Cooking a roast showed me why my glass pieces crack during cooling

I was making a roast the other day and saw how the outside cooked faster than the inside. It got me thinking about how heat moves through things. In my glassblowing, I've had a lot of pieces crack after I take them off the pipe. I used to think it was just bad luck or my annealer acting up. But now I see that when I heat the glass, I might be rushing and not warming it all the way through. Like with the roast, if the heat isn't even, the stress makes it break. So I started turning my piece more slowly in the glory hole to get a uniform heat. This small change has really cut down on my cracked work, and it makes sense now.