Prep the rhubarb: Rinse stalks well and pat dry. Trim the ends. Use a sharp knife or mandoline to slice long, thin strips—about 1/8 to 1/4 inch thick and 6–10 inches long. Aim for even thickness for consistent drying.

Sweeten lightly: In a large bowl, toss the strips with sugar, lemon juice, vanilla (if using), and a pinch of salt. Let sit for 10–15 minutes. The sugar will draw out some moisture and help the strips relax.

Optional pre-soften: If your rhubarb is very thick or fibrous, blanch strips in simmering water for 30–45 seconds, then transfer to an ice bath. Pat very dry before proceeding. This step helps ensure even texture.

Set up your dehydrator: Line trays with nonstick mesh or parchment. Arrange strips in a single layer without overlapping. Sprinkle with a pinch of cinnamon, ginger, or zest if you like.

Dehydrate: Dry at 125–135°F (52–57°C) for 5–8 hours. Flip halfway through if the strips curl. Time varies by thickness, humidity, and machine. They’re done when pliable, leathery, and no longer tacky on the surface.

Oven method (alternative): Heat oven to its lowest setting (usually 150–175°F / 65–80°C). Line baking sheets with parchment or silicone mats. Arrange strips in a single layer. Prop the oven door slightly open with a wooden spoon for airflow. Dry 3–5 hours, rotating pans as needed, until leathery and evenly dry.

Condition the strips: Let cool completely. Place dried strips in a large jar or container, loosely packed. Store at room temperature for 3–5 days, shaking the jar daily. If condensation appears, return strips to the dehydrator or oven for another 30–60 minutes. This step evens out moisture to prevent mold.

Cut or roll: Keep long strips as-is, or cut into shorter lengths. You can also roll them into spirals for on-the-go snacking.