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”.
Unless it’s a single origin bean, it’s probably a blend anyway. I just blend the leftovers with the new beans and call it a good cup. I’ll try to find a complimentary roast, though. e.g. mixing a light roast with a dark roast leads to an odd cup.