Sen. Julian Lapides (D-Baltimore) discovered it in a disgruntled letter from a former editor of a Baltimore newspaper. If he put sugar, tapwater, yeast, and peaches in his bathtub and let them ferment, he would be all right. If he substituted malt for the peaches, he would be breaking the law.

The first concoction would create a homemade peach wine; the second would make homemade beer. Maryland and federal laws permit the making of homemade wine for home consumption, but prohibit brewing beer.

"Those German farmers down on the Eastern Shore never heard of that" prohibition, said Sen. Frederick Malkus (D-Eastern Shore), as Lapides presented a bill to legalize brewing beer at home for home consumption.

"If you've had one good bill this session, this is it," Sen. John C. Coolahan told Lapides, a frequent legislative foe.

For his part, Lapides had little to say about his bill, except that he has been given estimates that about 100,000 people - 2.5 per cent of Maryland's population - are merrily brewing beer at home today in violation of the seldom-enforced law.

"The freedom to make beer is a privilege that almost every civilized nation in the world enjoys," testified Oswald Rider, owner of the Jolly Winemaker Shop in Cockeysville.

Rider said he sells "thousands" of books on how to make wine. "I don't think people are buying them simply to fill up Enoch Pratt library" in Baltimore, he said.

Rider said representatives of the Baltimore County liquor board came to his store recently to tell him he was not supposed to sell beer-making implements.

"Everything we sell for making wine can be used for making beer, too," Rider said. "Beer can be easily included as a form of wine just like blackberry wine, honey wine, saki, or what have yoU."

Members of the Senate Economic Affairs Committee had few questions for Rider. Most went something like one asked by the committee chairman, Sen. Harry McGuirk.

"I'd like to ask one question," said McGuirk. "How do you control the alcohol content of beer?"

Just to show how much it appreciated the bill, the committee took the unusual action of voting to approve it today, the same day its public hearing was held.

Meanwhile, the House Appropriations Committee beat back an effort by a Baltimore delegate to eliminate from next year's budget a 890-bed medium-security prison that would be located one half mile from several residential areas in Baltimore.

The committee voted 17 to 4 to keep about $30 million in the budget for acquisition and construction of the prison at the site of an abandoned Continental Can factory in east Baltimore.

The facility was purchased last August by Morton Sarubin, a Baltimore developer who is a cousin of Irvin Kovens, Gov. Marvin Mandel's chief fund raiser. Five months later, Sarubin and Mandel's office entered into a lease that guarantees Sarubin a profit of between $1.1 million and $2.6 million if the legislature approves the project.

"I think Mr. Sarubin is a conniving profiteer," said Del. DeCoursey Bolden (R-Garrett).

Del. Robert Jacques (D-Montgomery), who proposal to limit Sarubin's profit on the purchase to about 15 per cent was also defeated by the committee said, "There is a stench to this bill."

"In 1975, we had Mr. (Jerrold) Hoffberger, who is a friend of Mr. Kovens'. Last year, we had Mr. (William) Siskind who is a friend of Mr. Kovens' . . . this is just outrageous."

In 1975, the state moved to float a $10 million bond issue to facilitate the sale of the Baltimore Orioles baseball team, owned by Hoffberger, to a (Philadelphia group. Last year, the state purchased a large plot of land owned by Siskind for expansion of Coppin State College in Baltimore.

In other action, environmental is its' concern for "obscure little fish and bugs" were blamed for holding up some "tremendous projects" throughout the United States, a lobbyist for the Potomac Electric Power Co. (Pepco) said today in opposing a bill that could block Pepco's plan to build a nuclear power plant on the Potomac River in Charles County.

Attorney james Doyle was responding to claims by environmentalists that the proposed Pepco plant could threaten the foremost spawning area of Maryland's famous rockfish.

The hearing before the House Environmental Matters Committee was on a bill, sponsored by Del. Donald L. Rosenshine (D-Annapolis), that would prohibit the Public Service Commission from issuing permits for power plants in "aquatic sensitive areas," such as where fish spawn.

Representatives of the power plant siting administration of the State Department of Natural Resources testified against the proposal, however, and Rosenshine acknowledged that there are "problems" with his bill. But he said he "wanted to raise the question" this year.

Even proponents admitted that there is "disagreement among the scientific community" about the impact of the proposed plant, according to Nancy Kelly, a biologist for the Chesapeake Bay Foundation.

"Why take the risk" that the plant could impair the spawning of rockfish, shad and white perch, Rosenshine asked, when there are alternative locations?

Also today, the Senate Budget and Taxation Committee approved an amendment to the state budget that would impound $47.8 million of Maryland's contribution to the Washington Metro system if the District of Columbia were to enact a commuter tax.

Sen. Victor L. Crawford (D-Montgomery), who sponsored the amendment, said "it is ridiculous for us to expend millions of dollars of state funds so our citizens can travel more quickly into the District of Columbia to be taxed unfairly."