Economics. You have a week’s worth of food in the pantry. Over the next month buy a little extra each time you go to the grocery store. Now you have two week’s worth of food. Continue shopping weekly or whatever your routine was. Eat the oldest items. Costs a little during the month you bought extra. Or use coupons and buy specials and sale items. But it costs a lot less than freeze dried food in a bucket and is fresher and tastes better.

Also get a ten gallon container for water and rinse, clean, and refill it a couple times a year.

Put the extra long term stuff in your bunker. Use regular food for the annual power outages and extreme weather.