Kenyan President Mwai Kibaki has ordered a nationwide investigation into the brewing of illegally-made alcohol.
Some of the victims have gone blind
The number of people killed by poisoning in Machakos, south-east of Nairobi, rose to at least 48.
More than 50 others went to hospital after drinking the illegally produced beverage, which was mixed with methanol to make it stronger.
It was drunk over the past few days in Makutano, south of the capital Nairobi.
Some of those in hospital have lost their sight, while others who are critically ill have been transferred to Nairobi's Kenyatta National Hospital.
President Kibaki condemned "greedy brewers" and said a probe was needed to ensure the tragedy was not repeated.
Kenyan police say they have made several arrests but are still searching for a woman said to have distributed the brew.
One of the victims, Mwoka Musimi, 30, said after one drink he "nearly died".
"I just lost my consciousness. My wife took me to hospital... I'm lucky that I didn't lose my sight or die like my friends."
Some people were found dead in their homes.
Methanol, a poisonous chemical used as a solvent or antifreeze, has been blamed for hundreds of deaths in Kenya in recent years.
In 2000, at least 134 people died and hundreds of others were admitted to hospital after drinking poisonous alcohol in Nairobi.
The unlicensed manufacture, distribution and sale of alcohol is illegal in Kenya, but the trade in cheap brews is widespread because they offer a much cheaper way of getting drunk than highly taxed legal beers and spirits.