The percentage of flour to water is hydration, equal parts of water and flour is 100%hydration., and so on.

I don’t follow that rule however, I like my starter on the thick side. So what I have used say a 1/4 cup I will replace it with 1/4 cup of flour, however, I may only put 1/8 cup water.

It’s however you like your starter to be, is how you feed it to increase the level of starter you have.

You don’t really have to do that at all. You say you have 1/4 cup of starter and you want to increase. Look at your recipe and see how much starter it says you need. take a tablespoon or 2 of starter and build what you need from that, replacing what you use.

Example: Your recipe says you need 1 cup starter. Take a tablespoon of your existing starter and feed it 1-2 tablespoons of starter and 1-2 tablespoons water. Let it sit until it rises and falls, then feed it again, and do this until you have enough starter to make the bread you want..

You can use an egg wash on the loaf of bread. I don’t know what temperature you are using for baking your bread.

What I do is I preheat the oven at 450F I cover the bread with aluminum foil, and bake at 450F for 15 minutes. After 15 minutes I remove the foil and reduce the heat to 350F for the remainder of the time.

Another thing I forgot to mention, is that if you want that long proofing put it in the fridge over night and bake the bread in the morning. Putting the bread in the fridge extends the proofing time. I have often made bread dough but didn’t want or need to bake it off that particular day, and I have left the dough in the fridge for a week, and it was wonderful and very tasty.

Let me know how it goes

Any time you don’t get the oven rise you are looking for, it is usually because you over proofed the dough. Try reducing the amount of time you are proofing it. It could also be that you have a bad batch of flour. The rise doesn’t depend totally on the yeast, it also depends on the gluten….

Let us know how it goes after your next bake….