This is a question we get from time to time. It reminds me of a quality control inspector I knew who carefully monitored any aging produce in the foodservice warehouse. Excess-inventory items can quickly overstay their welcome. Slowly dehydrating, such items to the point the inspector described the product as being “On life support,” and compelling the associated buyer to make the call to donate or otherwise remove the aged inventory. It’s difficult but the question to ask is this: Is the product still a value? In the case of five-day old boiled and stored refrigerated potatoes, it could be that these are still alright. This is also at the very end of the storage life of 3-5 days (and under ideal refrigeration conditions). This scenario is likewise the equivalent of something on life support. It might-be alright, but why take the chance? Potatoes are a very economical vegetable, and whatever savings you realize may not be worth the risk. It’s always best to err on the side of food safety. Discard the aged product and start fresh.