Almost every 'tea factory tour' near town is a 10-minute walkthrough followed by a hard sales pitch in the attached shop, with tea and chocolate priced well above what you'd pay at a regular Charing Cross store. If you want the real process, visit an actual tea estate near Coonoor instead.
Commercial tea cultivation in the Nilgiris dates to the 1830s, when the British began experimenting with Chinese and Assam tea varietals on the hill slopes around Ooty and Coonoor after coffee crops failed to thrive at altitude. The working factory and attached museum on Doddabetta Road demonstrate the CTC (crush-tear-curl) processing method that came to dominate the Nilgiri tea industry in the 20th century, and today Nilgiri tea holds Geographical Indication (GI) certification. Most Ooty tea factory tours depart from or near Charing Cross, the town's central junction.