Back in 2008, renowned Danish chef René Redzepi and restaurateur Claus Meyer, now known to foodies as the masterminds behind the four-time world’s best restaurant Noma, opened a peculiar test kitchen in Copenhagen. The Nordic Food Lab, as they called it, was a space for chefs to experiment with the weird, new, and taboo in a way they never could in a working kitchen. Ever since, they’ve scored headlines with reports on cooking with fermented grasshoppers, pheasant essence, and even beaver anal glands. But perhaps no report they’ve issued has garnered as much attention and consternation as the one released this January by then-Food Lab intern Elisabeth Paul on how to substitute blood for eggs.
Blood-based cooking has certainly been a part of Western cuisine since the time of ancient Greece, when blood sausages were mentioned in Homer’s Odyssey. And in all likelihood, people have used animal blood for sausages, soups, pastes, or drinks since the first animal slaughter. But sometime in recent history, we forgot how to use blood. The ingredient grew so taboo that even Scottish chef Nick Nairn vomited on television at the site of a bowl of cooking blood.
Yet from Scotland to Italy, Spain to Russia, and Tanzania to China, many traditional dishes still use blood. A few modern chefs have dared, in recent years, to whip up dishes like blood tarts with fig soaked in grappa and espresso, blood custard with rosemary topped with pickled pears, and blood-chocolate pudding with bing cherries. It was supposedly a blood macaroon served at the world-ranked Mugaritz in Spain that triggered the Food Lab’s interest in finding new and innovative uses for this ubiquitous but culinarily neglected slaughterhouse byproduct.
The project fell to Paul, who in 2013 spent three months testing blood—straining out the clots, studying its physical properties—until she hit upon new recipes for sponge cake, ice cream, meringue, and more, all created using blood in lieu of eggs. I recently caught up with Paul, no longer a researcher at the Food Lab, to talk about modern taboos, the health benefits of blood-cooking, and the future of blood.
How did you find the Nordic Food Lab and get involved in blood research?
We started out on a project on traditional Arctic snacks, but it was really difficult to get them tasty, because the traditional recipes were not made to be tasty. As soon as there’s seal fat included, that gets awfully difficult.
One day we had a discussion about why we have so few blood products on shelves. So we ordered six liters of blood and we started experimenting—seeing what kind of new directions blood could go as an ingredient within our kitchens. We started out with the traditional ones like pancakes and so on but then had a look at what blood actually is and how can we use it otherwise.
When and why did blood become something people were squeamish about?
Traditionally the blood was the first thing that you got from the pig. As soon as people got out of home slaughter and it got industrialized, you didn’t have the direct contact with this byproduct anymore. The abundance of blood recipes you had because you wanted to use the whole animal declined.
It’s interesting to see what a difficult status blood has right now in our daily nutrition and cooking scene because before it was a normal ingredient, and now we have a tendency towards disgust in consumers, especially when we’re talking about the younger generations.
What are we doing with blood from slaughterhouses now?
The main part of it gets separated into feed production for animals. Other parts get into different industrialized products. And a tiny little part is actually food production. It really depends on the country. Some countries have more blood sausages, and other countries have just totally abandoned the tradition. But blood recipes have been part of the food of every culture in Europe that was slaughtering pigs or cows.
You’ve tried all of the traditional blood dishes?
You get some weird things. There’s an Italian migliaccio, which is kind of seen as a dessert. It looks like a blood sausage, but you cut it into slices and it has raisins and pine nuts and it looks real dark and chocolaty. You could mistake it as a praline or truffle, but in the end it is a blood sausage, which is eaten as a treat.
We realized that there is some sweetness in the traditional recipes. From there we said, ‘if you have this, could you use it for ice cream?’ So we tried to go from the traditional to modern uses.
A lot of people think blood is going to have a very strong, harsh metallic taste.
That depends on the dish and the taster. In northern European cuisine you’d have blood sausages with a lot of spices like marjoram, and in the southern cuisine they use a lot of cinnamon and cloves and so on. So it really depends on how to cover it. We got good results from woodruff, cloves, and roasted koji as flavor components. Things like coffee or cocoa might be really good for masking the metallic taste.
During tastings, I got really different results. There was a gender and an age thing. They’ve proved already for bitter taste that it depends on your hormonal levels how you taste those components in your food, and I think something similar can be imagined for metallic taste.
It’s also about how your food or taste education has been. Have you been in contact with blood products as a child? Would you have an ethical problem with blood itself? Also, if the pig was not castrated, the hormones that you might find in some male pigs get really animalic and urine-flavored within the products.
What dishes have a strong metallic taste?
One of the more difficult ones for me was German blood sausage—not the smoked one but the one that you cook entirely and then it gets really melty in the pan. Some of these are not heavily spiced, so they’re definitely one of the ones where I myself have difficulties eating them. The metallic taste accumulates. With the ice cream you could eat quite a lot before you realized, ‘ok it has this metallic taste; it has blood in it.’ That astonished a lot of tasters.
Did your tasters know they were eating blood or did you just put something in front of them and say, ‘eat’?
We thought about it, but we thought that it was such an edgy ingredient that due to religion and ethics you should inform people first.
In choosing something like ice cream, how did you decide what to experiment with?
I first looked at the [chemical] composition of blood. I realized that it was so close to egg. So I first experimented with traditional egg recipes as an egg substitute. We did bread with blood and muffins and we tried the ice cream, which was definitely a success. Things like the sponge cake and the ice cream and the pancakes of course were the most promising recipes. In tastings, these were the favorites probably because they had less metallic aftertaste. I did tastings with meringues [mostly blood and sugar alone], flavored differently. For the ones with nutmeg and clove and cinnamon, they were perceived as edible. The others were really difficult for the people to eat. The more blood taste you have, the more hesitation.
We thought about a White Russian and then thought, ‘maybe a Red Russian is possible.’ So we mixed blood with vodka and had a try, but we only tried it once because it was such a metallic aftertaste that you can’t really imagine this as a drink.
What is the connection between blood and egg?
They both have really similar protein compositions and content. It’s about 55 grams within the serum in a serving of blood and about 60 in egg. But the really astonishing thing is that they both have the albumin protein—the serum albumin in blood and the ova albumin in egg, which have the same content and the same properties because they’re basically the same protein. So they will have the same foaming, coagulation, and emulsifying properties.
We have quite a lot of people with egg intolerance. It’s the second-biggest food intolerance in children in Europe. This is intolerance against ova albumin. If you prepare these recipes with blood instead of egg, you don’t get this kind of reaction in consumers. One hundred grams of blood has half the calories of 100 grams of egg. Another thing is the really high iron content. Anemia is one of the main nutrient deficiencies within Europe. So using blood in recipes would be a really good starting point to tackle this problem. The only problem is that with this iron being contained in the hemoglobin, you also receive the metallic aftertaste.
Aside from the metallic taste, are there any noticeable differences between eggs and blood?
The color. [Laughs.] As soon as it’s cooked it gets this really chocolaty color. Sometimes even if you didn’t add any cocoa or coffee, some people expect rich chocolate recipes when they see it and are disappointed in the end. In cooking properties, there shouldn’t be a difference in texture, for example. You might get slightly finer foam in beaten products. If you beat egg whites or blood with some sugar, the blood will be more flexible and have smaller bubbles, which contributes to the overall stability of the foam. So this might be a positive difference.
If I want to use it at home, what makes for good blood? Do some areas or animals make better blood?
Blood is quite homogenous in taste. By composition, it’s similar across different species. We tried to get blood from animals that had been raised free range. We advised people who used the recipes to look for a local source for the blood and have good product traceability. We had a lot of requests from people who found it difficult to get blood that was not already coagulated, like in Asian supermarkets, though. I didn’t realize before that it was so difficult to have a good source for it.
What’s the difference cooking with fresh versus frozen or coagulated blood?
Coagulated blood has totally different cooking properties. You can’t do this foaming that I describe in my recipes. I had no difficulty using the blood after freezing it. You just have to run it through a strainer if you have some clumps within it. But usually there’s no difference.
Do you know any chefs who are, based on your research, using blood in their cooking?
There’s a Dutch chef who sent us pictures of a meringue he made for a food festival. So there are some people trying it out. But it will be difficult to make it something for mainstream kitchens for the next decade at least.
Your work, especially the egg substitutions, got a big response. What did you make of that?
We were really surprised. At one point [during testing], amongst producers and professors, I had this nickname, ‘The Blood Lady,’ in Copenhagen. When the report came out, I was away on holiday, and I had no clue about what kind of waves followed. It was nice to see that a lot of people were interested in the ingredient. For us that showed that people get interested again in traditional products.
Now that you’re done with this research, do you want to keep on being The Blood Lady?
After this blood research, I liked my meat in restaurants well-done. For the last month, I’ve been busy with reindeer production in northern Sweden. I might get more involved in northern nomadic food production, Arctic foods, and different traditional recipes still in use within the indigenous population. So I think blood will be part of my personal cooking experience, but being The Blood Lady is a bit too much.
