MANOUSH ZOMORODI: This is Science Friday. I’m Manoush Zomorodi, sitting in for Ira Flatow.

There’s that old expression “waste not, want not,” but sadly, most of us– in the developed world, at least– seem to have forgotten it. In the US, we throw out a third of our food– a full third– every year. Tens of billions of pounds of perfectly good food are wasted.

And I know we’ve all been there. That misshapen tomato with a bruise– it’s way too ugly to slice up for your salad, right? Or that hunk of cheese with that little green mold spot? You could have cut it off, but you just threw it in the garbage instead.

Or maybe you just didn’t know what to do with those dirty carrot tops or cabbage cores and broccoli stems, so they ended up in the trash. Is there anything you could do with them?

Well, my next guests– a Danish chef and a fine-dining forager– are here to keep that stuff out of the garbage and get it onto your kitchen table. They will literally make you want to scrap your dinner plans with their new book “Scraps, Wilt & Weeds: Turning Wasted Food into Plenty.” You can check out an excerpt at sciencefriday.com/scraps.

And I want to introduce to you Mads Refslund. He is a chef based here in New York City. He’s the founder of Noma, that famous restaurant in Copenhagen, and he’s co-author of “Scraps, Wilt & Weeds.” Lovely to see you.

MADS REFSLUND: Thank you for having me.

MANOUSH ZOMORODI: And Tama Matsuoka Wong is a professional forager for restaurants here in the New York City area, and she’s Mads’s coauthor.

TAMA MATSUOKA WONG: Nice to see you.

MANOUSH ZOMORODI: Nice to see you. You brought me some goodies, which I’m going to eat in a minute. I want to welcome you both.

And I want to ask you listeners– we want to know what’s in your fridge. Call in. Give us your tired, your wilted, your stale ingredients, and Mads and Tama are going to tell you what to do with them.

Our number is 844-724-8255. That’s 844-SCI-TALK, or you can tweet us @scifri.

So Mads, I want to start. You live here in New York City now. And this is a place where, of course, there are trash bags piled up on every corner.

Sometimes it smells like rotten food. Not today– it’s too cold today. But instead of this being a turnoff for you, you kind of write that you find a lot of inspiration from trash.

MADS REFSLUND: Yeah. You know, if you go down the West Village, or if you go to the East Village or something, and you see all the trash on the street, you’re not getting inspired by that, of course. You get a little bit sad about it.

But yeah, when I see like a Christmas tree lying on the ground after Christmas evening, or you see the pumpkins after Halloween– yeah, get inspired. You can use that for something.

MANOUSH ZOMORODI: Just to give us a little taste of what you could use it for. I mean, in the book, I have to say, I was really astounded by pumpkin jerky. That was not something I would have thought to make.

MADS REFSLUND: But there’s so many pumpkins they’re throwing out after Halloween, so we did so many things with the pumpkin. We dried it, and we made flowers with it. We could use it for pasta. We can use it for teas. We can use it for soups, whatever– and jerky, also, of course.

MANOUSH ZOMORODI: Of course, jerky.

MADS REFSLUND: Of course. You just dry it for days. It took a long time to dry it.

MANOUSH ZOMORODI: Did it?

MADS REFSLUND: Yeah, a very long time.

MANOUSH ZOMORODI: That is tasty. Tama, you forage professionally for restaurants here in New York City. What is foraging, actually? What’s your day like?

TAMA MATSUOKA WONG: My day? Well, it’s different most of the time, but foraging is really finding things in nature. So I think that you’re finding things that are in nature, and you’re picking them and finding deliciousness in them.

MANOUSH ZOMORODI: I mean, if you’re doing it for restaurants, you must have to find a lot of deliciousness.

TAMA MATSUOKA WONG: Yes, there’s a lot of logistics involved in that, and doing it as a business is different. It’s much easier just to do it for yourself in your backyard. But obviously, if you’re going to do it as an innovative business, there’s a lot of logistics and discovery, but always challenging.

MANOUSH ZOMORODI: And secret spots, I bet, too. Now you brought me something, and you told me I should really only eat– what am I holding here?

TAMA MATSUOKA WONG: So right now you’re hold– so people may think there’s nothing out there now because actually it’s snowing here. But there are some things that are wild that grow in this snow, and that is garlic penny-cress.

MANOUSH ZOMORODI: Can I eat it?

TAMA MATSUOKA WONG: Yes.

MANOUSH ZOMORODI: OK.

[CRUNCH]

Oh, it’s a little spicy. Oh, this is good!

TAMA MATSUOKA WONG: It’s good, right?

MANOUSH ZOMORODI: I want to a little cheese with that.

TAMA MATSUOKA WONG: It’s really interesting. We think that this is something pretty new, in that, if you look at some of the old books that are out there, they don’t have this particular species.

So this is a species that hybridized between two different mustards in the wild. And that’s why it has a kind of sweetness and complexity. It’s not just plain bitter.

MANOUSH ZOMORODI: Yeah, it’s yummy. So Mads, what sort of things were you looking around in your kitchen, as a chef, and thinking, golly, I wish I could find a way to use something? I know that brussels sprouts was something that you thought– I love Brussels sprouts.

MADS REFSLUND: I think using everything, you know, but there’s some things you cannot eat, of course. But brussels sprouts– it’s them for that. It took us a long time to break that code. But actually, if you grill them, and you cut into the center, you have the heart of the brussels sprouts.

MANOUSH ZOMORODI: You’re talking about like when we go to the farmers market.

MADS REFSLUND: The stalk. The big stalk where all the brussels sprouts are growing from.

MANOUSH ZOMORODI: There are New Yorkers and maybe other people across the country who have only ever seen brussels sprouts in a mesh bag, and that’s how they’ve bought them.

MADS REFSLUND: Exactly, but I like to see it as a wholeness. You see the whole plant, the whole–

TAMA MATSUOKA WONG: I think that’s one of the main points that Mads is– what we’re working together, is that he always wants to go back to see how it actually lives as a whole in nature. Because if you can see the thing as a whole, then you can start to see what all the infinite possibilities are from it. But if you only see it in a little package of parts, you’ll only think of it one way.

MANOUSH ZOMORODI: Right, that is so true. OK, let’s take a call. I think we have John calling from Menlo Park in California. Hey, John.

JOHN: Hi.

MANOUSH ZOMORODI: What’s going on? What’ve you got there?

JOHN: Not much, just hanging out. I have old potatoes that are kind of sprouting a little bit, if you know what I mean.

MANOUSH ZOMORODI: Yup, I do. They have little flowers coming out of them.

JOHN: Yeah. And then some tortilla chips that are almost stale, not quite.

MANOUSH ZOMORODI: OK, this is good. This is good. OK, John, I’m going to put it to them. Thanks for calling.

TAMA MATSUOKA WONG: So I can start off– that if it is green– There’s something we did research that we talked about. And we do actually have sort of scientific experts that we work with at NRDC who look at the scientific side.

And if you have green on your potatoes, you actually– if they have turned green, you should not be eating the green part. They do have toxins.

MANOUSH ZOMORODI: OK, John, did you hear that?

TAMA MATSUOKA WONG: But if they’re not yet green, they should still be OK if you cut away the sprouty bits.

MANOUSH ZOMORODI: So just cut off the top. That part– stick it in the compost. But use the– what if they’re a little bit smushy, the potatoes?

MADS REFSLUND: Smushy or wrinkled?

MANOUSH ZOMORODI: I don’t know. You tell me.

MADS REFSLUND: If it’s smushy, like rotten, you should not eat it. But if it’s like a wrinkle and old, in a way, you can still eat them.

You can do amazing things with the potato peelings, actually. We did a [? sous ?] [? pato. ?] We did infusions and oils, all these.

MANOUSH ZOMORODI: Isn’t it really bitter– potato peelings?

MADS REFSLUND: Just wash them. No, no, it’s not bitter bitter, no. It tastes like– if you roast all the peelings in the oven, it tastes like a baked potato.

MANOUSH ZOMORODI: Oh. Really?

MADS REFSLUND: We have a soup in the book. It’s like with baked potatoes. It’s the taste of baked potatoes. It’s a soup of baked potatoes. So it’s just a peeling from potatoes.

MANOUSH ZOMORODI: And then tortilla chips– I think he should just crumble them up and toast them. What do you think?

TAMA MATSUOKA WONG: Yeah, like, how do you–

MANOUSH ZOMORODI: Right? I’m getting in the mood here.

MADS REFSLUND: I’m not so much into processed foods.

MANOUSH ZOMORODI: Oh. Sorry, John.

TAMA MATSUOKA WONG: But the potato skin also has some of the nutrition, actually. Most of the nutrition is in the skin, so peeling off the peel of the potatoes seems really like a waste in more than one way.

MANOUSH ZOMORODI: OK, so Crystal is calling from Hot Springs, Arkansas. Crystal, what’ve you got in your kitchen?

CRYSTAL: Well, my husband and I have recently started juicing, and there’s a lot of pulp left. And I’m not sure what to do with all of it. It feels wasteful just to only compost it. So I was wondering what else I can do with all of the pulp left?

MANOUSH ZOMORODI: Mm, such a good question. Thanks, Crystal. Mads, are you a juicer?

MADS REFSLUND: Yeah, I have a juicer. It’s actually– you’re using juice pulp for a lot of different things. To start with, if you want to use it fresh, you can put it in some falafel. You could do it like [INAUDIBLE] do– using it for a vegan burger.

TAMA MATSUOKA WONG: Veggie burgers.

MADS REFSLUND: Yeah, veggie burgers. And I think he sold it at Shake Shack.

TAMA MATSUOKA WONG: I don’t know. Shake Shack was even selling veggie burgers from– I think–

MANOUSH ZOMORODI: From juicing pulp?

TAMA MATSUOKA WONG: Yes.

MADS REFSLUND: Yeah. So the next day, you would drying it and pulverized it into flour. And we used it for pastas.

Or actually, you just dry it, put it in some water, into a cup and put hot water on it. You have mixable bullion.

MANOUSH ZOMORODI: And I actually read in the book, Mads, that your girlfriend would take some of the pulp and turn it into like a scrub for the shower.

MADS REFSLUND: Yeah, that’s true. She did that.

MANOUSH ZOMORODI: So you’re eating it, you’re scrubbing it. There’s so many uses. I love that.

TAMA MATSUOKA WONG: And again, not to kind of put on the health thing, but a lot of the fiber that is good for you in the vegetables actually is in the pulp, and you should not be throwing it away, if you can.

MANOUSH ZOMORODI: All right I want to go to Suellen, who’s calling from Cincinnati, Ohio. Hi, Suellen.

SUELLEN: Hi.

MANOUSH ZOMORODI: Tell us your ingredients.

SUELLEN: OK, withered apples.

MANOUSH ZOMORODI: Anything else?

SUELLEN: And some yellowish parsley.

MANOUSH ZOMORODI: Now, that’s a good one.

SUELLEN: And I have some chickweed. It’s not too withered up yet, but I don’t know too many things to do with it. So I thought they might have some more ideas.

MANOUSH ZOMORODI: Cool.

SUELLEN: I do forage.

MANOUSH ZOMORODI: Oh, you forage, as well? OK. Very cool. Thanks, Suellen.

All right, so withered apples, chickweed, and yellowed parsley. I have been a victim of the yellow parsley and I usually just throw it.

MADS REFSLUND: In a way, when you buy herbs, and it’s in the recipe, you only need like half of the amount of herbs you have. Instead of putting it back into the fridge, just hang it up and dry it.

It’s the same thing when you go to the supermarket and buy the dry herbs. You actually just have it hanging in your kitchen. So don’t put them back into the fridge because you forget about them.

MANOUSH ZOMORODI: Yeah, and then they’re moldy, and then you’re sad.

MADS REFSLUND: And yellow– it’s not because it’s bad. You can still boil it. You can still use it or dry it. It’s just a stage of getting into the next level.

With the apples, we have worked a lot with these apples, like the fruit, and it’s like ugly fruits, in a way, we call that. And we had dried into raisins. You have a dessert with it, because it’s almost like a natural thing.

The apple falls down to the ground and lying in the soil and the grass. It’s starting to break down. It starts to ferment. And it’s getting sweet. And they thought it as rottens.

So we did, actually, a dessert where we are calling for fruits, and we had to take wrinkled apples and cut into small pieces, cooked it in simple syrup, and was drying it for a day. And after that, it was looking like raisins.

MANOUSH ZOMORODI: Dessert!

TAMA MATSUOKA WONG: There are tons of things you can do with withered apples, as long as they’re not rotten. You can bake with them. There are lots of things. I would also say something about the chickweed.

MANOUSH ZOMORODI: Yeah, tell us.

TAMA MATSUOKA WONG: So the chickweed–

MANOUSH ZOMORODI: What is chickweed?

TAMA MATSUOKA WONG: Chickweed is a small, herbaceous plant– weed– that grows all over people’s gardens. And actually being of Asian ethnicity, it is actually one of the seven precious herbs of spring for Japanese. They don’t call it chickweed, so, therefore, probably is fairly much a gourmet item there.

And it’s very mild, so if you’re just chopping it up, you could have it as an Asian dish, or you can substitute it for spinach. One way we like to do– a Western way– would be to chop it up and use it for a topping for a bruschetta or toast or something. And another, sort of a classic way, with sesame and soy sauce and a little bit of sugar that you could have as a side dish.

MANOUSH ZOMORODI: This is Science Friday from PRI– Public Radio International.

Mads, one thing that makes me sad every– I love– I’m crazy for coffee, and especially really good coffee. It seems I want to just– I don’t know. I want to be– rummage around in my coffee beans. But is there anything I could do with them– the ground– after I make myself–

MADS REFSLUND: Yeah, definitely. We have used it so many times, because it’s a shame to throw all those coffee grounds away after. So you can reuse it.

In Africa or other places in the world, they don’t throw it out after. They’re rebrewing it again and again and again and again, because there’s so much flavor left, all the flavor in it. So I’ve done it like a panna cotta with it.

So actually, instead of throwing it out after you’re done– your cappuccino, espresso thing– you just put it into milk or cream, and bottle it up one more time, and you have all the flavors of the leftover coffee taste.

MANOUSH ZOMORODI: Could that be a latte for later in the morning? Or is it not going to have enough flavor?

MADS REFSLUND: It could be.

MANOUSH ZOMORODI: I’m going to try it.

MADS REFSLUND: You should try it. Or you could use it into a body scrub again.

MANOUSH ZOMORODI: Right? Or a body scrub. Everything just make in a body scrub.

MADS REFSLUND: It’s actually really good, that one.

MANOUSH ZOMORODI: It sounds so good. Yum. OK, so Tama, one thing that I feel particularly guilty about is I cut up– my family eats ridiculous amounts of carrot sticks, which is great.

But after reading your book, I’m wondering if we’re going about this all wrong, in that I cut the tops off, and I cut the bottom off, and I scrape off the skin, because my kids– the minute anything looks a little brown, they’re not going to eat it. But is that total waste?

TAMA MATSUOKA WONG: I don’t see why you should have to peel off the peel of the carrot, I guess, if you’re asking. And. then, of course, the tops can be used as a green.

And, I think, for myself, in just sort of easy and not having too much time, a lot of the pestos that are there including the carrot tops, the celery scraps, are some of my favorite recipes. So they’re so easy.

And the main difference for myself and people who are testing it was that they had this image in their mind that, oh, this is going to taste like straw and be all bad. But it actually tastes delicious. I just tell people, try it, and you’ll be really surprised.

MANOUSH ZOMORODI: Carrot tops?

MADS REFSLUND: Carrot tops is good, yeah.

MANOUSH ZOMORODI: Just eat them?

TAMA MATSUOKA WONG: Well, you chop them up.

[INTERPOSING VOICES]

MADS REFSLUND: I would bring it down with something because they’re a little bit bitter.

MANOUSH ZOMORODI: OK.

TAMA MATSUOKA WONG: So there’s a recipe about how to kind of balance, and it turns out really well. But you’re not just taking a hunk of carrot tops and eating it like Bugs Bunny.

[LAUGHTER]

MANOUSH ZOMORODI: I like that image, though. So we’ve mostly talked about vegetables. Can we delve into things that are a little bit dicier? Meat, for example.

We got a tweet from Aggie80– said, what do you do with meat that is freezer burned? Anything?

MADS REFSLUND: You can still use it.

MANOUSH ZOMORODI: You can?

MADS REFSLUND: Yeah. You can still use it. It’s just–

MANOUSH ZOMORODI: Is it not going to taste as good?

MADS REFSLUND: There’s not so much waste in proteins.

TAMA MATSUOKA WONG: Freezer burn is what? Just explain–

MANOUSH ZOMORODI: Freezer burn is like you take something out, and you’re like, oh my god, how long has this been in the freezer? And it has like a crust of crystals on it. And you’re thinking, this just– forget it. There’s no resurrecting this piece of meat.

TAMA MATSUOKA WONG: Why can’t you use it in a curry or something like that?

MANOUSH ZOMORODI: Use it in a curry. So just go for it, Aggie. OK. Go for it. But maybe use it in something–

MADS REFSLUND: You’re not dying of that.

MANOUSH ZOMORODI: –with more flavor.

MADS REFSLUND: I don’t think you are.

MANOUSH ZOMORODI: OK, so use more spices, maybe, to make it more flavorful? Would that be–?

TAMA MATSUOKA WONG: I don’t know what the freezer burn has done– if it’s done something with the texture or something, which it sounds like.

So if it’s done something with texture, then a slow cooking with like a robust sauce, like a stew or a curry, should not– it shouldn’t bring– you’re not slicing it really thin so that you’re trying to get a certain texture out of what you’re doing. You’re doing something that doesn’t focus on the texture of it as much.

MANOUSH ZOMORODI: OK, this is a tweet from Des. He wants to know, I have old onions that are sprouting green tails. Are they still usable?

MADS REFSLUND: I’ve used sprouted onions before.

TAMA MATSUOKA WONG: The green on the onion is not the same problem as green on the potatoes. It should be fine.

MANOUSH ZOMORODI: So just go for it. Think of yourself as having two vegetables instead of one now.

MADS REFSLUND: Exactly. It’s spring onions.

[LAUGHTER]

MANOUSH ZOMORODI: I love it. OK. This is great.

This one’s really good. From Helix, what can I do with lightly moldy bagels? I have three.

MADS REFSLUND: With what?

MANOUSH ZOMORODI: Slightly moldy bagels. I’m going to guess nothing.

MADS REFSLUND: If it’s moldy, no, I would not use it.

MANOUSH ZOMORODI: I’m sorry, Helix.

TAMA MATSUOKA WONG: I don’t know how– can you cut off the moldy, if it’s slightly?

MADS REFSLUND: But day-old bread– we have a great recipe for that.

TAMA MATSUOKA WONG: Yeah, day-old– there’s tons of day-old.

MANOUSH ZOMORODI: There’s so many good recipes. Many, many thanks to Mads Refslund, acclaimed Danish chef, now based here in New York, co-author of “Scraps, Wilt & Weeds,” along with Tama Matsuoka Wong, the fine-dining forager, his co-author.

We have an excerpt of the book and a few recipes, too. That’s up at sciencefriday.com/scraps. Check it out.

Let us know what you made in the comments or post a yummy picture on Twitter or Facebook. Sorry about the bagels.

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