How to bake climbing chalk

All climbing chalk powder is essentially the same: it’s all magnesium carbonate, pretty much inert & there are very few differences between brands. One of the things that does make a difference though is how much water has been absorbed by it. If you leave your chalk bag outside in the rain or if you keep large quantities of chalk outside of an airtight waterproof container some moisture will be absorbed, changing the feel of the chalk & its effectiveness.

A simple trick to turn low-quality or wet chalk into high-quality chalk that feels brand-new & dry is to bake it. It’s one of those tricks pro climbers use to get the best performance out of their chalk. Jerry Moffat was rumoured to have done exactly this at Camp 4 in Yosemite when he first worked out world-first boulder problems like Thriller and The Force.

Baking your chalk is pretty simple. First, a word of warning: use the oven to bake your chalk. Do not microwave your chalk. There’s not enough moisture content in chalk to make microwaving safe. Do this enough and all you will achieve is ruining the magnetron inside your microwave.

Spread out your chalk on a tray or baking paper & put it in the oven. Set your oven to about 120 degrees Celsius. This is enough to boil off the moisture, no need to put it any higher. Make sure you turn off the convection. You don’t want the heated air blower to turn your oven into a chalky mess.

Leave the chalk in for about an hour if you want to just bake off the excess moisture in chalk that has been lying around for a while. If you need to dry out chalk that has been really wet, you may want to repeat this 1-hour process a couple of times until you are satisfied with the dryness.

After you finished, turn off the oven & let the chalk cool down. I like to put my dried chalk in little ziplock bags for that bad-ass drug dealer feel. Now’s also a good time to grind your chalk if you want to change the feeling & consistency.