Mitzvah Day brought generations together, with many young participants engaged in activities assisting elderly community members and Holocaust survivors.
Teenagers at the London Jewish Cultural Centre baked scones and miniature Victoria sponges and prepared finger sandwiches with chef Lisa Roukin for a tea party for survivors.
LJCC youth co-ordinator Laurence Field said: "We do so much work with survivors and activities with young people but the two rarely interact. Holocaust survivors give up their time to speak to young people in schools and this is an opportunity to give back to them."
Buchenwald survivor Bob Obuchowski was at the tea with wife Marie. "The food is fantastic," he said. "It's lovely to be here and spend time with young people. I speak in a lot of schools about my experience in the Holocaust."
This year saw the launch of Mitzvah Day Active - a means to involve young adults and professionals without a close affiliation to a synagogue or charity.
Ten participants in the Adam Science leadership programme organised an Active project, through which more than 300 individually-decorated cupcakes were delivered to charity shop volunteers, police, firemen and hospitals.
Synagogues were encouraged to stage activities relevant to their their youngest members. A flagship environmental project organised with the Big Green Jewish campaign gave communities the chance to grow their own mint.
Children at Hampstead Garden Suburb Synagogue cheder decorated 50 boxes and packaged the mint to send to adult Norwood residents. "They can make tea with it, but it will take a long time to grow," said six-year-old Joel Brick.
Mitzvah Day co-ordinator Sarah Callman added: "We could have planted the mint ourselves but we wanted to do something charitable with it."
Cheder pupils also produced calendars for Jewish Care residents, wrapped toys for sick children helped by Camp Simcha and packed lunches for a homeless shelter in Muswell Hill. "I'm always surprised by how generous people are," Ms Callman said. "I always panic buy extra things and then we end up with so many gifts and donations.
"We made sure the day was not chaotic and that the pupils understood how important what they were doing is."