The ideal number of brood boxes for a beehive to have is one.
This is because the brood chamber is where the queen lays her eggs, and it is the space in the hive where the worker bees take care of the growing bees who are not yet adults.
A single brood chamber is the most efficient setup in terms of being able to maintain the right temperature and humidity that the brood needs to develop. If you have more than one brood box, it can be difficult for the bees to maintain the correct conditions.
However, while you should only have one brood chamber, you can have more than one box in the rest of your hive.
If you’re using a Langstroth hive, then you’ll be using “supers” for the boxes of your hive that are not the brood chamber.
To be more precise, if you’re using foundationless frames for your brood chamber, then you’ll have one box which is your brood chamber, and then you’ll have two or three supers on top of that.
This allows you to harvest the honey from one of the supers, while the bees fill the other one or two supers with honey for themselves.
The reason you can’t just take honey from the brood chamber is because that’s where the bees store their food for the winter. They need enough food to last them all the way through to the end of winter, because there’s no nectar available for them to forage at that time.
When you put a super on top of a brood chamber, you put a queen excluder between the brood chamber and the super. The queen excluder has holes in it which are big enough for worker bees to pass through, but not the queen. This means that the queen stays down in the brood chamber and doesn’t lay any eggs in the super.
The reason you want to do this is because you don’t want eggs and brood in your honey. It’s safe to eat, but it’s a bit gross and it’s not what you expect from honey. The supers are purely for honey, and that’s why you want to keep the brood out of them.
So, in summary, you should have only one brood chamber, but you can have more than one box above the brood chamber if you’re using a Langstroth hive.