Using a dehydrator for decorated cookies is all the rage these days! But the hows and the whys and the where-to-fors can all get a little confusing. I'm here to help you out.
What is a dehydrator? A dehydrator is an appliance that uses warm, moving air to remove moisture from the food that is placed inside it.
Why IN THE WORLD would I put my cookies in there? For two reasons: One, if you put a moving air source across the top of the icing while it is drying, the icing will dry SHINY. Second, the gently heated air helps the icing dry quicker -- reducing craters, color bleed, and allowing you to move on to the next step in decorating much MUCH faster.
Won't that dry out my cookies? (How long can I leave them in there?) It can, if you leave the cookies in there for too long. As a general rule...if you live in a dry climate limit the time in the dehydrator to 40 minutes total. If you live in a humid environment, you can extend that time up to 2 hours. If you live somewhere VERY humid (you know who you are because the framed pictures on your wall have water damage.) you can leave them in the dehydrator for up to 12 hours. When in doubt -- take them out after 40 minutes.
Can I bag my cookies after 20 minutes in the dehydrator? Probably not. The dehydrator is used mostly to quick-set the top layer of icing. However long it normally takes for your cookies to dry fully...cut that in half if they have spent the recommended amount of time in the dehydrator for your environment. For example, if I live in a dry climate and my cookies normally take 16 hours to fully dry -- I will put them in the dehydrator for 40 minutes total and then let them dry for another 8 hours after I take them out of the dehydrator.
Can I just leave the cookies in the dehydrator to finish drying? Yes. Absolutely. It's a great "safe" environment for the cookies to finish drying in. Just make sure you don't forget about them!
What temperature do I use? The lowest heat setting possible. 95F is ideal but you can go up to 110F without any adverse effects. If you place the temperature too high the icing will ripple or crack from the heat.
Can I dry Royal Icing Transfers in my dehydrator? YES. But, a word of caution -- Use PARCHMENT PAPER instead of wax paper. The wax on the wax paper gets warm and kind of melts into the icing and basically turns into a complete mess of tears and despair. I haven't tried transfers with the dehydrator sheets...but I will! And I'll let you know how that turns out. Depending on the size of the transfer...I usually leave them in there for 3-4 hours.
What kind of dehydrator should I get? This one, my friend, is up to you. I have two different types of dehydrators. I have a top-down Nesco dehydrator and a back-front Excalibur dehydrator.
The first dehydrator I ever owned was this Nesco Snackmaster. At only $60, it's relatively cheap. It's small and super light so you can easily store it on the top shelf of the hall closet. (Hypothetically.) It is a top-down dehydrator, which means that the air blows from the top toward the bottom. So...ONLY on the icing. That means you can leave your cookies in there longer before they start to dry out. The trays are stackable and you can even purchase more trays to add to it. Stacking and un-stacking the trays is definitely a two-hand job. That means you have to take the top off and place it next to the dehydrator and then stack or un-stack. If you try to hold the top in one hand while rearranging the trays...you'll probably end up denting the icing on an edge cookie. Also...some of the trays dip slightly toward the center. If you are flooding a base layer on a cookie larger than 3 inches, you need to let it sit on a completely flat surface before moving it to a dehydrator tray or the icing will start to slide off the cookie toward the center of the tray.
I fell in love with the Excalibur 3900B the second I pulled it out of the box. It holds nearly twice as many cookies as my little Nesco dehydrator. The trays are completely level and slide in and out easily with only one hand. Sometimes if you have larger, heavier cookies on the tray, you need to use both hands to support the plastic frame under the tray so the icing doesn't crack ever so slightly on the surface of the cookies. The front of the dehydrator can be removed completely, which is actually super convenient when you are doing a ton of cookies and pulling the trays in and out over and over again.
One thing I discovered by sad accident, is that the top tray doesn't have as much clearance as the other 8 trays. If you bake thin cookies, you would probably be fine. My cookies are 3/8" thick and if I'm **SUPER** careful, I can do a base layer of icing and gently slide it in without scraping icing off the top of the cookies. But if I pipe any details on top of that layer of icing, I can't put them back in the dehydrator in the top slot.
The only down side to the Excalibur is that the fan blows from the back to the front. That means that it blows on both the ICING and the COOKIE. You do not want your cookies to dry out, so it really limits the amount of time the cookie can spend in the dehydrator before drying out. UNLESS....
Unless...you get some re-usable dehydrator sheets. They are made of thin silicone and are the exact size of the dehydrator trays. Just place them on your trays and put your cookies on top. Like magic... the fan is no longer blowing on your cookie! Just the icing. You can get generic dehydrator sheets for a little over $1 each or you can buy Excalibur brand dehydrator sheets for $11 each. They both fit the dehydrator trays perfectly. The generic brand is slightly thinner, so sometimes the corners flap up a little. I solve this problem by placing a cookie on each of the corners. The dehydrator sheets are either 14" square or 11" square. Make sure you get the right size for the dehydrator you own.
Still not sure about this whole dehydrator thing? More confused than when you started? I also made you a video so you can see these "dehydrator things" in real life.
As promised... links to all my dehydrator-type things:
If you have any other dehydrator questions -- just ask!!! I'd love to answer them for you!! (Especially if it requires an experiment!!)