I am a middle school teacher and I have been baking with my students for the last 2 months. We bake on average about 16 loaves twice a week for a total of 32 loaves a week. We are using a modified version of the "Artisan Bread" in 5 minutes recipe (we use a much higher hydration (78%) to get a nicer crumb). The issue is this, the first two bakes (we can do 4 at a time in combo-cookers) are good with a nice oven spring. After that things start to get flatter and flatter. The last two bakes are definitely substandard. Each of the loaves gets the same amount of fermentation, bench rest, and time in the bannetons. I am perplexed why this might be the case. Any advice would be greatly appreciated. Thanks!