Freeze drying eggs, milk and cheese at home

Eggs freeze dry well and store for five to ten years, limited by the fat in the yolk rather than anything else. Blend them raw before drying — whole eggs in the shell obviously will not work, and cooked scrambled egg rehydrates worse than raw blended does.

Raw blended is the method

1. Crack and blend until completely uniform. Streaky egg dries unevenly and rehydrates worse.
2. Pour onto lined trays to a depth of 8 to 10 mm. Silicone mats make lifting the dried sheet out possible.
3. Pre-freeze the trays level, or you will get a wedge thick at one end.
4. Run a full cycle. Egg is high moisture; expect the upper end of your machine’s range.
5. Powder it in a blender once dry. Powder stores far more compactly than sheets and rehydrates faster.
6. Seal with an absorber. One 300cc per gallon bag as usual.

Rehydrating

Roughly one tablespoon of powder to two tablespoons of water gives you the equivalent of one egg. Whisk, leave a minute, then cook exactly as you would fresh egg. It scrambles well, works in baking without anyone noticing, and makes a passable omelette.

It does not fry as a whole egg, obviously, and it will not poach. Freeze-dried egg is an ingredient rather than a breakfast.

Milk and dairy

Dairy	Method	Shelf life
Whole milk	Pour to 8–10 mm on mats	2–5 years
Skimmed milk	Same	5–10 years – less fat
Yoghurt	Spread thin; makes crisp drops	2–5 years
Grated cheese	Loose layer	2–5 years
Cream, butter	Do not	Too fatty to work
Ice cream	Pour or scoop on mats	1–2 years; a novelty rather than a store

Why fat is the limit

Sublimation removes water. It does not touch fat, and fat oxidises over time regardless of how good your bag and absorber are. This is why skimmed milk stores twice as long as whole milk, and why cheese — however well sealed — is a two-to-five year food rather than a twenty-five year one.

If you are building a long-term store, dry skimmed milk powder for the deep store and treat whole milk, cheese and yoghurt as a rotating pantry.

The safety note on eggs

Freeze drying does not pasteurise. Raw egg dried raw is still raw egg, with whatever was on it dormant rather than dead. Rehydrate and cook it. Do not use freeze-dried raw egg powder in anything uncooked such as a mousse or a raw cookie dough.