The "bread-in-five-minutes-a-day" juggernaut that Jeff Hertzberg and Zoe Francois launched nine years ago continues with the recent release of

The New Healthy Bread in Five Minutes a Day

.

It's an updated version of their 2009 book, which followed their 2007 debut cookbook, Artisan Bread in Five Minutes a Day. We asked Hertzberg whether he ever imagined he'd still be writing about dough nine years after the first book.

"No, of course not," he said, laughing. "My philosophy was that no one should expect a book by unknown authors to do well, but that if we could get the word out, we'd have a chance."

The word got out. Suddenly, people wary of baking bread were succeeding with a dough that could be refrigerated for two weeks and baked at will.

Today, he said, the five titles in the series have sold 715,000 copies. "We thought we'd sell 5,000."

Why such success?

It was a combination of baby boomers who remember what bread tasted like before everyone bought it in the grocery store, and younger people who didn't think that the traditional method of baking worked in their busy lives.

But I also have to say, "Don't overdo it with bread." That's a big carbohydrate source. You've got to be moderate with it. If you're polishing off a loaf every night between two people, that's too much.

That's unexpectedly frank advice coming from an author of a bread cookbook. Must be the doctor talking? (Hertzberg is a physician.)

That is the doctor talking, yes. We wanted to give people control over ingredients, control over portion size. And then we wanted to explore healthier ingredients. But my philosophy is everything in moderation, including moderation. Bread and desserts can be part of a healthy lifestyle.

People are trying ingredients that were little-known a decade ago - Kamut, coconut oil, sprouted wheat. How did you sort out what is honestly healthier and what is merely trendy?

Well, I'm going to be frank again. There's very little scientific proof about exactly which flours are healthier. I use organic a lot, but I don't have absolute proof that it's healthier. But if you're concerned about additives used during its growth, by all means use it.

In a similar way, nobody was talking about coconut oil or flaxseed oil when the first book came out. What I tell people is that any fat source that's melted when at room temperature works just fine. I use olive oil most of the time. It's one that pretty much everyone agrees is a good fat. And avocado oil - I'd make the health claim that it's better than butter.

Now, coconut oil - some claim it's healthier. I don't know. But it lends great flavor to sweeter breads. We don't shun anything. I mean, we have butter in this book.

Can a new bread baker jump into this book even with its more complex flours?

If you start with the master recipe for whole-grain flour and do it exactly as written, you'll learn what a properly mixed dough is supposed to feel like, using standard supermarket whole-wheat flours like Gold Medal and Pillsbury. They have consistent protein levels, so they don't require making different water adjustments. Then once you know how wet the dough is supposed to feel, you can start to work with wheat variants - spelt, emmer, Kamut.

Which new ingredient, or discovered ingredient, most delighted you?

It's kind of a geeky thing to be most delighted by this, but spelt flour worked absolutely as well as regular whole-wheat flour. I thought it would be much denser, but it's not, and has delicious flavor.

But what's closer to white flour than any wheat I've tried is Kamut. We used Bob's Red Mill Kamut flour, and it's better than white whole-wheat. If you're trying to please kids raised on white bread, Kamut is the way to go.

What's next?

We're working on a holiday and celebration breads book in five minutes a day, working with enriched bread and trying to capture as many traditions as we can. We are seeking suggestions on the website about favorite traditional breads. The book will come out in a little under two years.

For recipes and more information go to www. artisanbreadinfive.com.