When I'm doing my two hour recipes, I have a max of three ovens built since it's too early for me to get enough parts to create more than that. Usually I'm working with just two ovens. So I just need to schedule out a 1, max 2 minute break since I only have to work with 1-2 ovens. This means I get a glass of water, take a restroom break, take my lunch hour, or whatever is convenient and available to me once every 4 hours for me to play the game. And by 4 hours I mean that two hour recipes means I have two more hours after the recipe is done for me to get to it before it spoils. Hope that helps!