How it is made
From raw beef liver to a dry treat, step by step
Updated
How is freeze-dried liver made? Raw beef liver is frozen solid, then placed under a vacuum, where the ice leaves the liver as vapor instead of melting. What remains is dry, light liver with almost no water in it, never cooked. Ours is done in small batches in Malvern, Pennsylvania, from Pennsylvania farm beef.
Where does the liver start?
On a farm in Pennsylvania. The beef liver we use comes from a Pennsylvania farm, and that is as specific as we get. It arrives raw, and it stays raw through everything that follows.
From there it goes to Malvern, Pennsylvania, where Sniff and Shift freeze-dries it in small batches, bags it and ships it. One ingredient goes in and one ingredient comes out. There is no step where anything is added, and the product data states no preservatives, fillers or additives. Our about page tells the longer story of the people behind the bag.
What happens inside a freeze-dryer?
Two things, in order. First the liver is frozen hard, so the water inside it becomes ice and the structure of the piece is fixed in place. Then the chamber is pumped down to a vacuum. At that low pressure the ice does not melt into water. It turns straight to vapor and is drawn out of the chamber, leaving the solids behind.
Because the water leaves as vapor from a frozen piece, the piece keeps its shape instead of shrinking into a hard nugget. That is why a freeze-dried piece looks like the original chunk of liver and weighs so little. Our label lists moisture at a maximum of 10 percent, which is the ceiling for what is left when the cycle ends. No warm air is involved at any point, and that is the main difference from a dehydrator.
Is freeze-dried liver cooked at any point?
Ours is not. The liver goes into the freeze dryer raw and comes out raw, with the water gone and no cooking step anywhere in the process. Freeze-drying is a drying method, not a cooking method, and the two should not be confused when you read a bag.
That matters for how you treat the bag. A raw product is handled like raw meat, which is why the back label says to wash hands after handling. Some other freeze-dried treats are cooked before drying, so if raw matters to you one way or the other, the label on any bag is the place to look. Our raw vs freeze-dried guide compares all four forms of liver, from fresh raw to freeze-dried, in one table.
How does it end up in a sealed bag?
Once a batch comes out dry it is bagged by Sniff and Shift in Malvern. The bag has a zip so you can reseal it, and the back label carries the storage line: "Store in a cool, dry place. Reseal after opening for maximum freshness." The best-by date printed on the bag is set one year from the production date.
We fill 1.5 ounce, 3 ounce and 6 ounce bags, and the liver inside is the same in each. The bags ship from Malvern as well, so the liver stays in Pennsylvania from the farm to the shipping box. The beef liver page shows the front and back of the bag, with the full label panel.
Can you freeze-dry liver at home?
You can, if you own a home freeze dryer, and people do. The machine does the same two steps of freezing and then pulling a vacuum, at kitchen counter scale. We are not going to hand you a recipe with times, because we do not know your machine or your liver, and a bad guess from us helps nobody.
What we will say is that raw liver at home is raw meat at home. The FDA's page on raw pet food diets covers handling raw pet food in the house, for the people as much as the dog, and it is worth a read before you start. The bag we sell exists for people who want the result without the equipment or the cleanup.
Questions
How is freeze-drying different from dehydrating?
A dehydrator moves warm air over food for hours and dries it from the outside in, so the piece shrinks and firms up. A freeze dryer freezes the food first and pulls the water out as vapor under a vacuum, so the piece keeps its shape and stays light. The raw vs freeze-dried guide linked above compares the forms in detail.
Why does freeze-dried liver weigh so little?
Because most of its weight was water, and the water is gone. Raw liver is mostly water by weight, and freeze-drying removes nearly all of it, down to the label's maximum of 10 percent moisture. What is left is the solid part of the liver, which is why a full bag feels oddly light.
Is anything added during freeze-drying?
No. Freeze-drying is a physical process of cold and then vacuum, and nothing goes into the chamber with the liver. The product data for our bag states no preservatives, fillers or additives, and the ingredient list is beef liver alone. The smell and the pale tan color are the liver's own.
Where is your liver freeze-dried?
In Malvern, Pennsylvania, in small batches, by Sniff and Shift, which also bags and ships it. The liver itself comes from a Pennsylvania farm. We do not name the farm, and a Pennsylvania farm is as far as we go. That keeps the whole chain inside one state, from farm to bag.
Do I need to rehydrate it before feeding?
No. The bag says "Feed as a treat, reward, or topper," and it says nothing about adding water. Dogs take the pieces dry, and the dry snap is part of what makes them work as a training reward. The same label asks you to provide fresh drinking water, which is about the dog rather than the treat.
Why is the bag resealable?
Because the liver is dry, and dry food takes moisture back from the air once the seal is broken. The zip lets you push the air out and close the bag after each use, which is what the label means by "Reseal after opening for maximum freshness." Use an open bag within 30 days.