Sometimes food will be soggy or more chewy than normal. This is normal in some foods, but generally speaking the food should be crisp and fluffy. If the food is soggy it is most likely that there was still water in the food, or that water from the air got reintroduced into the food. Sometimes water can hide in seeds of food, like watermelons or strawberries. If this happens then you may put the food into a mylar bag dry and crispy, and when you pull it out later it is soggy. This is likely because there was still water in the food.

There is a myth that this can be caused by the oxygen absorber or descant packet. This is not true. This will only happen if the oxygen absorber or descant packet already has water in it. The oxygen absorbers do absorb a small amount of water. If there is a small amount of water left over in the food it will migrate towards the oxygen packet. When opening a mylar bag of food, if the food is soggy just around the oxygen absorber, but not on the other side of the mylar bag, then it is likely you still had some water left over in the food. This can be particularly pronounced in watermelon.

Several other possible causes of soggy food could be a puncture in the mylar bag. It is possible the of O2 absorber is already used or defective, or that the mylar bag is poor quality or has a plastic window in the bag.

Soggy food could also be a symptom of a bad vacuum pump or a vacuum leak. To determine this, run an ultimate vacuum test, or a leak rate test respectively.

Generally, if you are experiencing this sogginess issue, it can be a good idea to dry the food twice. To do this, dry the food for 24 to 48 hours. Then put the food in a freezer and defrost the chamber, then cool the chamber and start the food again. Run it for another 24 hours of dry cycle. This can be more true during the summer or in hot environments where the freeze dryer is not as able to get as cold. If you realize early that the food is soggy and the food has not spoiled yet, you can save the food by drying the food again. It is impossible to remove to much water from food by freeze drying.