The silvery Christmas tree glinting behind her in her partner’s sitting room is reusable and the tree from last year has been planted in the garden. She wrapped her presents with used paper and the Christmas lunch has been turned into a week’s meals: turkey for vol-au-vents for her brother’s birthday, the bones into stock, Brussels sprouts and roast potatoes stirred into bubble-and-squeak.

Liz Goodwin is Britain’s recycler-in-chief, the woman who, as head of WRAP (the Waste & Resources Action Programme), spends £80 million of taxpayers’ money a year on getting us to waste less.

But forget any image you may have of an activist at the barricades: her politics are based on the fundamentals of good housekeeping that she inherited from her mother. She is mild, old-fashioned and somehow very English.

Can the decent, gentle approach work on lazy consumers and greedy producers? It is her objective to find out and, with our landfill sites groaning, she does not have long.

“If we start beating people up and saying you must do that, you must do this, you lose all that goodwill, and then you’re having to badger them all the time. I would just prefer to keep it on positive footing,” she says.

It is a theme we return to again and again. Where many firebrands talk of using recycling laws to save the planet, she leads us gently back to the kitchen, the Mrs Beeton of environmentalism.

While most of our homes are now glutted by an excess of paper, bottles and - most of all – food, the house near Oxford is spic and span.

Where politicians promise to cut the amount of trash going to landfill sites, Ms Goodwin has to make it happen. How? The next big thing in British recycling, she promised us, is the most traditional – food.

“I’ve identified food waste as our number one priority,” she says.

“Of everything that we could do, if we could reduce food waste, that would make the biggest difference in terms of carbon. Every tonne of it saved means you avoid 4.5 tonnes of carbon. That’s enormous and it’s not well known.”

One in three bags of shopping ends up in landfill, she says, £8 billion worth of it each year, up to £400 a household. “If you think about all the energy that’s gone into producing that food, all the farming, the storage, the distribution, the preparation and then, if it’s wasted, it then goes into landfill and produces methane . . . I think that weekly food waste collection has a big part to play.”

With pilot schemes already going well, within two to three years she is determined to see pails of rotting food routinely collected along with the rubbish, then processed at local plants to generate electricity. She foresees a day when every town will have its own anaerobic digester.

In the meantime, some tips. Have a favourite mug to measure out your rice, she advises. Check the fridge before you go shopping, and don’t be boggled by “best before” dates.

“My mother would use the good old sniff test and a bit of a taste, if it tasted all right, it’ll find a use,” she says.

Rather than exotic recipes from Nigella, children should be taught the forgotten art of using up leftovers (needless to say, the over-65s are the most thrifty with food).

It should be part of the curriculum? “Yes. We need to be able to know what to do with food, and not just get scared when we look in the fridge and think what do I do with those things?”

Her favourite tip for us profligate consumers? If you buy too big a portion, put half in the freezer. “It’s not rocket science,” she says. “Instead of just putting it back in the fridge and two days later thinking, ‘Oh, I should have used that’, and having to throw it away.”

She continues: “If we’re cooking a meal for ourselves, we [she and her partner, Bruce, an accountant and a father of three] often consciously make enough for a third plate, because it can go in the freezer and then if one of us is back late or something it’s a quick meal – and it avoids the wastage in the first place.”

That’s it? Never mind the younger generation’s burning passion to make a difference by direct action.

The most effective direct action, according to Ms Goodwin, boils down to doing stuff our mothers and grandmothers did by rote. Forget Hollywood celebrities and international politicians, our interest should lie in mucky, unglamorous scraps.

Typically, she is not pushing to force shops to use less packaging. She wants to wait and see if they can manage it on their own. She talks enthusiastically about how supermarkets should offer a service to refill empty washing up bottles and so on, like they do in Australia and America.

But compel them to get going on these plans? No. People, especially here in Britain, don’t like to to be told what to do, she says.

Couldn’t you do a bit more to beat the drum? “I’m sure there’s more we can do.” What if her approach means that our already lamentable progress compared to the rest of Europe continues to be slow? Well, “let’s see”.

What about the online retailers, such as Amazon, who have refused to sign up even to the voluntary agreement to reduce packaging? “I think it’s something we ought to look at.”

Does she leave her packaging at the till, like some environmental activists?

“I think that’s fine for people who want to do it, but I don’t.”

Why? “Because I’m not a campaigning person like that. I want to make a difference, but I want to do it in my own way. I don’t need to be seen to be making headlines. I can be far more effective in actually working with the retailers.”

After gaining a PhD in chemistry Ms Goodwin worked for ICI and was alarmed at the “massive effect” the company was having on the environment. She decided that she wanted to devote her life to something more worthwhile.

When, we wondered, did she last buy something wasteful? She thought long and hard. “I’m going to struggle with this one. I’m not entirely sure. It would probably be something silly like some new towels when, actually, the others are not too bad.”

If all of us were as modest and conscientious as Ms Goodwin, we’d have this recycling thing all wrapped up in a (recyclable) Jiffy. If only.

Liz Goodwin

Age 46

Home life Lives near Oxford

Education
Chichester High School for Girls; University College London; PhD in chemical physics at Exeter University

Research career
Worked for ICI researching alternatives to CFCs that harm the ozone layer, and later held a number of technical and production jobs

Environmental career
Worked as an environmental consultant for Zeneca. Joined Wrap in 2001 as director of the materials programmes, promoting the use of recyclables. Appointed chief executive in 2007


Watch your waste

80%
The estimated increase in the amount of food wasted in Britain over the Christmas season, compared with the rest of the year

£275m
Worth of food, or about 230,000 tonnes, will be thrown away over the holiday. Most of this food reaches landfill sites where it emits methane, a powerful greenhouse gas.

20%
Of Britain’s greenhouse gas emissions are associated with food production, distribution, disposal and storage
Source: WRAP

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