For preparing a stew, it is often recommended to marinate the meat for a long while (e.g. 24h) in wine and herbs as onions, carrots, leek. This recommendation is usually found for all meat-based recipes requiring a long, slow cooking. Sometimes a white wine is recommended, others a red one. Often the addition of vinegar is required along with wine and herbs. Why? What is the difference between using a red or a white wine, if any?
The cuts of meat used for a stew, but more in general for all meat-based recipes requiring a long cooking, are usually high in content of collagen. We find different types of collagen, but, briefly, it is a family of fibrous proteins that form the extracellular matrices. Simply, collagen is the scaffolding of our tissues. Cuts as round or round steak are very rich in collagen and, for this reason, stiff and not adequate to be grilled. On the other hand, a long, slow cooking allow denaturing collagen and, consequently, obtaining a tender meat. Actually, collagen is not the sole one responsible of meat toughness. Elastin is another protein that determines the tenderness of certain cuts. To cut a long story short, the higher the content of elastin and collagen the tougher is the meat.
How is that related to the wine marinade? It has actually been shown that marinating has a crucial role in the tenderness of meat. As usual, there are a few factors to take into consideration.
The role of wine
So, why adding wine to the marinade? This first step allows increasing the tenderness of meat. Collagen, as other proteins, reacts with the polyphenolic groups of tannins. These molecules are responsible for the coloration and the astringent taste of red wines. The interaction between collagen and tannins brings to the formation of complexes that would limit the water leakage and keep the meat juicy*. Given that tannins are commonly present in red wine (on the other hand, they are absent in the white one), we can deduct that only a red wine marinade would sort this effect. Actually, a few experiments were carried out showing that a white wine marinade does not improve the tenderness of meat.
The role of acids
The presence of acidic compounds as vinegar, helps with the tenderness as provokes the dissociation of protein complexes (and, thus, of collagen as well). Simply, you lose the meat scaffolding.
And what’s about herbs?
Unfortunately, herbs play no role in tenderizing the meat. They just help with flavouring.
In this post, I just spoke about wine and vinegar marinades. There are tons of studies on meat tenderness and on the factors affecting it. Honestly, the topic is very broad and here we have just scratched the surface, as usual ;)
Shortly, we will see how to make the perfect stew :)
*According to This, there were still experiments going on. I can’t find any recent update in the literature that would confirm this hypothesis. If you know more about that, please, let me know :)
Hervé This, Pentole e provette, 39-41, Ed. Gambero Rosso
K. Brudzynski, C. Sjaarda, L. Maldonado-Alvarez, A New Look on Protein-Polyphenol Complexation during Honey Storage: Is This a Random or Organized Event with the Help of Dirigent-Like Proteins?, 2013, PlosOne, https://doi.org/10.1371/journal.pone.0072897