Keep in mind that the more flavorful the fresh strawberries you start with are, the more delicious the dehydrated version is. Choose locally grown berries and dry a lot of them while they are in peak season—mid-spring to early summer in most places.
- Wash the strawberries.
- Hull the strawberries, cutting off the green parts at the stem end of the fruit. Remove any bad spots.
- Cut small strawberries in half and cut larger ones into quarters.
- Arrange the strawberry pieces on baking sheets cut sides up. Make sure that none of the strawberry pieces are touching. You want good air circulation on all sides of the fruit.
If you prefer, first put a sheet of parchment paper on the baking sheet to prevent sticking. However, as long as you don't position the cut sides of the fruit down on the sheet, they won't stick.
Place the sheets of strawberries in the oven and dry them at 200 F for 3 hours. If your oven is hotter in some spots than others, turn the baking sheets around occasionally so that the strawberries dry evenly.
You won't be completely sure if the strawberry pieces are fully dehydrated until they have cooled. Do you know how cookies crisp up after you take them out of the oven? Same deal with dried fruit. Remove the baking sheets from the oven. Let the strawberries cool at room temperature for 20 minutes.
After the cooling-off period, break one of the pieces of fruit in half. There should be no visible moisture along the surface of the break. The texture should be somewhere between chewy and crisp. If needed, return to the oven for another half-hour and test again until sufficiently dehydrated.
Even after the strawberries are correctly dehydrated, there may still be some residual moisture in the fruit that you can't feel. This shouldn't be enough to prevent the fruit from being safely preserved and mold-free, but you'll have a tastier, better product if you do what is called "conditioning" the dried fruit.
Put the dried, cooled strawberry pieces into glass jars, only filling the jars about two-thirds full. Cover the jars. Shake the jars a couple of times a day for one week. This redistributes the fruit pieces as well as any moisture they may still contain. If any condensation shows up on the sides of the jars, your fruit isn't dried well enough yet, and it needs to go back into the oven at 200 F for another 30 to 60 minutes.
After the dried strawberries are conditioned, store them in airtight containers away from direct light or heat. Use non-plastic food storage containers. It's okay to fully fill the jars at this point: the two-thirds full was just for the conditioning phase when you needed to be able to shake the pieces around. Properly dried strawberries will keep for up to six months under good conditions.