How do I freeze dry something?!


Question:

How do I freeze dry something?

I want to make my own fish food for my piranhas. I'm going to cut it into wafers or cubes or something. I'm set on doing this so I really need to know how to freeze dry.

Additional Details

1 month ago
I don't want to have to store the finished product in my freezer, that's why I want to freeze dry so I can store it by my aquarium with out it going bad.

Won't freeze drying something give it freezer burn?

1 month ago
Would it just be better to put it in the oven set on the dry setting?


Answers:
1 month ago
I don't want to have to store the finished product in my freezer, that's why I want to freeze dry so I can store it by my aquarium with out it going bad.

Won't freeze drying something give it freezer burn?

1 month ago
Would it just be better to put it in the oven set on the dry setting?

I found this on a site.. not sure it'll work with fish food though...

"Freeze Drying At Home

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You probably don't have a good vacuum chamber at home, but you almost certainly have a refrigerator. If you don't mind waiting a week you can experiment with freeze drying at home using your freezer.

For this experiment you will need a tray, preferably one that is perforated. If you have something like a cake-cooling rack or a metal mesh tray that is perfect. You can use a cookie sheet or a plate if that is all that you have, but the experiment will take longer.

Now you will need something to freeze dry. Three good candidates are apples, potatoes and carrots (Apples have the advantage that they taste OK in their freeze-dried state). With a knife, cut your apple, potato and/or carrot as thin as you can (try all three if you have them...). Paper thin if you can do it. The thinner you cut, the less time the experiment will take. Then arrange your slices on your rack or tray and put them in the freezer. You want to do this fairly quickly, or your potato and/or apple slices will discolor.

In half an hour look in on your experiment. The slices should be frozen solid.

Over the next week look in on your slices. What will happen is that the water in the slices will sublimate away. That is the water in the slices will convert straight from solid water to water vapor, never going through the liquid state (this is the same thing that mothballs do, going straight from a solid to a gaseous state - mothballs are the only thing in a normal person's life that sublimate naturally). After a week or so (depending on how cold your freezer is and how thick the slices are) your slices will be completely dry. To test apple or potato slices for complete drying, take one slice out and let it thaw. It will turn black almost immediately if it is not completely dry.

When all of the slices are completely dry, what you have is freeze-dried apples, potatoes and carrots. You can "reconstitute" them by putting the slices in a cup or bowl and adding a little boiling water (or add cold water and microwave.) Apples you can eat in their dried state, or you can reconstitute. What you will notice is that the reconstituted vegetables look and taste pretty much like the original! That is why freeze drying is a popular preservation technique."

Source(s):
http://www.thefarm.org/charities/i4at/su...

If you have a sealer machine for that purpose, use it. But I assume you don't, so you can do it the old-fashion way: Get the plastic ziplock bag with the food inside it and zip it until it's almost closed. Then place a straw inside the bag and suck all of the air out. then close the bag completely. Then the food is ready to be stored in the freezer.

buy some dry ice and put in a cooler then use to freeze your foods!

I would advise aginst freeze drying and instead suggest flash freezing. Flash freezing is freezing something very quick to temperatures below normal freezing. The quickness of the process will prevent damage to the fish food.

Basically all you will need is an ice chest and some dry ice.

Place the dry ice in the cooler and then place the food you want frozen in a thin baggie in the dry ice. Close the lid, but don't lock it!!!

After an hour or so pull the baggie out, transfer the food to a normal freezer bag (squeeze out excess air) and you are done.

In the commercial freeze drying process, food is flash frozen then put in a high-powered vacuum to extract the moisture as ice, then heated to finish driving off the water, leaving behind a dry product.
If you look at food that's been stored in your home deep freeze for too long, you'll see ice crystals in the packaging; freezer burn is kindof like mini freeze drying.

Outside of small experiments, you'd have to get commercial equipment to do any mass quantity of freeze drying. But small, thin food items are doable at home.




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