TORONTO -- An exuberant Julia Roberts calls working on her latest film, "August: Osage County," "the best acting experience of my life."


The actress was bubbling with enthusiasm the day after the highly anticipated adaptation of Tracy Letts' Pulitzer Prize-winning film premiered at the Toronto International Film Festival. In the film, Roberts plays the eldest daughter of a brutally honest matriarch, played by Meryl Streep.


"I've never worked so hard in my life – and I've given birth to three children," Roberts told reporters Tuesday.


The large cast lived near the on-location set in Oklahoma, devoting themselves to capturing Letts' dialogue. The film, to be released Dec. 25, drew mixed reviews at the festival but praise for its performances.




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  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Harvey Weinstein


    Harvey Weinstein arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. The movie mogul talks to Associated Press in an exclusive interview about the "12-12-12" (Sandy benefit at MSG) documentary he premiered at TIFF, and how they amassed the biggest names in music. He also spoke about his TIFF premiere of "August: Osage County," and how proud he is of "The Butler." (Photo by Evan Agostini/Invision/AP)




  • Harvey Weinstein


    Harvey Weinstein arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. The movie mogul talks to Associated Press in an exclusive interview about the "12-12-12" (Sandy benefit at MSG) documentary he premiered at TIFF, and how they amassed the biggest names in music. He also spoke about his TIFF premiere of "August: Osage County," and how proud he is of "The Butler." (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Juliette Lewis


    Juliette Lewis arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Juliette Lewis


    Juliette Lewis arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts, Dermot Mulroney


    Julia Roberts, left, and Dermot Mulroney arrive at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Chris Cooper


    Chris Cooper arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts, Dermot Mulroney


    Julia Roberts, left, and Dermot Mulroney arrive at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts, Dermot Mulroney


    Julia Roberts, left, and Dermot Mulroney arrive at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Dermot Mulroney


    Dermot Mulroney arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Abigail Breslin


    Abigail Breslin arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Dermot Mulroney


    Dermot Mulroney signs autographs for fans at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Dermot Mulroney


    Dermot Mulroney arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Abigail Breslin


    Abigail Breslin arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Juliette Lewis


    Juliette Lewis arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julianne Nicholson


    Julianne Nicholson arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Julia Roberts arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Ewan McGregor


    Ewan McGregor arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Ewan McGregor


    Ewan McGregor arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Dermot Mulroney


    Dermot Mulroney arrives at the premiere of "August: Osage County" on day 5 of the Toronto International Film Festival at the Roy Thomson Hall on Monday, Sept. 9, 2013, in Toronto. (Photo by Evan Agostini/Invision/AP)




  • Julia Roberts


    Actress Julia Roberts poses for a photograph on the red carpet at the gala for the film "August, Osage County " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Chris Cooper


    Actor Chris Cooper poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Chris Cooper


    Actor Chris Cooper poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Juliette Lewis


    Actress Juliette Lewis poses for a photograph on the red carpet at the gala for the new movie " August, Osage County " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • John Wells


    Director John Wells poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Juliette Lewis


    Actress Juliette Lewis poses for a photograph on the red carpet at the gala for the new movie " August, Osage County " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Abigail Breslin


    Actress Abigail Breslin poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Abigail Breslin


    Actress Abigail Breslin poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Abigail Breslin


    Actress Abigail Breslin poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Abigail Breslin


    Actress Abigail Breslin poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Abigail Breslin


    Actress Abigail Breslin poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Dermot Mulroney


    Actor Dermot Mulroney poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Dermot Mulroney


    Actor Dermot Mulroney waves as he signs autographs for fans on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Abigail Breslin


    Actress Abigail Breslin poses for a photograph on the red carpet at the gala for the film "August, Osage County" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Julia Roberts


    Actress Julia Roberts poses for a photograph on the red carpet at the gala for the film "August, Osage County " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Julia Roberts


    Actress Julia Roberts poses for a photograph on the red carpet at the gala for the film "August, Osage County " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Julia Roberts


    Actress Julia Roberts poses for a photograph on the red carpet at the gala for the film "August, Osage County " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Scarlett Johansson


    Actress Scarlett Johansson wears a ring as she poses for a photograph on the red carpet at the gala for the new movie " Under The Skin " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Scarlett Johansson


    Actress Scarlett Johansson poses for a photograph on the red carpet at the gala for the new movie "Under The Skin" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Jonathan Glazer, Scarlett Johansson


    Actress Scarlett Johansson poses for a photograph on the red carpet at the gala for the new movie "Under The Skin" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Scarlett Johansson


    Actress Scarlett Johansson poses for a photograph on the red carpet at the gala for the new movie " Under The Skin " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Scarlett Johansson


    Actress Scarlett Johansson poses for a photograph on the red carpet at the gala for the new movie " Under The Skin " during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Jonathan Glazer, Scarlett Johansson


    Actress Scarlett Johansson, right, and director Jonathan Glazer pose for a photograph on the red carpet at the gala for the new movie "Under The Skin" during the 2013 Toronto International Film Festival in Toronto on Monday, Sept. 9, 2013. (AP Photo/The Canadian Press, Nathan Denette)




  • Paul Haggis; Liam Neeson; Mila Kunis; Adrien Brody; Olivia Wilde; Moran Atias; Maria Bello, Loan Chabanol


    Actors Adrien Brody, left, and Liam Neeson, centre, pose for a photograph with director Paul Haggis, right, on the red carpet at the gala for the new movie "Third Person" during the 2013 Toronto International Film Festival in Toronto on Monday, September 9, 2013. (AP Photo/The Canadain Press, Michelle Siu)




  • Paul Haggis; Liam Neeson


    Writer and director Paul Haggis, right, and actor Liam Neeson, left, pose for a photograph on the red carpet at the gala for the new movie "Third Person" during the 2013 Toronto International Film Festival in Toronto on Monday, September 9, 2013. (AP Photo/The Canadian Press, Michelle Siu)




  • Liam Neeson Adrien Brody


    Actors Adrien Brody, left, and Liam Neeson, right, pose for a photograph on the red carpet at the gala for the new movie "Third Person" during the 2013 Toronto International Film Festival in Toronto on Monday, September 9, 2013. (AP Photo/The Canadian Press, Michelle Siu)