Aiyu is surprisingly hard to come by outside of Taiwan. I had no idea it was hard until I left. Turns out, the Aiyu plant is found only in Taiwan and certain East Asian countries. Outside of Taiwan and Singapore --- according to wikipedia --- it's pretty much impossible to find the jelly.
When I was in Taiwan, we never make our own aiyu. It's like you would never make your own tofu, you just go to the tofu store to buy it. At every local market there's usually a stand that sells aiyu along with grass jelly and other sorts of random snack stuff, so we'd either buy it from the vendor, or even easier, eat it at a local snack stand that sells chilled grass jelly or aiyu jelly.
Aiyu is usually served quite simply --- in a bowl with sugar water. It's popular in the summer and is considered a good snack because: (a) it has pretty much zero calories; (b) it is rich in pectin, which is supposedly good for digestion; (c) Chinese categorize aiyu as "cold food", which means it cools down the body from the summer heat.
Back to getting aiyu outside Taiwan....they do sell aiyu jelly at Chinese supermarkets like Ranch 99, but it is never "fresh" and "pure". The thing is, real aiyu jelly only stays gelatinous for a day or two. Afterwards they dissolve back into water. So make the aiyu stay gelatinuous, the supermarket brand aiyu is either fake (it has no real aiyu in it, just some flavored jelly) or has some additional substance and preservatives added.
Last year, before my mom came to visit, I asked her to find aiyu seed for me. This turned out to be a lot harder than I thought. Because nobody makes it besides professional sellers, it's not sold at supermarkets or grocery stores. My mom ended up finding it at a very traditional grocery store that only carried it every now and then when it was available.
With the weather warming up, I decided today was the day to bust out the seeds and make my own aiyu!
Aiyu is very simple to make. You just need the seeds, water, and your hands. The water cannot be bottled, distilled, or filtered, should just be tap water, cause I think it requires the minerals in the water to activate the pectin released from the seeds.
The seed purchase didn't come with a bag for me to put the seeds in, so I had to improvise --- I took a single stocking (can't have holes in it), rinsed it many times, put the seeds in, and tied a knot at the end.
Then I put the bag in a bowl of water and rubbed it with my hands. The seeds become very slimy immediately, which is kinda...yucky, but that's the pectin coming out :P after 5-7 minutes of thorough sock rubbing, I left the bowl for the jelly to take shape.
This is what it looks like after 1.5 hours:
And it's ready to be eaten!!!! :D
I squeeze half a lemon over some spooned aiyu jelly, drizzle some agave, and voila, homemade aiyu!!
We have several more bags at home and this is going to be my goto summer snack for a while!