Hi Steph, fatback is a cut of fat that comes off of the back of a pig (https://en.wikipedia.org/wiki/Fatback). It's often sold salted in stores, but it doesn't need to be salted to work for this.

Hi Lucas, yes the base can be frozen. How long depends on the type of freezer you have. Most home freezers cycle the temperature up and down to prevent frost from building up on the inside of the freezer. This causes freezerburn over time so I wouldn't recommend storing it for more than a few months. If you have a deep freezer you can probably get away with storing it for longer.

Thanks Michael! I made this recipe back in 2009 when I lived in NYC, and have since moved to Japan and made a lot of improvements to this. Never really thought about cutting the Tonkotsu with dashi, but this makes sense. One of my favorite ramen shops in Sapporo cuts their Tonkotsu with shrimp stock. Also thanks for the Akamaru sauce tips. I've been working on an umami chili sauce by fermenting chilies with Koji, will have to try mixing it with miso, and aromatics.

Hi Patrick, you can make it the same way as specified in this recipe, but you will need to increase the cooking time by 3-4x. Due to the extra evaporation you will also likely need to add water periodically.

Thanks Aboud! It's quite a project, but I'm glad to hear you found it rewarding. As for the bones, they're not good for much. As you've probably seen, the bones crumble apart and they don't have a ton of flavor left. Even if you blend them the result will be quite gritty, so I wouldn't recommend it unless you have a pet that you you want to feed more calcium to.