Making silicone mats for the 3-tray freeze dryer

Why use silicone mats for Freeze Drying? Some food glues itself to the freeze-dryer trays

See the silicone mat in action.

Here is the silicone mat we used for our small freeze dryer trays.

Before we bought our own freeze dryer, we used my dad’s standard size, 4-tray unit. It’s was older one with the simple, non-touch display with two control knobs. We bought the small, 3-tray unit because it’s just the three of us. We’ve freeze dried leftovers, homemade baby food, random fruit boxes that we bought from our local farmer’s market, and half of our food from Costco.

We love white peaches. We had to run between 5-6 separate cycles to finally finish drying all the slices of white peaches we had. The one step of the process that took longer than anticipated was removing the peach slices from the trays. The peaches were quite ripe, and we blanched them to remove the skin, so they were a bit slimy. After the freeze drying cycle, they were glued to the trays.

Jump down to instruction the video.

This experience was earlier in our freeze-drying adventure, so we didn’t know what we were less “experienced” at everything. We ended up with a bunch of broken white peach bits. That wasn’t completely bad, because they still taste the same when broken :). Besides, we like to break them up into our cold cereal. But, we wanted to have nice-looking freeze-dried fruit that didn’t take forever to remove from the trays.

Simple solution

To solve the problem of food sticking (per the recommendation of others), we cut sheets of silicone to completely cover the bottom of the trays. The silicone easily peels up, releasing the food with very little effort.

Here’s the result…we didn’t have the silicone sheets for the white peaches, but here’s our video of me removing a batch of strawberry slices from a tray with one of the silicone mats:

“Making” the silicone mats for the trays

First, you’ll need to find the right mat that you can cut up. There are only a couple requirements:

  • Must be real silicone
  • Must withstand very low and high temperatures
  • Obvious one – should fit your trays

The process is simple

  1. Measure your freeze dryer trays
  2. Buy the cheapest mat that will fit your trays
  3. Cut the mats to size
  4. Trim the corners for the tray radius

My dad used these mats:

The 24″ x 36″ mat was the best fit for his standard size freeze dryer and also for his larger, 5-tray freeze dryer.

After measuring our small trays

With 3 trays that are 7″ x 13 1/4″, we needed a mat that was at least 13 1/4″ x 21″.

We found these mats on Amazon:

My wife has wanted a silicone rolling mat like this for a while, so we bought two.

The mat unboxed and rolled out

Perfect fit for the 3 trays…with not too much waste

Sewing tools worked perfectly for cutting these

Now, to cut the corners

One tray completely finished

A close-up of the tray corners

Not too many scraps

There’s got to be somewhere I can use these scraps for anti-slip?

4 thoughts on “Making silicone mats for the 3-tray freeze dryer

  1. Hello! I am wondering if your silicone mats are good for the really low temps? I know Harvest Right’s mats are good to -50 degrees F. I saw on Amazon that the ones you have go to “only” -30 degrees F. So wondering how they are for you and if you think they are safe to lower temps than advertised. Thanks so much for this great tutorial.

    Reply

    1. We haven’t had any issue with them. We use them almost every time we freeze dry liquids or yogurts. We’ve done dozens and dozens of cycles with them :). What you really care about with the silicone mats is that they are 100% silicone. Make sure to avoid the mixed silicone products.

      Reply

  2. Just a note, the mats you used have reenforced fiberglass in them, so when you cut them you exposed your food to that fiberglass. If they were 100% silicone that wouldn’t be an issue, but the fiberglass makes this a bad idea. I’m not sure if they have changed since you posted in 2017, but the link you have posted takes you to the same looking product that includes fiberglass.

    Reply

    1. I saw a similar comment on the YouTube video. It’s definitely something to consider. Here’s the comment I made:

      “I’ve been using these mats since (checks publish date of video) mid-2017. But I’ve now seen a couple comments warning about cutting them as well. I had to take another look.

      Here’s a pic of the uncut/unmodified mat next to the three I cut. https://www.familycanning.com/wp-content/uploads/2021/03/silicone-mat-cut-vs-uncut.jpg. Interestingly, my uncut mat (the one rolled up), which we have used weekly in our kitchen for the past few years, shows some fraying fiber. Not ideal. The mats I cut are actually in better shape, but they still show some fiber fraying.

      It looks like the factory cut marks go right through the fiberglass mesh; that’s unfortunate. I guess we should label this project a “use at your own risk?”

      Anyways, back to see if there is a better, more economic option. Live and learn.”

      Reply

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