DR. BREW brews his lager strictly for the taste of it. Rich, dark and aromatic, it has tiny, creamy bubbles creating a perfect half-inch head that looks thick enough to eat with a spoon. Tiny bubbles are a sign of freshness, he says, and the key to great-tasting beer. Since he can't consistently buy fresh, rich lager in the United States, this beer perfectionist brews his own.

The batch, his own, self-proclaimed "Legendary Number 65," is bitter-sharp. Serving temperature is 55 degrees and it is poured from a recycled champagne bottle that has a designer gray and black cap. He brews it low in alcohol (3 to 4 percent) just so he can drink more--up to two or three bottles a night. This, his favorite recipe, is only one of 85 he's created since his record-keeping began some four years ago.

"Actually I've been fermenting various things since I was 9 years old," says 32-year-old Phil Angerhofer (his CB handle is Dr. Brew). The first attempt was in South Dakota with choke cherry wine, he shudders. "I made one quart, snuck out and drank it with a friend under a bridge and got totally smashed." Regardless of the rugged hangover that followed, it was the beginning of what he expects to be a lifelong hobby.

But it wasn't until legislation passed in 1978 making home brewing legal that he was allowed to bring his expertise out into the limelight, where fellow brewers have proclaimed him one of Washington's best. Today there are upward of a million home brewers, many forming brewing clubs, such as his local club "Brewers United for Real Potables," (BURP) formed in August 1981.

Legalization also has brought a surge in supply houses and has made equipment much easier to obtain. There are vast improvements in the variety of ingredients available, turning brewing into an art form for people like Angerhofer. While home brewers can't sell their product, they are allowed to produce up to 200 gallons per year--100 for the head of the household and up to 100 more if there are other adults in residence.

His favorites are English ales, lager, stout and porters. The flavor differences are tremendous, he says, donning a plastic red-white-and-blue John Bull (the English equivalent of John Doe) Brewery apron. English ale--a light beer, bitter-dry and full-bodied--ranges in color from golden to amber. Lager is a "bottom fermenting" beer, with varying bitterness and generally lighter in body than ales. Stout is a heavy, dark ale with the color and taste of heavily roasted barley and full bitter taste. Porters, also very dark, have the full bitter taste of stout without the heavy burned malt taste.

"I can brew beers that I cannot buy fresh in this country," Angerhofer says. Most commercial American beers aren't bitter or malty enough and are overcarbonated for his tastes. Imports, he says, sit on the docks "for who knows how long" and are subject to wide temperature variations before they get to the store.

Freshness, he reiterates, is the key to a good-tasting beer. "It is a living thing and has a finite shelf life." After a few months in temperature-controlled storage even his own home brew begins to sour. While most commercial brewers use preservatives, many pull it from the shelves after 90 days.

"In England they brew for economics," he says, adding that one in every seven adults brews his own beer or wine there because of prohibitive taxes. "But Americans brew for taste. At least that's my motivation."

Though he sometimes brews from scratch, this night in his Beltsville home he brews a traditional cidery ale--uncomplicated for beginners. There are four basic ingredients in beer, he explains--malt, hops, yeast and water--and it can cost anywhere from $7 to $20 to make each five-gallon batch, depending on the availability of ingredients chosen. Some home and commercial brewers also add rice or corn to lighten them, but this is contrary to the absolute purist's tastes, he says.

Malt, he explains, is wheat or barley grains softened in water until they sprout. They are then roasted to determine the color and flavor of the brew. Higher temperatures and longer roasting times produce darker, denser malts and dark, dense brew. The grains are then cracked and water is added to form a thick porridge. This mixture, called mash, is held at 150 degrees for an hour while the enzymes formed back during the sprouting stage act on starches, converting them into sugars.

Hops, the female flowers of the hops plant, are dried or pelletized and added to the malt for their bitter flavor and aroma and act as a preservative. Plain tap water makes up the bulk of the brew. After the mash is boiled, yeast is added to the cooled mixture. Yeast reacts with the sugars in the brew, converting the mixture into alcohol during the fermenting stage.

He lines the burner of the gas stove with aluminum foil to prevent scorching and fills a stainless steel, three-gallon pot halfway with water, turning the flame up high underneath.

He opens a three-pound can of hopped malt extract, dark and thick, similar to caramel in its sweetness and texture. It's called hopped malt because dried hops already have been cooked into the mixture to add a bitter characteristic.

When the water comes to a full rolling boil, he dribbles the hopped malt into the boiling water and returns the mixture to a boil. He pours boiling water into the malt can and swishes it around and pours this into the stainless steel pot to get every drop. The mixture boils for a few minutes, just enough to dissolve the malt.

"This is where the purist parts company," he says, adding two pounds of corn sugar as the malt dissolves. Fermenting in his basement are a five-gallon container of "pure" wheat ale, two five-gallon containers of stout and still another five-gallon jar of English ale. "Pure," he says, means without additional sugar being added. Both corn sugar and granulated sugar "add that traditional cidery taste so characteristic of a lot of home brews," not at all Angerhofer's style.

He stirs in an additional ounce and a half of dried hops, "strictly for the aromatic effect." If he wanted the ale to be more bitter, he points out that he would let the mixture cook another 30 minutes and the hops would completely lose their aromatic effect and add more bitter flavor.

The bubbling mixture, now called a wort (pronounced "wert"), boils a few minutes more just to ensure that everything is dissolved. He stirs occasionally to prevent the malt from carmelizing on the bottom of the pan.

"Germany makes the best beer in the world," he states matter-of-factly while his brew boils on the stove. "Some would disagree and argue that it is England. But there's something about that lager beer. They are legally constrained to use the four basic ingredients and yet produce the most bewildering varieties." Of the over 1,400 breweries in Germany there are 5,000 different beers. "Every little village has two breweries," he says.

One of the perks of his job as an astronomer in the Earth Orientation Parameters branch of the U.S. Naval Observatory is carrying atomic clocks around the world to synchronize everyone into one time scale. When on the road he spends his free time sampling beer. He estimates that he's sampled over 200 varieties; 125 of those have been German lagers. "Still that's only two percent of all the German beers," he says.

He sterilizes a five-gallon fermenting jar by washing it out with a solution that includes a tablespoon of chlorine bleach for each gallon of water. "Bacterial infestation is the biggest problem all home brewers will run into, it is the one thing over which they have the least control," Angerhofer says. You have to think of prevention all along the way in the brewing process. Sterilize all materials--corks, glass containers, bottles, bottle caps, siphon and air lock and wash your hands in the chlorine bleach solution as well. There's no way to gauge bacteria at home, he says, and the only way you can tell is that it tastes sour. Sour beer in the Angerhofer household goes into beer bread made by his wife Lisa, and in meat marinades, and occasionally into "friends with hollow legs."

He rinses the fermenting jar several times to eliminate any taste of chlorine bleach and fills the jar one-third of the way with tap water. He pours in the wort, tops off the bottle with more tap water and covers the top with plastic and a rubber band to carry the 45-pound jar to the fermenting room in the basement. In the morning, once the mixture has cooled to 70 degrees, he will activate and add the yeast by mixing it in a cup of water that has been brought to a boil with a tablespoon of sugar or malt syrup and cooled to room temperature. He then will secure the top with an air lock that will allow excess carbon dioxide to escape without letting air get into the wort.

Yeast, he says, is one ingredient that can vary tremendously and most breweries maintain their own individual strains. "With beer you are striving for uniformity of the product," so it's important to buy a good quality from a supply house. If you buy from a baker you'll get several different strains, he warns. In addition, different yeasts work best at different times of the year. Those that ferment on the top of the wort produce the ales. Bottom fermenting yeasts produce the lighter lager winter beers and aren't suitable to activate at temperatures much over 60 degrees.

Beer should be left to ferment until it has gone completely flat and the surface bubbling has stopped. Otherwise excess carbonation will develop in the bottle from unfermented sugars that can explode during aging. A hydrometer measures how much unfermented materials there are by measuring the brew's specific gravity (or density). Density decreases during the fermenting stage and by taking a reading every few days the home brewer will be able to determine when fermenting stops. At this point the wort has turned from sugar and water to alcohol and water, he says.

The final step will be priming the mixture with sugar to act with the last of the yeast to carbonate the beer while it ages in the bottle. You can add up to a cup of sugar for heavier carbonation, he says. He'll add three-quarters cup of sugar boiled in one cup of water and then siphon the brew into bottles and cap them. The yeast and dried hops remain in the bottom of the fermenting jar. The beer will age for three or four weeks.

Summertime is the toughest time of year to make good home brew, warns Angerhofer. This is a lesson he learned the hard way when his basement temperatures rose above 70 degrees and spoiled eight gallons of his favorite Legendary Number 65. "I opened a bottle and it was wretched. I cried all night," he said.

Taking matters into his own hands, he constructed a tiny 8-by-10 foot windowless fermenting room in the basement. An air conditioner is built into the wall that runs 24-hours a day. The doors are shut tight as a drum. The temperature is kept constant at 70 degrees. His dream, he says, is to turn the room into a one-barrel brewery that will make 31 gallons at a time. His present capacity of five-gallon fermenting jars makes about two cases of 12-ounce beer or 25 champagne bottles. Here is his favorite recipe. DR. BREW'S LEGENDARY NUMBER 65 (Makes 5 gallons) 3.5 pounds Edme Irish Stout Malt 2.2 pounds light, dry malt 1 ounce Goldings hops ( 3/4 ounce pellets) 3 inches licorice root (optional) 1/2 cup Black Patent malt, crushed 1 ounce Hallertauer hops ( 3/4 ounce pellets) 3/4 cup dextrose for priming Bottom-fermenting yeast if fermenting below 60 degrees, otherwise ale yeast

Mix together 2 gallons water, stout malt, dry malt, Goldings hops and optional licorice root. Bring to a boil and boil for 30 minutes. Add Black Patent and boil an additional 10 minutes. Add Hallertauer hops and boil for a final 5 minutes. Total boil 45 minutes. Add water to make 5 gallons, cool and pitch (add) yeast.

Ferment at a somewhat cool temperature (55 to 60 degrees) for best results. Siphon off beer to another container. Mix dextrose with 1 cup water. Bring to a boil. Add to beer. Stir and bottle. This beer can be drunk within 3 to 4 weeks of bottling.

Bottling gravity: Original specific gravity 1.040, final specific gravity: 1.012.

Modifications: Substitute dark dry malt for light dry malt for a heavier-tasting stout. Add up to a maximum 3 pounds total of additional light dry malt. Cascades hops may be used in place of the Hallertauer hops for a slightly more fragrant beer. Add more Black Patent only if you dare! Dr. Brew has successfully used up to 1/2 pound with this recipe, but it took 3 months of aging for it to be drinkable.