Although I have never been to Japan, almost everything I read on tea says that Genmaicha is a favorite everyday green tea drink in Japan. Essentially it is Bancha, which is a very low-grade green tea, mixed with toasted and popped rice. When you open a bag of Genmaicha there is really a sparse amount of green tea and a lot of toasted rice and popped rice, which looks exactly like popcorn, but smaller. It doesn't look like a green tea drink to me, but more of a snack pack.
History
According to ancient Japenese legend, during the fifteenth century, a servent named Genmaicha was serving his master, a samuri warrior, some tea when a few grains of rice accidently fell out of his pocket and into the pot. The warrior was so infuriated that his servent had "ruined" a perfectly good cup of tea that he chopped off his head. He decided to drink the "contaminated" cup of tea anyways though, and discovered that he enjoyed the distinct flavor of the tea and rice infusion. In honor of his poor servent, he insisted that this combination of tea and rice be served every morning and named it 'Genmaicha' (as cha is the name of 'tea' in Japanese). Another story claims that Genmaicha was a way for frugal Japanese housewives to stretch their tea with the addition of rice to get the most out of their precious tea leaves.
My Thoughts
I just tried Genmaicha for the first time today. I have been avoiding it, only because I know it is made from a really low grade of green tea leaves, called Bancha, and mainly consists of toasted and popped rice. From a health viewpoint, I can't imagine there being anything really healthy about drinking Genmaicha. Sure it has a little bit of green tea, but the quality is pretty low and I doubt you will find much in the way of polyphenols and catechins in the Genmaicha green tea leaves. It is the polyphenols, specifically catechins, that give green tea its health benefits. Here are several articles:
I heated the water to about 180 - 190 degrees and let it steep for about 3 minutes before pouring it into a cup. After a few tastes, I had to toss out the rest of the cup. It tasted almost buttery to me and had a lasting flavor that seemed to stick with you. It was not thirst quenching at all, and I tasted no hint of a vegetal flavor as you often hear from articles. All I had was the incredible urge to drink something else to rinse out the pronounced flavor.
My guess is that this is just an inexpensive tea due to the low quality of the green tea leaves, and toasted rice and popped rice is tossed in to mask the bitterness of the low quality green tea leaves. If you are okay with this and actually like the toasted, buttery flavor, then Genmaicha is for you. However, my wife and I will not be carrying this in our green tea business, Relax Sip Enjoy, because I just can't in good conscious offer green tea that I don't believe is healthy and of good quality.
I will try to drink an entire cup this evening to see if it tastes any better the second time :)