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

I got the Nesco Encore Dehydrator for my birthday this year. I LOVE it. It dries my garden herbs in a very short amount of time. I rinse my herbs first and then spin them dry in a salad spinner. Place them on the dehydrator tray set at 125 degrees (supposed to be 95 degrees but I use the higher degree for time expedience and have not seen any problems so far). My oregano does especially well. Chives lost all of their flavor - even at the lower setting. Before the dehydrator I hung my herbs in my china closet to dry - worked well but took a long time. PS. Made beef jerky too - fabulous! Here is a link that might be useful: Nesco® American Harvest® Snackmaster® Encore⢠Dehydrator and Jerky Maker

Many of the leafy herbs will be limp on thawing - parsley, coriander, dill leaf, basil etc - but they can be used in recipes. They retain their flavour, but not their looks, so aren't much good for garnishes and the like. You don't have to freeze them in water, though for herbs like chives, this is a handy way of doing it - just pop the ice cube into your stew, or for things like lemon balm, into your summer punch! I just chop them up and put them in a plastic bag or a plastic container, pressing them down into a flat pancake. It's easy then just to break off pieces of suitable size, without having to get out the hammer and chisel to break up a mountain or solid rock! You can make layers by putting some plastic wrap between. Or you can put different herbs into plastic sandwich bags which you then label, and put the bags in layers inside a larger suitable container. That way you can keep all your herbs together and they don't get lost in the freezer. You CAN dry any herb, but some lose their flavour on drying (basil, chives, oregano). Some flavours are intensified on drying (rosemary, bay). You need to experiment with small amounts to see which you prefer to suit your own taste buds. Remember, if drying, that the smaller the particles (powder), the shorter the shelf-life. Also remember to keep dried herbs well away from heat, light, moisture and bugs - in airtight containers (ie NOT near the stove!!).

I have always had both refrigerated and dried. I make the starter batch, and spread a little onto some plastic wrap. Its allowed to air dry for about 2 days. By then it crumbles easily. I simply place in a small plastic bag and its fine for almost forever, if stored in the fridge. You MUST create the starter from just water, flour, and the orignal sourdough culture. Do not add salt, sugar or anything else to the culture!! Every time I make a batch of sourdough, I mix my jarred, refrigerated one with flour and water to give me a stiff batter, almost a sticky dough, as well as adding a little of the dried. I keep the dried ones in the fridge too. I have several, one for rye, one, my grandfather used 100 years ago, and one with a more recent (30+ year old) sourdough culture from San Francisco. All three are viable and will start 'working' within 4 hours. The water I use has no chlorine, so bottled might help prolong the cultures. I do have a new one pound bag of regular yeast, and its compressed and granulated. I store it in the freezer, unopened. Once it is opened, it goes into a canning jar with air tight lid, then back into the freezer again. Everything mentioned in the King Arthur descriptive above is exactly what I do. I don't mind smelling top of the starter liquid in the fridge, as its 'hooch' (booze) like another person mentioned. There is also another recent post I made that covers the same issues of keeping a sourdough culture alive and well. I don't even bother to feed mine, and it could be sitting in the fridge 6+ months at a time, with no ill effects.