In our house, we generally go for variety in our coffee beans. That means when we are finishing one bag, we’re going to open a different bag with totally different beans inside.
What do you do if there aren’t enough old beans to make a full serving of coffee?
It may be heresey, but I mix the final old beans with a few beans from the new bag and call it my “bonus blend”.
Sometimes if I’m feeling classy I’ll grind the rest and set them aside to make cold brew with later. That’s more forgiving so I do it to use up old, stale beans that I end up with for whatever reasons.
Most of the time I don’t care and I just top off the weight with whatever I’m using next and drink whatever comes out. It’s usually fine, and when it’s not it’s at least novel.