Years ago, when I was new to backpacking, I tried a lot of freeze-dried foods. The other day I sampled some more, to see why they're still on the market.

The answer is I dunno. The stuff is more palatable than it used to be, and sometimes is handy, but except as military or survival rations most freeze-dried foods don't make much sense. As a rule you can do better and cheaper at the supermarket.

In extended high-country backpacking, where every extra ounce translates into ton-miles, the extreme lightness of FDF's can be a blessing. But more often than not high country is dry country, and water must be packed along or hauled up from the valleys after camp is make. It takes about three pounds of water per person to reconstitute a day's food, exclusive of beverages.

And many FDF's come in bulky foil pouches puffed with air or nitrogren. They take up a lot of room in a pack, and while space can be saved by deflating or repackaging, that takes a lot of the convenience out of them. The same amount of time spent selecting and repacking grocery-store goodies will yield more food and flavor for less money.

These conclusions were reached after a weekend's worth of freeze-dried foods (six four-person complete-meal packages plus a fair number of individual items) prepared under camp conditions and shared by two men and two boys. We bought principally Mountain House and Richmoor, the two biggest brands in the field. The total cost was over $100, not including the supplemental standard foods we took along.

One of the big selling points of FDF's -- and they are big sellers -- is that most require no cooking; you just add hot water. But consider what it took to prepare Richmoor's No. 4 Complet Dinner for Four (peas, mashed potatoes, meatballs with brown gravy, banana pudding and fruit punch):

A pot in which to reconstitute the peas with 1 1/2 cups of boiling water, which takes 10 minutes and requires reheating:

A dish with 1/2 cup cold water in which to dissolve the meatball seasoning;

A saucepan in which to soak the meatballs for five minutes in 2 cups of boiling water and then simmer them for five to 10 minutes;

A pot in which to stir the instant mashed potatoes into 3 1/2 cups of boiling water;

A quart container in which to dissolve the punch powder in 4 cups of water;

A bowl in which to stir (and stir and stir) the pudding powder in 2 cups of cold water.

"All you add is water!" the package had said, but the two fellows who prepared the above meal came away with the impression that they had done a fair amount of cooking, using three campstove burners, half a dozen pots, pans and other containers, and about seven pounds of water. The meal would have been a real trial to prepare over a typical one-burner backpack stove with the usual backpack cookware. Washing up took as much water as the cooking.

And what did we get for $8.89, plus tax and the fuel for boiling all that water? Very good peas (after butter was added), pretty good meatballs and mashed potatoes (with more butter) with fair gravy, passable punch and awful banana pudding. The latter still was lumpy after 10 minutes of hard stirring (the package said a couple of minutes would do) and tasted like a bad banana Popsicle.

All in all the meal was okay. But if we had been ravenous backpackers there would not have been enough to satisfy four adults, even if they could have choked down the pudding. A serious hiker, say somebody doing a long stretch of the Appalachian Trial, needs an enormous amount of food. While the portions we found seemed less stingy than I remembered, I would guess that the old rule of "a meal for four serves two " still applies.

And there were only two freeze-dreid items in the package. The meal could have been duplicated for less than half the price, using only freeze-dried peas (which are excellent), with everything else bought at Safeway or done ahead at home. Instant mashed potatoes, gravy and pudding mixes, and beverage powders are sold everywhere, cheap. Meatballs, cooked and then baked fairly dry and wrapped hot, will keep for several days.

The Richmoor No. 3 Breakfast goes for $7.39 at Hudson Bay Outfitters (where we bought our food before we found out that prices for the same items run 10 to 30 percent less at Appalachian Outfitters) but contains only standard supermarket items that can be assembled for half as much: 4 oz. of canned bacon, 11 1/4 oz. of blueberry pancake mix, 6 1/4 oz. of maple syrup mix, 4 1/2 oz. of cocoa mix, and a little cooking oil.

Mountain House's Breakfast No. 4, at $9.20, gives you four (good) freeze-dried sausage patties, plus standard pancake mix, syrup, cooking oil, orangeade and cocoa. The same quantities (with precooked sausage) could be had for a third as much.

So the complete-meal packages are a bad deal. Most experienced backpackers buy only particular items whose convenience or quality justify the cost, such as the peas and freeze-dried ice cream, which if you acquire a taste for it is delicious. There are other mainmeal favorites, such as beef Stroganoff, which can be stretched with instant rice and so forth. A pair of Mountain House freeze-dried ribeye steaks had a strange appearance and texture, but went down fairly well. They should have, at nearly $10 a (reconstituted) pound. The hit of the weekend, not freeze-dried, was Richmoor's wine-flavored smoked beef jerky, which costs $33 a pound.

Freeze-dried fruits and vegetables, with the exception of those great peas, got bad ratings from our crowd, especially Mountain House diced apples. Dry or soaked, they were spit out. We didn't try the carrots because the HBO salesman said he had. Dried fruit from the market costs less, weighs little more, and packs and tastes better. Home-dried fruit "leathers" costs still less and taste better yet.

Even the outstanding FDF's tend to pall fairly quickly; the lunches pall right away. Wide as our selection was, we might have had mutiny in camp the second day had I not been able to produce some venison chops and peanut butter and jelly. If the executives of Mountain House and Richmoor were regularly required to eat the lunches their companies put out, they might stop putting them out. We threw away both versions of chicken salad and hardtack.

Why do people pay such prices for freeze-dried? "Convenience, I guess," one salesman said. "People who are new to camping or backpacking like the whole-meal packages because they don't have to worry about planning meals. After a while they tend to get pretty selective."

Newcomers would do better to pass up the FDF shelves and pick up a few of the backpack cookbooks most outfitters carry in paperback. Used with the skeptical approach appropriate to any cookbook, they can take a lot of the worry out of getting close to nature. Most have sound shopping advice, good meal plans, tips on precooking and packing, and delightful asides that share the hard-won wisdom of people who have spent a lot of time in the outdoors.

Any of the books will pay for itslef in a weekend, if not in a single meal, and you'll eat better.