The Gekkeikan Okura sake museum have been making sake since 1637, with a nearly 4 century-old process. You'll be able to see how things have been done for generations.  At the museum you will also get a chance to see the sake brewery and get a sense of the traditional brewing process which involves a combination of water, malt, yeast and steamed rice. The different cut or variety of rice plays a big part in the distinction of the sake. If a grain of rice has a little grain shaved off, it is more bitter. Generally, the more grain that is shaved, the more sweet it will taste.