What Not to Dehydrate

While many foods are suitable for dehydration, there are certain types of foods that are either not recommended for dehydration or require special precautions due to safety concerns or undesirable results when dehydrated. Here are some foods you should generally avoid or use caution with when considering dehydration:

1. High-Fat Foods: Foods with a high fat content, such as avocados and fatty cuts of meat, are not suitable for dehydration. The fat can become rancid during the drying process.
2. Dairy Products: Most dairy products, including milk, yogurt, and soft cheeses, are not suitable for dehydration due to their high moisture content and risk of spoilage. However, hard cheeses can be dehydrated to make cheese powder or crisps.
3. Eggs: Dehydrating whole eggs or egg yolks can be challenging and may result in undesirable textures and flavors. It's better to use commercially prepared powdered eggs for convenience. Can also grow bacteria if done at the wrong temperature. 
4. Foods with High Sugar Content: Foods with extremely high sugar content, like jam or jelly, can become sticky and difficult to handle when dehydrated. They may also attract insects.
5. Fruits and Vegetables with High Water Content: Some fruits and vegetables, like watermelon and cucumber, have such high water content that they are impractical to dehydrate effectively. They will not yield good results and may take an exceptionally long time to dry.
6. Raw Potatoes: Raw potatoes contain enzymes that can lead to discoloration when dehydrated. It's best to blanch or precook them before dehydrating.
7. Mushrooms (Raw): While it's safe to dehydrate mushrooms, some people find the texture and flavor of raw dehydrated mushrooms unpalatable. You may prefer to cook them briefly before dehydrating.
8. Leafy Greens: Leafy greens like lettuce and spinach are not commonly dehydrated due to their high water content and fragile texture. They may not rehydrate well and can become bitter.
9. Foods with Mold or Spoilage: Never dehydrate foods that are moldy or spoiled, as this won't make them safe to consume. Dehydrating won't remove toxins or contaminants.
10. Highly Perishable Foods: Foods that spoil quickly, such as seafood and unpreserved meats, are not suitable for dehydration unless you have the proper equipment for making products like jerky.