1. When wood looses humidity, it shrinks. The opposite is also true. Loss of humidity is the most common cause of wood cracking.
2. Wood tends to establish balance of humidity with the surrounding. If wood is „drier than the air”, in some way, it will absorb the moisture from air, if it is „wetter” it will release it into air.

You don’t need to understand fully the relation of stability between wood and air, even though an easy table which represent it can be found on wikipedia. What you need to know to take good care of your instruments is that air humidity should be between 40% and 60%. It is good to know that it is a bigger problem if the air is too dry than too wet, and most problems come during winter when air humidity inside houses drops significantly. It is due to the reason that air at lower temperatures can absorb less water in total than at high temperatures. For example air at 20 °C and relative humidity 50% has much more total humidity than air at -10 °C and 50% relative humidity. When dry air in winter comes from outside, by airing the room, and is warmed up to room temperature, its relative humidity becomes very low. Winter times are the times when you have to take most care of your instrument. It is very good to get yourself an air humidity monitor (hygrometer), and try to keep humidity in winter high enough. Good news is that very low humidity is also not good for humans, and amazingly humans and wood have same optimal humidity which is between 40% and 60%. So you will also benefit from keeping humidity level optimal for your didgeridoo.
Even 30% is acceptable if you gradually reach that point and gradually go out of it. But in winter time many people have around 5% humidity inside the house! That is the real problem and one of two most common causes of cracking. If you want to check your humidity, you need calibrated moisture meter as non calibrated can be very off. On the calibrated models you usually have something like +-3% written on them.

Accustom your didgeridoo to playing!

When you receive a new instrument, take into account that it has probably been playing for a very few time before you got it. Therefore you need to accustom it to playing. If you buy a second hand instrument, you can also ask how much has the didgeridoo been played before, and in what state it is in, regarding playing. Didgeridoos receive an extra amount of stress compared to other instrument, and that is water and moisture that is produced when you play.
Saliva and vapour from your breath both penetrate into your didgeridoo from the inside to a certain extent. When they do, the wood in the inside of didgeridoo, especially in the mouthpiece area swells, while the outer layer remains about the same as before. It takes time for the instrument to get accustomed to the new level of humidity. Thus it is always advised to gradually increase the amount of playing with every new instrument. You can start with something like 10-20 minutes max (the harder the wood the less playing) and increase by 5 minutes or so, every five days,  maybe leaving some day of rest. Once your reach hour and a half, it should be accustomed to playing, and no longer as prone to cracking.

It is a good practice to rotate instrument when you play, so saliva does not make only one path down the instrument.
After each playing session put your instrument upright for about 10 minutes so that saliva pours out from it freely. If you lean it on the wall put some cloth on the mouthpiece to protect the instrument from direct contact to the wall. However this is no guarantee that nothing will happen to the instrument, since wood is always alive material. Some wood is much more prone to cracking compared to the other. Even if you have tough time with your new instrument, know that this taking care makes a bond with you, and eventually every crack reduces inside stress of wood and makes it more stable. Remember it is a good practice to change instruments when you practice, if you practice for several hours.
If you have any further questions, or directions how to treat small cracks, contact us by mail.

Sometimes didgeridoos crack when they change the place and owner even when all the mentioned measurable variables are in the right place. When that happens, you can still accept it and make the repairs needed, without the exact understanding of how it happened.  But in case of doubt, change your humidity meter to a better one.
One more important aspect of taking care of your didgeridoo is cleaning. But it is a topic that is not as crucial as the cracking and we will dedicate separate article to cleaning. For now know that we advise that you wipe the inside of the mouthpiece with a piece of cloth after EACH playing!One more article will be dedicated to repairing of cracks.For another good article on didgeridoo care, you can visit Didgeridoo Breath.