So let me boil this down, and see if I understand it.
I start a youtube cooking channel, where every week I make a large Sunday dinner. After I’m done cooking I save the food and eat it throughout the week.
I keep detailed records of the food purchased for the videos, as well as any other expenses, such as buying a camera and microphone.
At the end of the year I deduct all of my “business” expenses from my personal income (good thing I kept my day job), decreasing the overall amount of taxes I owe. By far the largest expense is the groceries required for the Sunday dinner. (Coincidentally, I’m also spending less for my personal groceries.)
Maybe, somehow, I get 1000 subscribers, and I start earning money from Youtube. Now the expenses offset any income I earn from the videos, before being deductible from my personal income.
After three years of no profit, the business gets reclassified as a hobby, and I can’t deduct my Sunday groceries anymore.
If the IRS audits me, I show my careful records of expenses, detailed business plan, and logs of the hours spent editing videos and researching recipes, and hope that is enough to convince them that my single-take videos of making spaghetti with a stream of consciousness dialog about the afternoon’s Packers game represent a real business.