The Science of Marinades and Marinating, come nerd out with me.

Marinating is something me and my friends have been doing my entire life but up until now I could never really be bothered to understand what was happening, why we did it, or what would make it better.


I wanted to post a fajita steak I had made after marinating but realized that I needed to be able to talk about the marinade first, which led me to spending a ton of time sitting here pouring over research to truly understand marinades, and marinade science, like the giant nerd that I can be at times.  My goal being to be able to digest the information and regurgitate it in a  way that you, the reader, can understand the process and thus making me, the writer, seem like I know what I’m talking about.


If you’re not concerned with the details and just want a fast/clean version of the same stuff I’ve marked the cliff note version with TLDR (too long didn’t read if you’re unaware), feel free to skim through and just make mental notes.



For the rest of you, lets get our science on Mr. Tyson.

Science GIF

First things first, what is a marinade exactly?  Simple enough, its just a mix of things used to add flavor to something else.

Second things second, what exactly isnt marinade? A bit more complicated but essentially marinades are NOT something used to tenderize.  The idea of marinating to make meat more tender is a bit of a misunderstanding as brining and marinating crossed paths and got confused with each other…anyway…


Through all my research there were some universal truths I came to understand.  There are three things that all marinades have in common…they are

  1. Salt
  2. Oil
  3. Acid

That’s not to say marinades don’t contain sugars or other things but these are the holy trinity of all good marinades.



Oil serves some relatively simple purposes.  There are flavors that are only oil soluble, so you want to have oil to help act as a host for those flavors.    Also it helps when cooking the meat since you don’t need to oil the grill, or the pan, or whatever and it also just helps the marinade be thicker and stick to your meat better.


TLDR – Oil is the usher that takes you to your seat, helps everything get set up and comfortable.



Salt is a slippery slope because technically if you put a ton of salt in it and let it sit you’re brining and not marinating at this point but thats a topic for another day.  Salt is the only part of the marinade that is actually penetrating the meat.  It is the only part of the marinade that is going to do real tenderizing because salt is a smaller molecule than water which in turn allow it to actually pass through the meat.  Salt dissolves muscle protein and loosens it up.  Its not a fast process, it can take up to 24 hours for salt to penetrate even an inch of meat.


TLDR – Salt is the masseuse that actually loosens things up.



This part is hotly debated.  Acids actually denature proteins and if used too heavily or allowed to sit too long can cause you to end up with a mushy meat.  What most people agree upon however, is that acids add a very important flavor profile to the meat so even though there may be potential drawbacks, its worth using them.  It has also been found that using heavy amounts of acids can dry out the surface of the meat which can actually provide a crispier crust when flash searing, so thats something to consider in the future.


TLDR – Acid is your crazy friend that you invite to parties, they are the life of the party and you want them there, just dont let them stay too long and get out of control.





Now that that’s out of the way lets actually marinate some stuff.   This has slowly become one of my go-to recipes for a basic sweet fajita style marinade, stolen from Kenji López, it observes the basic tenants of marinating.


  • 1/2 cup soy sauce
  • 1/2 cup lime juice
  • 1/2 cup canola oil
  • 1/4 cup packed brown sugar
  • 2 teaspoons ground cumin seed
  • 2 teaspoons freshly ground black pepper
  • 1 tablespoon chili powder
  • 3 medium cloves garlic, finely minced
  • 2 pounds steak

The soy sauce functions as the salt in the equation allowing you to kill two birds with one stone, get salt in there and also impart flavor while doing it.  The lime juice is your acid.  Some basic spices and seasonings bring the flavor when melded with your oil, and the sugar allows for a bit of sweetness to come through.  If you’re looking for something more tangy/zesty then feel free to omit it the sugars or if you want to reduce the sugar content, substitute splenda.


There is no complex stuff here, mix it all together until its a nice liquid.  Cut up your meat to the sizes you’re looking for, then throw your meat in there.  I would like to note that because, even in a salty solution, it can take salt upwards of 24 hours to go as far as 1 inch into the meat, dont cut your meat up into thick slices.  Keep it under an inch.


If you threw it in a ziplock back you can just suck or squeeze some air out and you’re good.  For those of you using a vacuum sealer like me you may want to use the counter-trick to avoid getting tons of liquid into your sealer.

Basically just hang the marinade and meat off the edge of the counter.  Hit the vacuum/seal button and once the liquid starts creeping up the top of the bag, hit the seal button before it rushes into the machine.




Bam, you got your marinade.  Take note of the liquid creep.


Thats honestly it, I know that was a bit long winded and complex.  The actual cooking of the meat is another post entirely but at least now I have something I can reference when talking about marinating.


I hope you got your fill of science.