Why does my homemade bread always seem to have a dense or heavy texture, and how can I achieve a lighter, airier crumb?

I totally feel you, bread-making can be super finicky. I think I know what might be going on with your dense bread - are you overmixing the dough? When you mix the ingredients together, you want to just combine them until they come together in a shaggy mass, then let the yeast do its magic. Overmixing can develop the gluten in the flour, which makes the bread tough and dense.

Another thing to check is your flour. Are you using all-purpose flour or something else? All-purpose flour has a bit of protein in it that helps create a nice crumb, but if you're using bread flour or whole wheat flour, you might need to adjust your technique. Also, make sure your yeast is fresh and active - stale yeast can cause your dough to ferment too slowly and result in a dense loaf.

As for balancing yeast and rising time, try this: instead of adding more yeast, try reducing the rising time slightly. If you're letting your dough rise for too long, the yeast can start to break down the sugars and produce too much carbon dioxide, making the bread over-proof and dense. Aim for a gentle rise, and see if that helps you get a lighter crumb. And don't forget to keep an eye on your hydration levels - if your dough is too dry, it'll be tough and dense, but if it's too wet, it'll collapse and be dense too.

Lastly, try using a slower rise method, like a cold rise or a retarder. This will give your yeast a chance to work its magic without over-proofing the dough. I hope these tips help you get the perfect bread texture - it's all about finding the right balance and being gentle with your dough!