YOU PUSH through the heat toward home after a long day at the office, looking forward to sitting down, taking your shoes off and relaxing, when you remember you invited people to stop by for a drink before dinner. What to serve them?

A seemingly simple solution is to provide a selection of interesting olives (not the ubiquitous canned "ripe" or pimiento-stuffed types) and plump, freshly roasted nuts. But a good nut is hard to find.

We've combed the area to find Washington's most interesting selection of nuts and olives. There were more good olives than nuts. After two serious blind tastings our tasters found strong differences between acceptable and unacceptable goods. Nuts

To make a fair comparison among the stores in the Washington area which carry nuts, we bought the same two kinds at each one. We chose roasted and salted peanuts and cashews. As soon as we assembled all of our purchases it was obvious we were going to find differences among the flavors because of the variance in color and shape.

Nuts become rancid easily, especially if they are not stored properly, which may account for the poor-quality nuts from some stores. In the shell, nuts will keep for about one year if stored in a cool, dry place and much longer if refrigerated.

If nuts are shriveled, nuts are stale; but not all stale nuts will shrivel. To keep shelled nuts from going stale at home, store in an airtight container in a cool, dry place where they will keep about four months. Of course, they will stay fresh much longer in the refrigerator. Hermetically sealed tins will keep indefinitely, but nuts in a sealed plastic container are likely to go bad eventually.

Blanched nuts have the inner skins removed.This skin contains flavor and nutritive value, but when pristine appearance is important you may want to have nuts without it.

You can buy raw nuts and toast $&(WORD ILLEGIBLE $&)See SHOPPER, G8, Col. 2 > $&(WORD ILLEGIBLE $&)SHOPPER, From G1 > them yourself by placing them in a single layer on an ungreased baking sheet in a preheated 350-degree oven for about 15 minutes. They burn quickly, so watch carefully. Then store them in an airtight container.

You can also deep-fry nuts, which is the way they are "roasted" in many local stores. Fry in vegetable oil at about 360 degrees for 2 to 3 minutes and drain well. Peanuts

Yes Food Shop, 1015 Wisconsin Ave. NW. "Crunchy, flavorful peanut; good ball park fare; far too dry for what should be an oily nut." ($1.03 per pound)

The Nut Shell, Mazza Gallerie. All nuts here are roasted on the premises. "Dry, bland, understated; too raw; good crunch, flavor not so good; pale and small." ($1.98 per pound)

Munchees, Lakeforest Mall, Gaithersburg. "Tastes like the ground, off taste, odd aftertaste, stale, mealy, bitter, astringent." ($1.45 per pound)

Barcelona Nut Shop, 7328 Carroll Ave., Takoma Park. This is mainly a wholesale operation, supplying nuts to a great many shops and stores throughout the Washington area. You may buy retail from their large selection at this location. Even though some of the other nuts we tasted may have come from Barcelona as well, we still detected differences among them."Good crunch, tastes a little musty, bitter with unpleasant aftertaste; just salty enough." ($1.20 per pound)

Peanuts 'n Parties, 11419 Georgia Ave., Wheaton. This store also roasts its own nuts. "Okay, not too greasy but not enough taste, yellow-green pale color, raw tasting." ($1.59 per pound)

Kemp's Nuts at Woodward and Lothrop stores. "Tasty, a rich aftertaste, fat-looking, great crunch, good oil peanut flavor, garlic undertone." ($2.90 per pound)

Androus Nut Shop, 1214 G St. NW. This shop is located inside an enormous G. C. Murphy store. Androus and the shop in the Mazza Gallerie have the same owner; nuts are roasted on the premises here as well. "Uneven sizes, medium crunch, off flavor, dry and musty." ($2.15 per pound)

Planter's, purchased from Safeway. "Very flavorful, middle range peanut; good crunch." (45 cents for 4 1/2-ounce plastic package, or $1.60 per pound) Cashews

Yes. "Buttery flavor; a bit bland; moist." ($3.90 per pound)

The Nut Shell. "Nice looking, not as rich tasting, but with a deep flavor; soft, not crunchy." ( $4 per pound for broken cashews; $4.60 per pound for split cashews; $5.80 per pound for whole nuts)

Munchees. "Nice flavor, metallic cast, dry." ($3.75 per pound for split cashews; $5.99 per pound for whole nuts)

Barcelona. "Too salty, somewhat stale, surprising lack of cashew flavor." ($3.50 per pound)

Peanuts 'n Parties. "Wishy-washy, flat flavor, dull." ($4.19 per pound for broken cashews; $4.49 per pound for cashew butts; $5.19 per pound for medium cashews; $5.49 per pound for jumbos)

Kemp's. "Big nut, fat, rich, chewy, very buttery." ($7.90 per pound)

Androus. "Extremely pale; odd but acceptable taste; good crunch; excellent, oily flavor." ($5.80 per pound) Olives

Columbia Deli and Groceries, 1778 Columbia Rd. NW, offers Sicilian Green olives, which are spicy and dense, and Greek Black olives, which are meaty, strong and almost bitter. Both are $1.89 per pound.

Thomas Market, 1650 University Blvd., Wheaton. This store yielded the largest selection of olives; almost all imported from Greece. Prices here range from $1.20 to $1.60 per pound. Throubes "Hios": "mealy, salty, dry"; not a favorite. Moroccan oil-cured: "off-flavor, mealy." Calamata: "firm, a bit dry; can sink your teeth into these." Royal Vasilikos: "strong pickled flavor, meaty, salty." Big Green Cracked: "toothy, rubbery." Small Green Cracked: "toothy, with a metallic taste." Black: "very soft flesh but pleasant flavor; subtle."

Mancuso's Foods, 2208 Rhode Island Ave. NE, stocks a green olive which they crack and marinate themselves. It has a firm flesh and an attractive peppery marinade. Their Black Greek olives have a distinctive mild flavor. The dried Italian olives at this store have almost no taste and a dry texture. All olives here cost $1.49 per pound.

Francesca's Italian Gourmet Deli, 7653 Old Georgetown Rd., Bethesda, sells three types of bulk olives which we tried: a big, fleshy and pleasant Cracked Green olive; a Marinated Cracked Green type which is peppery and vinegary, and a small Black olive with a pickled flavor. These olives cost from $1.75 to $2.19 per pound.

The French Market, 1632 Wisconsin Ave. NW, sells two types of bulk olives. We tasted the tiny French variety (which sells for $3.50 per pound) and found a big pit surrounded by one small morsel of salty flesh. This market also carries a large selection of French olives in jars. We sampled the Pikarome a la Grecque, a dried Greek-style olive with a salty, fruity, mild flavor, 7-ounce jar costs $2.10. The Barral Nicoise olives displayed a sweeter, berry-like flavor with a tinge of cloves; the cost is $2.90 for 6.5 ounces. The third jar we tasted held Bocquet Nicoise olives, which were spicy and soft; they cost $2.60 for a 4 3/4-ounce jar. Bloomingdale's also carries these brands of olives.

Georgetown Coffee, Tea and Spice, 1328 Wisconsin Ave. NW. This store carries the Krinos Greek brand of olives, of which we tasted three varieties. Krinos' Calamata olives turned out to be the most popular of the tasting, with panelists often going back for more. They are bathed in a vinegar and oil-like brine which creates a mildly spicy flavor.The Alfonso olives were hard to like with an overwhelming medicinal and bitter taste. Both of the above olives sell for $2.79 for an 11-ounce jar. The Cracked Green olives, which cost $2.49 for 11 ounces, are small and exceedingly salty.

El Progresso, 2158 Mt. Pleasant Rd., NW, also sells Alfonso olives which were just as hard to like as the Krinos Alfonso we had eaten, leading us to believe the olive variety was responsible. Here they cost $1.89 per pound.

Mangialardo & Sons Grocery, 1317 Pennsylvania Ave., SE. Bulk olives cost $1.50 per pound. Their Greek Black taste extremely salty and bitter. The Italian Green have a firm and pleasant pickled taste.

Italian Gourmet, 505 Maple Ave. West, Vienna, provides a variety of bulk olives, the cost of which run from $2 to $2.50 per pound. Moroccan Dried: "extremely salty, I can't take it." Moroccan Seasoned: "sour, strong flavor." Pitted Moroccan and Sicilian: "very herby taste, good flavor." Greek: "very soft, mildly sharp." Sicilian: "very sour and dry; closest to taste of just-picked olives."

The Georgetown Wine & Food Co., 1015 Wisconsin Ave., NW carries the only American pickled olives we found. They are made in California from the Mission olive in a dried Greek style. Their flavor is strong and dry, pleasantly pickled; the price is $1.99 per pound.