The £22.5m investment would create 18 new jobs and increase production capacity at the site by 30%, Britvic said.
The new line would enable “faster and more efficient production” of brands including Tango and Pepsi Max, it added.
Britvic holds the licence to make, distribute and market PepsiCo products in the UK.
“Opening the sixth bottling line at Beckton marks the latest milestone in a series of investments into our supply chain,” said Nigel Paine, supply chain director at Britvic.
“As we continue to grow and meet increasing demand, boosting our capacity at the Beckton site allows us to keep delivering on our goals and create a resilient business.”
Britvic had earlier this year invested £8m to improve the energy efficiency of its Beckton factory, which now employs more than 240 people.
The Hemel Hempstead-headquartered company operates factories in Rugby, Leeds and Beckton, and also has a national distribution centre in Lutterworth, Leicestershire.
In recent years, the company said it had invested £40m in improvements at its Rugby site – including adding a fifth canning line – and £19m in upgrading its national distribution centre.
Its products are to continue to be produced in Europe, however, due to Britvic’s lack of dairy production capabilities.