"You'll have lots of time to chat while you are making your dough," said United Synagogue Women co-chair Dalia Cramer, who jointly organised the event with rebbetzin Joanne Dove.
But even Chief Rabbi Ephraim Mirvis struggled to command silence as he told the assembled bakers: "Tonight we are putting the yeast into Yiddishkeit. And what we and so many thousands of others are doing will enable our connnection to Yiddishkeit to rise and rise."
Estimates suggested that "there will be more than 100,000 people in this country who will be engaged with Shabbat".
United Synagogue president Stephen Pack said: "The volume of noise is amazing. It's uplifting that there is such a huge cross-section of the community here." And while Mr Pack kneaded his dough manfully, his plait-work suggested that he will not be offered a job in a bakery any time soon.
The event attracted a diverse crowd - from Charedi boobas with daughters and granddaughters to women in sleeveless tops and jeans.
Eight-year-old Hasmonean Primary pupil Atara Fachler plaited her challah with surgical precision. "It's hard making the dough," she said. "You have to do a lot of kneading, but it's quite easy to plait."
Added her sister, Eliane, 10: "It's great for all Jews to get together and have fun. It's lovely to see everyone from all parts of the religion together."
From Edgware via Israel, Sharron Samuels, who attended with her 15-year old daughter, Natalie, welcomed the "opportunity to bring people closer to the religion. It's very important for the next generation to be practising Jews."
Also from Edgware, Emma Morris, 32, said: "It's amazing. It's not denominational. It doesn't matter whether you are Reform or Lubavitch. I have a lot of respect for Rabbi Mirvis. He is so warm and he is a people person who doesn't put himself on a pedestal."
Senior citizen Norma Frankel was making challah for the first time. "It's different from what I'd normally do on a Thursday night," she explained. "I play bridge." But she was doubtful if she'd drop the cards for bread-making a second time.
Zehava Taub, wife of Israeli Ambassador Daniel Taub, was one of a number of guest speakers.
TV producer Dan Patterson, who sang Hebrew songs from the podium with half of his band, Jonah and the Wailers, observed: "There is so much energy here that if you could tap into it, who would need wind-farms?"
Participants donated a sixth of their dough for loaves earmarked for charity, which were baked in the club's kosher kitchen later that night.
They left carrying their still expanding challahs to their cars to the backdrop of exploding Diwali fireworks.
But not everyone was convinced of the fruits of their labours. "I think I'm still going to go to Grodzinski's in the morning," said one woman.
