I have recently baked a couple of chiffon cakes, overall I'm happy with the bake - the structure and flavor are very good. However I have a recurring issue with large holes in the sponge, see the picture below.
I suspect it is some of the meringue not being fully incorporated into the batter and that large blobs of meringue are causing these holes. I could see there were blobs of meringue, but I was concerned if I kept folding to incorporate them I would knock out air from the meringue so I left them. The meringue was pretty hard, and I found it tough going, the blobs just wouldn't break up.
Do I need to keep folding, or is there a way to break up these blobs? Or is my meringue too hard? If it's the meringue, how do I make it softer? Should I speed up pouring in the sugar and whip the whites less?