Bombs tend to be of fundamental use in the game. To let Link stock them up, he first needs something to hold them. Hence, Link is subjected to get a bag. However, the bags come in three different sizes. The player will further want to upgrade the bag to increase the storing capacity in the proceeding levels.
How To Get a Bomb Bag In The Legend of Zelda: Skyward Sword HD
This guide would explain the location of a Bomb bag.
It is easy to have the bomb bags in the game. And even easier to find the bombs. When you go across the Eldin Volcano, you will find bomb flowers everywhere. It would be easy to pick them up and use them. But you won’t be having a place to store them.
You can find the Bomb bag in the Earth Temple which is the second dungeon in The Legend Of Zelda: Skyward Sword HD. You can enter the dungeon after completing the Skyview Temple and getting all the five key pieces in Eldin Volcano.
To find the bag, you need to go to the mini-boss room located in the Earth Temple by jumping across three stone blocks and using Digging Mitts to reach the chest. After getting in the dungeon you will face two Lizalfos. Killing them easily would be a tough call but if you hit them on their weak point, you can beat the crap out of them. After defeating them, a chest would appear. On opening the chest you would find out the bomb bags.
Now, you would be able to take those flower bombs and store them in the bag. However, you won’t be allowed to collect more than 10 of them but upgrading the bag, would ultimately enable you to have more of them.