Impossible burger

How Vegetarian Burgers Are Made to Look and Taste like Meat

There are a lot of reasons people might not eat meat, ever or at certain times in their life. Religion might be your driver or a concern for animal welfare. Others might not eat meat because of allergies, health concerns or simply because they don’t like it. A rising number of people eat less meat because of sustainability concerns. Growing animals and thus producing meat takes a lot of resources, generally more than a plant based diet. Although finding the most sustainable alternative may be quite complicated.

Especially for those of us who eat less meat by choice, it may be hard to do so if you really enjoy meat. In those cases it has proven to be quite hard to get people to eat less meat, for a variety of complicated reasons. One of those reasons is that people just really enjoy meat, the texture, the bite, the flavour. So what if you can make meat without meat?

We’ve discussed how this can work for vegetarian chicken before. But how about the ultimate fast food meat? A burger, or, more specifically, a beef based burger? It’s more challenging than you might think, let’s have a look.

What makes a burger a burger?

Developing a vegetarian burger requires in-depth understanding of what makes a burger a burger to consumers. From a technical perspective, there are a whole load of technical challenges to overcome:

  • Colour: a beef burger is red/pink when it’s raw, while you cook it, it changes colour to brown (or even black) on the outside and pink/reddish on the inside (or brown once it’s well done); remember that what people see highly impacts what people think and taste
  • Texture: cooked meat has a distinct bite to it ; a burger breaks apart quite easily into pieces, but you definitely need to chew it in order to swallow, it’s not soggy, nor starchy and the burger should hold on to enough moisture
  • Fat: you may not realize, but a tasty burger has a good amount of fat in it. The fat will ensure the burger doesn’t taste ‘dry’ and makes it ‘creamier’
  • Nutrients: a burger contains a lot of high quality proteins and red meat is a good source of iron as well as some vitamins (such as B12) ; we won’t discuss this one in any further detail
  • Taste & smell: beef meat has its own specific taste and smell, they go hand in hand, so you should have the balance of the two right

From a technical, scientist’s or engineer’s perspective, these are challenging, but interesting to try and replicate in something without any meat at all (just have a look at the list of patents below, and this is just the tip of the iceberg!)! Ethan Brown & Pat Brown (founders of Beyond Meat & Impossible Foods) thought as well. They, as well as many others, have set out on a mission to make a burger without meat and overcoming these major challenges.

Replicating the colour of beef

Beef, just like pork and other red meats, gets its red colour from a molecule called myoglobin. It can make meat anywhere from a red to purple to a brown colour. The actual colour of the mat depends on the presence or absence of oxygen. Oxygen impacts the configuration of myoglobin which in turns affects the colour of the meat.

When you cook meat, the myoglobin, which is a protein, denatures. It loses its specific arrangement with the oxygen molecule. As a result, your hamburger patty turns brown and loses its raw red colour. The protein needs to be warm enough to turn brown, so if you don’t fully cook the burger through, you will still have some of that pink/red colour on the inside. your rare / medium rare burger. When you cut into a burger like this, it will bleed slightly as well, again, a pink/reddish colour.

stew meat (runderriblappen) beef
Bright red, almost purple meat, freshly unpacked. This colour is a challenge is there’s no meat in the burger!

Non-meat based products do not contain this myoglobin and as a result don’t have this nice transition from red to brown. What’s more, if this transition is not there, how would people know whether their ‘meat’ is properly cooked? Plenty of challenges here and different companies use different strategies and not all of them even tell you what they do.

Looking for an alternative red

There are a lot of red colours in nature that you could add to a burger. Some of these are sensitive to heat (they break down when heat), others are super stable whereas again others change colour depending on the surrounding pH (acidity) of the food. To find a red that works for a burger it must:

  • Turn from red into brown upon cooking the product, it should have changed colour when it’s cooked, but not yet when it’s still not done. This is actually really challening.
  • The colour should be stable in the product during storage.
  • It should not affect the flavour of the food in a way that makes it taste less like meat.

Heme proteins

Myoglobin, the protein that gives meat its colour, belongs to the heme proteins. These proteins all have a similar structure in their molecules. This structure, in its simplest form a ring of carbons with several nitrogen atoms on the inside is called heme. Heme proteins don’t just exist in animals, they also exist in plants.

Impossible foods (see sources for patents) has found that by using such a plant based heme protein they can replicate the meat colour. They’ve even found ways for micro organisms to produce some of these, although they might not be using those currently.


When you cook a burger an internal temperature of about 55-60°C makes it medium rare. In other words, the meat isn’t raw anymore, it will be slighter firmer and have more bite to it, but still be very moist and juicy. Cook it warm to 65-75°C and you’ll end up with a burger well done. All the red/pink will be gone, but also, the burger will be drier, less juicy and firmer. The changes that you see are due to the proteins in the muscles denaturing and expelling some of their moisture.

Would you want your plant based burger to cook at the same temperatures? Most developers seem to think so, to ensure consumers really see their burger as the real thing. But that’s more challenging than you might think. Just as you had to do for colour, you have to find proteins that undergo these changes at similar temperature ranges as meat does!

Vegetarian chicken used in a fried rice dish with kroepoek
The texture of chicken is again very different from that of a burger. The dish above is fully vegetarian, but definitely has the texture of chicken!

The texture of meat

What’s more, the texture of meat is quite complex. As we discussed before when comparing meat for slow cooking vs. that for grilling a steak, meat is made up of a lot of muscles. These muscles again are made up of strands of fibers, nicely aligned alongside oneanother. This special texture is what makes meat meat and is hard to replicate (although for chicken replacers there starting to come close!). It’s the reason why many meat replacements start with burgers and sausages, since those contain minced meat. The muscles in minced meat aren’t as nicely aligned anymore as in a steak so it’s a little easier to replicate, but that doesn’t yet mean it’s easy.

Replicating the texture

To replicate this texture you have to look for proteins and carbohydrates that ‘cook’ at the required temperatures and that form gels during cooking. These ‘gels will act as the structure you need to simulate the cooking of meat. Different sources of proteins seem to work well. Proteins from corn (zein), soy or gluten for instance. Fibers from various plat types are used in different applications as well.

Non-animal fat for your veggie burger

Animal fats such as beef fat and pork fat are solid at room temperature. If they wouldn’t be, they would just flow out of your pieces of meat. Once you cook your meaty burger though, the fats warm up and they will melt. A burger needs fat to not taste dry and have a pleasant mouthfeel. Also, the fat contains a lot of the flavour of a piece of meat.

So you need a source of fat, that’s solid at room temperature, but liquid when heated in way a burger would be heated. Most plant based fats don’t meet these criteria since a lot of them (e.g. olive, sunflower, canola) are liquid at room temperature. Suitable alternative for these animals fats are often coconut or palm oils. These oils are harder at room temperature but still melt when you’d cook your burger.

Flavour & smell

Last but not least, how do you create that meat flavour and smell, without there being any meat? Well, you first have to figure out which molecules actually make meat smell and taste like meat. Once you’ve figured that out, you have to ensure they form while cooking the ‘burger’. In other words, the raw vegetarian burger shouldn’t already smell like a cooked meaty burger. Quite a challenge.

Some companies (e.g. Impossible Foods) again go back to these heme proteins for creating flavour & smell, besides just colour. When these proteins are bound with iron in a complex, they can form the desirable flavours & smells. You then should also make the environment around this protein desirable, with the right amount of moisutre for instance for the correct chemical raeciotns to occur. There definitely is a lot of engineering involved when is comes to a burger that tastes like meat, but doesn’t contain any!

Impossible burger
Yes, this is a vegetarian burger (the Impossible version). Looks pretty much like the ‘real’ thing and tasted good as well (of course the sauces, condiments and veggies helped as well).

Grow the meat without an animal

Another, very different option to making meat alternatives is to grow the meat without using an animal. This cultured meat isn’t fully vegetarian since you still need some (but way less than now) animals to supply the starting cells. From these cells researchers have now managed to grow more meat in the lab.

This lab grown burger has a longer way to go before it can be introduced into the market compared to the earlier discussed plant based alternatives (as of July-2019). However, it’s always good to explore several options, in case one of them fails, we’d want a good back up plan.

Marketing can still make it fail

Even if you’ve got the perfect vegetarian burger that looks like the ‘real’ thing you’re not guaranteed success. To make people eat the burger, they need to want to eat the burger. This is where marketing comes in and you might have noticed a whole lot of marketing of these foods all around you. Creative names for the burger that don’t explicitly mention it’s vegetarian or selling your burger through well-known chefs, all ways to try and convince people that this highly technological food (it’s probably the opposite of natural) is worthwhile to give a try, while ‘saving’ the world.

Why make a vegetarian burger that looks like a beef burger?

Of course, you can question whether we even need a vegetarian burger that looks & tastes like the real deal. It will involve a lot of engineering, science and development to make it. It’s probably less ‘natural’ than the real thing. Also, a lot of vegetarians don’t even like these burgers. It may remind them too much of meat.

That said, we (mostly American) humans have been looking for vegetarian burgers for several decades now. As early as 1901 Kellogg patented a food that could serve as a meat alternative and we have continued to work on it ever since.

There are also a lot of other ways to make a vegetarian burger of course, that still fits within a bun, but has its own unique taste. Black bean burgers are just one of the many many options out there and plenty of people truly enjoy these. Also, there are a lot of great vegetarian dishes out there already. India in and by itself has so many wonderful, vegetarian dishes that should give ample variation (what about paneer or veggie samosas?)

But there will always be people who want meat and for those who want it because of the texture and looks, these types of burgers can give them the push to eat less meat.

For any major challenge, such as this one, there is barely one solution that fits all. Instead, using several solutions in tandem, will help us all to get towards that world that we want to go to. Where there’s still enough food for everyone and one where we haven’t depleted all our natural resources.

Want to see how the Impossible burger is made? This video does a great demo, it’s really just mixing (and a little more…).


Rachel Fraser et al, Secretion of heme-containing polypeptides, patent US20170342131A1, Impossible Foods, not yet granted in July-2019, link

Rachel Fraser et al, Methods and compositions for affecting the flavor and aroma profile of consumables, pantent US9700067B2, granted 11-July-2017, link

Impossible foods, Heme & Science, visited July-2019, link

Maastricht University, Cultured Meat, visited July-2019, link

Mose Meat, The world’s first slaughter free meat, visited July-2019, link

S.P. Suman & P. Joseph, Myoglobin chemistry and meat colour, Annu. Rev. Food Sci. Technology, 2013, 4:79-99, link

Paul D Swanson, Patenting the quest for a more perfect veggie burger, 2016, link

Ranjani Varadan, et al, Ground meat replicas, patent WO2015153666A1, Impossible Foods, not yet granted in July-2019, link

Marija Vrljic et al, Methods and composition for consumables, patent US10039306B2, Impossible Foods, granted in 2018, link

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