Is miso gluten free? I know some miso is made with a barley starter. Is there a way to differentiate GF miso from normal miso by just looking at the packaging? Unfortunately I can't read Japanese.

Is there a website where can we find gluten-free miso online?
-younga
You are indeed correct that some types of Miso do contain barley and are therefore not gluten free. I've had the good fortune of visiting Japan several times, and often enjoy miso soup in this country at sushi restaurants, after grilling the poor waitperson.
There are many types of miso, some made with just soy beans and soy koji (called Hatcho miso, a favorite in Japan) and others made with barley and rice.
Here in the US I sometimes buy Gold Mountain brand Mellow White Miso. The ingredients list only water, rice, soy beans, and salt but of course there is always a starter culture. This product is explicitly labeled Gluten Free and it has never caused me any distress.
Since miso is a fermented product it can be expected to have a long shelf life. Also the fermentation breaks down some of the larger molecules that may irritate people that are slightly sensitive to soy.
Red miso (Akamiso) will usually contain barley and therefore gluten.
White miso is usually GF (Shiromiso).
I like miso and often use a bit of it in sauces.
I have also seen foil packets used to make miso soup that seem to be gluten free.
One time when I went to Tokyo on a business trip The Big Boss of the Japanese firm we were visiting took 3 of us Americans to his private club for dinner. He was amazed at my knowledge of Japanese cuisine, but of course from my perspective it was a necessity in order to avoid making myself ill in the middle of a business trip.
I seem to offer a link to gluten free miso soup on one of my many websites for people with celiac disease:
http://gluten-freestore.com/?s=miso&submit=GoLundberg Farms, a California rice producer with many explicitly GF items, offers a sort of Asian influenced rice sidedish called Rice Sensations, Ginger Miso. I seem to offer it for sale
http://glutenfreelive.com/index.php?k=miso&c=AllFood&x=0&y=0Generally speaking, miso is very high in salt, thus loaded with sodium. When I add it to a sauce I dispense with adding salt.
Some people make huge claims for the nutritional benefits of miso soup, this may all be true, but few people eat much of it in a given day so it is no miracle food.
I like miso because it tastes good to me.