As a newbie, I don't know anything about shincha but am eager to hear more.
I see in the poll, some responders indicated they may not know what shincha is, so, here is shincha 101. This is Japanese tea terminolgy. Chinese has a much more convoluted set of terms.
...literally means new tea in Japanese. It is always first flush, but not all first flush is shincha. Shincha is packaged for immediate sale upon final processing of the leaves. Shincha is traditionally off the store shelves by July.
is simply first flush Japanese tea. Not all ichibancha is shincha. Much of ichibancha is placed into cold storage as aracha in very large airtight bales. Ichibancha goes through final processing throughout the year to provide consumers with the freshest teas possible.
is commonly refered to as farmer's tea. It is tea that is fully processed up to the final sorting of the leaves. So, it will have all sizes of leaf and as well as leaf stems and veins. Most ichibancha is placed into huge cold storage rooms as aracha. Aracha is usually the very first tea to be consumed by tea farmers and fortunate consumers since it is the first tea to be completely processed.
When I receive a parcel of heat sealed Japanese tea, I place it into cold storage...aka, the TeaFridge. This will keep fresh sencha freshest for extended periods of time. Once the heat sealed bag has been opened, it is not recommended to place it back into cold storage, but it can be done with proper sealing of the opened bag. It is critical to keep tea that has been placed into the fridge away from odors, tea leaves are magnets for odors.
Today, sencha Fukamushi Superior is in my cup so far. Delicious. This is ichibancha sencha, but not shincha, that is 11 months post harvest but has been properly cared for throughout this period. In a month or so, I will be able to purchase this tea as shincha!