So, how do marinades work? Well you might read an awful lot of web pages and recipe books that tell you that a marinade will tenderise meat. This isn’t strictly true, hitting a piece of meat with a meat hammer or rolling pin will tenderise it. Marinades do something else.
You will find in any marinade, an acidic ingredient such as vinegar, yogurt, wine, or lemon juice. This acidity softens the proteins in the meat, denatures it, makes the protein strands unwind so that the marinade can seep in and flavour the meat.
This unwinding process is relatively slow, but times vary for different meats. For instance poultry and fish rarely need more than half an hour. Other meats can take around 2 – 4 hours. But don’t make the mistake of adding too much marinade thinking it will give more flavour or work more quickly, you will just end up with a woolly coating and no extra flavour in the meat itself. A nice even, thin, layer of marinade will suffice, and give an excellent result.