeezing. We are doing this because it is easy to do so. Second, halves calamansi are easier to squeeze. Lastly, we are attempting to maximize the usage of calamasi, e.g. half calamansi per serving of pancit.
When cutting calamansi in its middle part, we are also cutting the seeds. Those cut seeds contribute to astringent taste of calamansi juice. This might not be an issue for everyday home use but we should pay attention to it when it comes to juice production for commercial purposes. Astringent tasting calamansi juice (mapakla) is not acceptable to consumers.
The right practice is to cut the citrus on its tip near the stalk to avoid seed cut. We need an extra effort in order to squeeze it but we will be able to eliminate the astringent taste.
Mechanical extraction of calamasi may break some seeds from time to time. In this case, an enzyme called niringinase is used to removed the astringent taste.
Drop a comment if you know other ways to eliminate astringency in calamansi juice.