A lot of recipies call for marinades of one kind or another, and then say leave in the marinade overnight or or a few hours. When I have used marinades they seem to change the texture of the meat and I end up with portions of the Que soft, almost mushy and not at all appealing.
I asume I need a shorter time "in the bag" but how do you know whats the best technique?
Comments
Yes, if it's mushy, it marinated for too long with the recipe used. Acid marinating will begin to break-down meat fibers given enough time for the pH level (acidity) of the solution. We use marinades to impart flavor to meats and/or vegetables, as well as to tenderize meats...tenderizing is faster with reduced pH (increased acidity) marinade recipes, but this also carries a higher risk for destroying the surface tissues of the meat. BTW, to answer your question, surface color change of the meat over time is a good indicator to the marinating process, so note the color immediately after applying marinade, then, monitor for change...it will begin to turn grey as the marinating progresses...time for color change can give a rudimentary indication of the acidity, as well as the length of time to leave in the marinade.
There certainly is some science behind proper marinating. The pH level, or degree of acidity plays a major role in marination of meats and vegetables, coupled with the time that the food is exposed to the marinade solution or media. The lower the pH level of the marinade, the less time is required for marinating. Finding a balance of time vs acidity, being the key. So, you may ask, how do I find out what the pH level for a particular marinade recipe is, and how much time to marinate based on a given pH?
To make a marinade work properly, you first need to understand what components reduce the pH level (increase the acidity). Here's a list containing sub-acidic, acidic and alkaline foods, which will help to determine what foods or juices will aid in marination, as well as those which are neutral and those which are alkaline:
http://internethealthlibrary.com/DietandLifestyle/fruit-classification-chart.htm
Here is a useful list to determine the actual acidity level (pH) of certain food items (pre-blending of marinade solution), listed by food type, then, alphabetical order:
http://www.fda.gov/Food/FoodSafety/...thogensNaturalToxins/BadBugBook/ucm122561.htm
To develop a good basic marinating recipe, some trials would be needed in order to determine how much time you need to marinate your foods in order to achieve the results you want with a specific species, size/type of the cut of meat (examples: shoulder, chop, sirloin roast, flank steak, loin), or type and size of vegetable, as well as the cooking process utilized for that particular food (low and slow, seared, steamed, etc). My personal experience has been that for any low and slow cooking, marinating will take on part of the role of the cooking in regard to tenderizing the meat, so results may be less desirable or noticeable, while with faster cooking processes, the meat can benefit much more from marinating.
For the purpose of a good baseline starting point, I would suggest that you acquire a pH test strip kit (not the types for urine or saliva testing...pH range is too narrow), or learn to calculate by rule of averages as I'll discuss a bit more below. Test strips can be used in the absence of fats or cooking oils only, as the oils may prevent water-solubles from contacting and reacting with the chemicals on the surface of the paper. Without a way to test the pH, you will need to follow a series of trial and error tests, and if you change any components in the marinade, you effectively change the pH value as well. If you test the actual pH of a prepared marinade, you will have a known value to begin the process.
What is a good baseline marinade pH value and marinating time? I would suggest you start with a pH of 4.2-4.6 for small cuts of meat (3/4" or less in thickness) and anywhere from 30 minutes to 3 hours marinating time, depending on the thickness of the cut of meat and amount of tenderizing you wish to achieve. I read something a while back about a 4.2 pH as a baseline for a study done in a meat lab for marinated chicken breast...if I can find that page again, I'll post the link. For larger/thicker cuts with less surface area/lb, use a higher pH value (reduced acidity) and longer marinating time to allow for slightly increased penetration with reduced reaction to the surface meat tissues over the extended time period. Marinating very thick cuts of meat will yield less desirable results, with tenderizing being only a very small fraction of the overall thickness, and increasing the possibility of damage to the surface tissues. This is when you will experience mushy cooked meats, as well.
Can I formulate an approximate pH value for a marinade without using a pH testing method? Yes. If you use the pH value chart above for the marinade ingredients you will be using, by the rule of averages, given the measures of each ingredient and their corresponding pH value. To achieve a reasonable degree of accuracy, you need to average all ingredients, by weight. To achieve the desire pH value, you can add or subtract ingredients or quantities.
As I'm sure you are probably thinking by now, yes, there is a lot more to marinating then just tossing some citrus fruit juice into a bowl with some herbs and spices and pouring it over the meat. You can make a marinade too weak or too strong for a given application. With a little forethought and a basic understanding of how it works, you can make marinades that will make your food sing. Do you have to know the pH value for your marinade? No. Do you need to experiment to find what you will like best for a certain food? Yes.
I haven't gone through all the trouble to make a marinade recipe based on pH level myself, though I do not marinade very often. Now that you have brought it up, and I took the time to really dig into the subject, I just may try it. I have industrial pH test strips, and I also have a calculator, pen and paper, so, either method to reach an approx. pH level is possible for me.
Eric
