Shelf life of bonito flakes?

I'm curious if anyone knows the shelf life of dried bonito flakes? I bought a small bag approximately 6 months ago and have used some (ie the bag has been opened). I can't find an expiration date on the bag and don't want to cook with them if they're past their use. Thanks!

Kristin Greene


Susan W. January 5, 2015
I enjoy a bowl of miso soup everyday, so my bonito gets used up fast. However, Nami, from (my go to for all things Japanese) says if the bonito smells and tastes good, it's fine. Keeping it room temp and dry is best. If it is still flakey and not clumpy, it's been kept at the correct humidity. I'd make a quick batch of dashi and not toss it.

Trampled, you eat bonito flakes right out of the bag? I just ate a pinch. Like the flavor, but not the texture.
trampledbygeese January 5, 2015
Eat them out of the bag? Yes, I sure do.

Bonito flakes are often used as a topping for all sorts of dishes, hot and cold, from cabbage pancakes (okonomiyaki) to miso soup. They dance when you put them on top of hot foods. It's great fun to watch.
Susan W. January 5, 2015
I didn't care for it straight. I love it in dashi. I do remember reading about the bonito dancing on hot food. I'll try a sprinkle of it on my miso soup tomorrow.

Speaking of miso...I am going to revive the miso thread. I became distracted by the holidays and a trip home to San Diego. Ready to get back to the miso project.
Kristin G. January 5, 2015
Thanks for the feedback! Agreed that sadly, I should err on the side of caution and chuck it.
trampledbygeese January 5, 2015
Unopened, I will keep bonito flakes for upto two years, but preferably one year. Opened, and kept away from moisture, it will keep well for 6 months, but can still be used upto a year.

It's a very shelf stable ingredient WHEN KEPT DRY. Traditionally, dried bonito can last for years without refrigeration (pre-fridge, pre-plastic bag days), but that's as a whole chunk, not shaven like we buy now.

My basic judge is the condition of the 'do not eat' packet. When that gets a bit heavy, I reserve those flakes for dashi and not raw eating. When the 'do not eat' packet gets swollen then I toss out the batch.

I've never freezed mine before, but that's a great idea.
trampledbygeese January 5, 2015
Sorry, desiccation packet. I've always just called the 'do not eat' since it's what's written on it, so that must be what it's called. Forgot that not everyone is as linguistically challenged as myself.

Also forgot to say, when in doubt, toss it out. Best judge is to use your senses. Do you see mold? Does it smell off? A small sample in your mouth make you gag? Your senses know a lot more than expiry date labels and strangers on the internet. We can't be there to see, smell, taste your bonito flakes, so it's up to you. You need to feel comfortable with it.
HalfPint January 5, 2015
Most bonito packages state one year in a cool, dry environment. My main worry is mold. So I tend to store it in the fridge or freezer. You have any doubts, just chuck it.
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