Think of your last BBQ: you've probably been very careful about timing and type of meat. How about your marinade? Not much, right? The trick for a good BBQ is actually in the marinade, but marinades are good for more than just barbecues. There are two reasons for this: a marinade makes the meat tender and gives it a very refined taste. The taste is the easiest part to grasp. Marinades are made of aromas and liquids, same as vinegar and wine. When they touch the meat, these ingredients help give it a particular taste, each time different and each time delicious. To make the meat tender, you need some science. As always, we will try to make it easy to understand.
IT'S ALL ABOUT WINE...
If we start with the basics, a classic marinade is made with a combination of wine and spices. Spices give it its flavor, but we are actually more interested in wine. Wine contains alcohol, and alcohol has the ability to soften the meat (other ingredients that do that are salt, acids, glucose and amino acids). How? Altering meat's components. Meat is full of a protein called collagen, which creates its consistency. The more collagen in the meat, the more the meat will be tough. That's why meats with a lot of collagen should be cooked for a long time. The heat helps break the molecules of collagen and makes for excellent braised or boiled meats. To get a similar effect in a short time, we can use alcohol based marinades. These will break the collagen, and help keep its water, which will result in a tastier, not dry, meat.
... AND AROMAS
One of the first secrets to a perfect marinade is to mix wine with aromas. What kind of wine you may ask? Usually, and I've noticed this among my own friends, we don't really pay attention to that aspect, using either white or red at convenience. Red wine is actually better for marinades. Not for an exterior aspect, but because it contains more polyphenols. These are anti-oxidants that are actually good for you other than making the meat more tender. You've just learned the second secret: red wine, always.
AN ACID SECRET
Here we come with the third secret, an absolute trick for great meat chefs. Acids are as good as alcohol to make meat more tender. Wine is the perfect solution because it has both. However, you might not always have a very acidic wine so you might resort to some vinegar. Vinegar has acetic acid in it, same as the citric acid you find in lemons, it is very much used in cooking. We shouldn't use too much of it, or our meat won't taste so great.We can also use lemon juice, but it's not as effective and you would need large quantities. So, at this point you are only missing the aromas, and it totally depends on personal taste: of course pepper is a big one, better if fresh, juniper, sage, rosemary and sage. To these you can also add tarragon, cumin, basil, oregano, thyme. No salt, better to add it directly later, and no oil.
After you've mixed wine, acids and aromas, you only need to add the meat. For how long? A good marinade requires at least 12 to 24 hours in the fridge. The important thing is to take out the meat a couple of hours before you start cooking it. One last trick: you don't have wine or aromas in the house? You can use pineapple juice. It has to be 100% natural and is considered the best solution to soften meats without using any other ingredient. It will also taste very different and unique.