First a little basic science -- from online sources: "At pressures less than 0.00604 atm, therefore, ice does not melt to a liquid as the temperature increases; the solid sublimes directly to water vapor. Sublimation of water at low temperature and pressure can be used to “freeze-dry” foods and beverages. The food or beverage is first cooled to subzero temperatures and placed in a container in which the pressure is maintained below 0.00604 atm. Then, as the temperature is increased, the water sublimes, leaving the dehydrated food (such as that used by backpackers or astronauts) or the powdered beverage (as with freeze-dried coffee)." The partial pressure of water vapor in the atmosphere is about 4.3 mm Hg at the freezing point. To evaporate, it has to barely exceed the atmospheric pressure of 760mm Hg. To do this, either reduce the pressure, or increase the temperature....or add other substances that can evaporate and contribute the rest of the pressure needed. This is where dry ice comes in. It will sublimate (i.e. -- go from solid to gas without first becoming liquid) at -78.5 C. A stream of CO2 flowing over a fixed source of ice will allow the water to sublimate. The key is to have the CO2 "flow." This is where a vacuum with discharge to atmosphere comes in, or a "sink" for the water, such as a dessicant. Clearly, a small blower will not come anywhere close to procucing a suitable low-pressure: It needs to be a pretty good vacuum. Even then, if the source of the CO2 is dry ice, you will need an awful lot of it. You can see why. Divide 760 mm Hg (total pressure) by 4.3 mm Hg and get the ratio 177:1. So if you have 0.1 lb-mole of water in the food (1.8 lb), you need 17,7 lb-mole of dry ice (779 lb). Alternatively, if you have a frost-free refrigerator, you can freeze the food and let the refrigerator do the rest. It will sweep atmospheric air over the food, drawing moisture from it in equilibrium with what is in the air. After a few MONTHS the water in the food will likely all sublime. If you have ever put a tray of water in the freezer, and left it, you would come back to find the tray empty, or mostly so. You can spend your money on freeze-dried foods made by someone else, you can run the refrigerator for months and pay the electric bill, you can buy dry ice and a decent vacuum pump (with other equipment), or you can do air drying or home canning. For emergency foods with long shelf-life and break-resistant containers, commercial freeze-dried foods are the way to go. For everything else, home canning and air drying is cost-effective and pretty healthful. As to the vitamins lost in processig, take supplements separately. By the way, these home vacuum sealers? Yes, they remove oxygen in the air that can otherwise react with food causing flavor and nutrient changes. They don't appreciably change the amount of water so if there are spoilage organisms (there usually are!) that can survive low temperatures in the absence of oxygen (anarobic bacteria), they will continue to grow. One "trick" I've taught is to take steel wool -- maybe a cigarette-sized twist -- and wrap it in a coffee filter. Put it in with the mostly dry food to be preserved, in a very tightly sealed container. The steel wool will react with the water and oxygen inside the container forming rust. The filter paper contains the rust particles so it doesn't mix with the food. As the water and oxygen react, the inside pressure drops. You can see this in a flexible container as it appears "squished." CO2 will not be removed, nor will nitogen or other fixed gases. Since all organisms appear to need SOME water, and that has been converted to hydrated iron oxide, this shouldn't be a problem

FROZEN MIDNIGHT LADY (serves 12) Two 3 oz pkg ladyfingers 1 qt vanilla ice cream 1 qt chocolate ice cream 1 qt coffee ice cream 22 oz fudge ice cream topping 12 oz brickle bits Whipped cream Line sides & bottom of 10" springform pan with split ladyfingers, standing rounded, uncut edges around inside of pan. Drop slightly softened vanilla ice cream by scoopfuls into bottom of pan; smooth ice cream using back of a spoon to form an even layer. Cover ice cream with 1/3 of fudge topping. Sprinkle 1/3 of brickle bits over fudge topping. continue layering next 2 ice cream flavors & toppings as described above. Freeze for at least 24 hours. Garnish with whipped cream before serving.~~Uptown Down South

This is as authentic a recipe for the old-school Italian water ice as you'd want to find. For strawberry, just follow the recipe for the peach one and use the berries, although for raspberry or black cherry, it's better with just the strained juice from the fruits. LEMON WATER ICE 1 quart water 2 cups sugar 3/4 cup lemon juice Grated rind of 1 lemon (no white part) Boil water and sugar together for 5 minutes. Cool. Stir in juice and peel. Pour into shallow bowl and put in freezer. As it starts to freeze, keep stirring the outside crystals into the center and mix in peel. Do this about every half hour. When really slushy, stop and freeze overnight. To serve, you must scrape very thin layers of the slush off the top. I use a big spoon with sharp edges moving it sideways. My notes: This won't turn out right unless you do both the stirring thing and the scraping thing. It really is all about the technique, not the ingredients, which is why you won't get the same results in an ice cream freezer, even though we've tried it. Depending on how many you'll be serving and when, you can divide the ingredients in half for a smaller batch because the syrup starts to congeal after about 2 or 3 days. For all of these, follow the same method as the Lemon Ice, boiling water and sugar together, add other ingredients, then freezing as directed: LEMON-LIME WATER ICE (my personal favorite) Make as above but use 1/2 lemon juice and 1/2 lime juice and equal amounts of lemon and lime peel LIME ICE Make as above using lime juice and peel instead of the lemon. FRESH PEACH WATER ICE 1 cup sugar 2 1/2 cups water 1 1/2 cups peeled and sliced ripe peaches 1 1/2 to 2 tsp. lemon juice Puree peaches in blender with lemon juice. ORANGE WATER ICE 2 cups water 1 cup sugar 1 cup fresh orange juice 1 grated orange rind (no white part) 2 Tbs. fresh lemon juice GRAPE WATER ICE 2/3 cup sugar 1 1/2 cups water 1 cup grape juice 1/4 cup orange juice 2 Tbs. lemon juice

If you have a big chain grocery store in your area, check with them. Publix is one here that has dry ice. In San Diego, I found it at Baskin Robins too. I have found those dry ice directories to be worthless to me in this area. (I routinely have had to buy dry ice for my business). The most I've ever paid for it in the past 10 years is $2.00 lb. Dry ice at Publix is like maybe $1.25 to 1.50 a pound. If you put the ice inside a styrofoam container or box lined with newspaper without breaking it up a bunch you can put a square of it on the bottom of your container and then put in your fruit etc. then put a piece on top of it (the container is something to keep the gases sealed in to make it last longer) a few pounds would work I would think to freeze smaller stuff. Because you could do the quick freeze, then take it out and put in your freezer, then add more stuff to the dry ice. If you break it up into smaller pieces, you will have a harder time fishing the produce out of it when it's done freezing. Plus it's easier for it to burn your hands if you have to handle smaller pieces vs a larger one that you can wrap in newspaper, grab it up, set it down, fish out your produce, etc. When I've shipped lab samples on dry ice, 5 lbs will last up to 2 days during transit as long as it's sealed tight.