Cake Bakers and Trouble Makers, BBC Two

Lucy Worsley, historian and TV presenter – or perhaps that should be the other way round, since the BBC seems to give her a new series about every six weeks  – is the unrivalled queen of the soundbite. Subtitled as Worsley's "100 Years of the WI", this canter around the stately circumference of the Women's Institute, now 100 years old, was niftily pinned together with sonorous adjectives and cacophonous alliteration.

Striding through some strangely pea-green English countryside, Worsley defined the classic image of the WI lady for us: "She's that bossy woman belting out 'Jerusalem'. Or a rosy-cheeked do-gooder making lovely cakes and jam." The WI is "a formidable force that has helped to forge modern Britain," and its members are "doughty defenders of our green and pleasant land". WI meetings were "three parts domestic accomplishments and one part sherry and shenanigans".

Finding the balance between the celebrity-presenter and telling the story is never easy

In between all these syntactical starbursts, this was a solid history of the WI which sometimes ground to a halt in a quicksand of places, names and dates. The early part about feisty arsonist and suffragette Edith Rigby and Canadian WI pioneer Madge Watt (the latter kick-started the British WI in Anglesey in 1915) seemed especially entangled in narrative knotweed.

However, whenever the exhaust started popping and belching smoke, Worsley was ready with the documentary equivalent of a comedy sketch. For instance, she gave us the diverting story of "Cuthbert Rabbit" to illustrate the way the WI started a toy-making business during World War One because hostilities had terminated supplies of previously popular German toys. The WI was fabled for its cake-making, and Worsley rather smugly demonstrated her own expertise in this field. As if that wasn't enough, she was terribly pleased with her mastery of an American-made jam-canning machine. Of course, there was quite a long segment about the nude WI calendar women of Rylstone.

Finding the balance between showcasing the celebrity-presenter and telling the story at hand is never easy, and while Worsley radiates a cheeky, knowing perkiness, it does have a tendency to reduce everything around her to props and wallpaper. Thus, while she was full of praise for the WI's history of robust campaigning for women's rights – they were battling stoutly for equal pay for women as early as 1943, and weren't happy at the way wartime women were lumbered with a colossal unpaid workload of washing, cooking and childcare when evacuee families were billeted on them – there was still a gently pervasive sense that she thought this whole WI thing was rather quaint and old-fashioned. A wartime WI report about scabby, lice-infested evacuee children and their "bad" mothers almost caused Worsley an attack of the politically-correct vapours (she thought the author sounded like "a crazy right-wing person" talking about immigrants).

Nonetheless, the film probably told most of us a lot of stuff we never knew about the WI, and shone useful light on the organisation's genuinely radical roots. And what more can you ask from what we must, if we're honest, file under "docutainment"?