How Freeze Dried Dog Treats Are Made

October 16, 2026

Freeze drying is two steps: freeze the food solid, then pull the ice out as vapor under a vacuum, without ever melting it. What is left is the same shape as the raw piece, with the water gone.

Every other fact about a freeze dried treat, from the weight in your hand to the crunch to the way the bag has to be closed, follows from those two steps. The rest of this page goes through them in order.

Freezing, then a vacuum

The food goes in raw or cooked, cut to size, and is frozen hard first. Cold alone does not dry anything, since a frozen piece still holds all its water as ice. The drying comes from the second step, when the frozen trays go into a sealed chamber and a pump pulls the air out.

In a vacuum, ice behaves differently. At normal pressure, warming ice makes water: it melts, runs and soaks the piece. At very low pressure it skips the liquid stage altogether and goes straight to vapor. The chamber is then warmed gently, which supplies the energy for that change without letting the food thaw.

Size matters at this stage. Vapor has to work its way out through the dry outer layer of the piece, so a thick chunk takes longer than a thin slice, and a cube twice as wide takes far longer. That is one reason freeze dried treats are mostly small: cubes, thin slices, and whole small animals such as minnows.

Sublimation in plain words

The word for ice turning straight to vapor is sublimation. You have seen a small version of it in a freezer, where an ice cube left for weeks shrinks without ever making a puddle. Freeze drying runs the same process faster, on purpose, with a pump and a heated shelf.

The vapor does not stay in the chamber. It is drawn onto a very cold surface called a condenser, where it freezes again as frost, and a separate stage at the end dries off the last of the moisture that is bound into the food. A batch takes many hours, and the size of the chamber sets how much goes in, which is why freeze drying is done in batches.

Why the pieces keep their shape

Water leaves as vapor, never as a liquid flowing out of the piece, so nothing collapses. The ice crystals that filled the food leave small pores behind. A cube of beef heart that goes in at one size comes out at about the same size, lighter and slightly spongy, with the grain of the meat still visible.

The weight difference is the part worth checking against a number. USDA FoodData Central lists raw beef heart at about 77 grams of water per 100 grams, a little over three quarters of its weight. Take that water out and a pound of raw heart becomes roughly a quarter pound of treat. By that arithmetic a 3 ounce bag of freeze dried beef heart started as about 13 ounces of raw heart, a little less if some water stays in.

The porous texture also explains the crunch, and why the pieces take water back quickly when they meet it. That is useful when you want it, and it is the subject of how to rehydrate freeze dried treats.

You can judge a dried piece with your hands. A finished piece is light for its size, dry to the touch and crisp, and it snaps or crumbles instead of bending. A piece that feels cool, tacky or slightly damp in the middle either was not finished or has taken on moisture since, and the bag is the first place to look.

What the bag has to do

A freeze dried piece is dry by design and takes moisture from the air. The bag has one job: keep the air out. A good bag is thick, sealed at the factory and closes tightly again after you open it. If a bag holds a small packet marked oxygen absorber, the packet stays in the bag and out of the dog.

That is the trade off. A freeze dried treat is light and crunchy, and it picks up moisture once the bag is open, at which point it goes soft and loses what made it a freeze dried treat. Press the air out, close the bag fully and follow the storage line printed on the label. Freeze dried compared with air dried, dehydrated and baked sets out how the other methods handle the same problem.

The house line of Sniff and Shift is freeze dried in small batches in Malvern, Pennsylvania, and the label on each bag says what is inside and how to keep it.

What freeze drying does not do

It does not cook anything. A raw piece goes in raw and comes out raw, with the water removed and nothing else changed. For that reason a freeze dried treat made from raw meat is handled like any raw product, and the raw feeding notice on this site lays out the routine. The question of what counts as raw gets its own page in whether freeze dried dog treats are raw.

It does not improve an ingredient either. The piece that comes out is the piece that went in, only drier, so a label that lists one ingredient is describing the piece directly, and a label with ten is describing ten. Read the label, and compare what you find across the freeze dried dog treats on the site.

Nor does it add anything. The machine creates no flavor and applies no coating, so whatever the treat smells like comes from the food that went in. If a bag smells of something the label does not list, that is worth a question to the maker, which is a call or an email away.

Common questions

How long does freeze drying take?

Many hours for a batch, because the ice has to leave slowly under low pressure. The machine sets the pace, which is why batch size is limited.

Is freeze drying the same as dehydrating?

No. A dehydrator dries food with warm moving air, and the piece shrinks and hardens. Freeze drying removes ice under a vacuum, and the piece keeps its size.

Why do freeze dried treats weigh so little?

Raw meat is mostly water by weight, and freeze drying removes it. USDA FoodData Central lists raw beef heart at about 77 grams of water per 100 grams.