In Reply 1636 at http://www.pizzamaking.com/forum/index.php/topic,3940.msg180427.html#msg180427
, I mentioned that I was going to repeat the oil/gluten test described in that post to be sure that I did not make an error when I was able to retrieve only 1.3 grams of oil from the 2.09 grams of oil that I had used in the test dough. That test dough formulation that I used for the last two tests is shown below. As will be noted there, the dough contained only flour, water and oil. I adjusted the percent of oil so that it was 2.09 grams, as was also the case with the previous tests along the same lines. The combined oil/gluten mass test was conducted in the same manner as the previous test. Test Dough Ball with Only Flour, Water and Oil
|King Arthur Bread Flour (100%):|
Water (Spring Water) (55%):
Vegetable (Soybean) Oil (2.32%):
|90.1 g | 3.18 oz | 0.2 lbs|
49.56 g | 1.75 oz | 0.11 lbs
2.09 g | 0.07 oz | 0 lbs | 0.46 tsp | 0.15 tbsp
141.75 g | 5 oz | 0.31 lbs | TF = N/A
The results of the repeat test were essentially the same as the previous test. That is, I again retrieved about 1.3 grams of oil from the 2.09 grams of oil I used in the test dough. Not knowing quite what to make of the test results, apart from the difficulty in trying to retrieve 2.09 grams of oil from over 600 grams of material, I decided to do another test. For this test, I took the contents of the small drinking glass with the starch and other sediments in it and poured it into a taller drinking glass. I then added more water to it, along with 13 grams of oil (about 2 7/8 teaspoons), and thoroughly mixed all of the ingredients together. I intentionally used a lot more oil just to make the results more dramatic and easier to interpret.
I then let the ingredients in the glass sit for about 1 1/2 hours to let all of the solids settle out. I wanted to see how much of the oil would rise to the top of the glass and whether any of it would be trapped in the sediment material (mostly starch and maybe some soluble protein, etc.). As soon as I finished stirring the contents of the glass, I saw that some of the oil immediately rose to the top. After the rest period, I put the glass back into the freezer. The following morning, I saw that some of the oil was congealed on the top and edges of the ice but after only a few minutes at room temperature, it started to flow. Over the next 20 minutes or so, I gradually let the oil and water from the defrosting ice drip into a metal lid (I used a 3" metal lid this time). When I saw that some of the starches reached the top of the defrosting ice and wanted to drip into the metal lid, I stopped the process.
I then put the metal lid with the oil and water into my countertop toaster oven and let the mixture heat up at around 212 degrees F. It took a considerable amount of time--over two hours--to drive out the water. One of the things I noticed is that when oil is heated, it thins out, making it difficult to distinguish it from the water, both in consistency and color. However, I noticed that there was bubbling in the mixture, which I took as water being driven out of the mixture. When it appeared that the bubbling had stopped, I let the mixture cool down and weighed it. It was a bit over 13 grams. However, I noticed that there was still a bit of oil on the top of the water in the glass (by this time, a good amount of the ice had defrosted). I scooped out the oil and water at the surface using a spoon and put that back into the metal lid and back into the toaster oven. After the water was driven out of the mixture, I ended up with about 0.4 grams of additional oil, for a total of about 13.6 grams. I suspect that there was perhaps some water left in the mixture but I did not have the time to finish the exercise, and hence I ended the test. For the record, the oil tasted like oil and it was not salty (which made sense since there was no salt in the test dough).
So, what do all of the oil tests tell us? First, it appears that oil in a mixture with water will rise to the top of the container, although it may take some time for all or most of the oil to do so. and it may happen after the mixture is put into the freezer. Second, if there is molasses, yeast and/or salt in the dough, it appears that some small but indeterminate amount of those ingredients will end up in the oil, and will be reflected in the color and/or taste of the oil mass. Third, it is a real challenge to try to retrieve a very small amount of oil (2.09 grams in our case) from a large amount of material (over 600 grams in our case). Fourth, the oil test takes a lot of time to conduct, with a lot of "waiting around" and "standing around" time to carefully perform all of the steps required to conduct the test.
So, it is fair to ask, is it worth conducting the oil test? My view on this is that if one has a sample of a real dough, such as a real MM dough in our case, that can be sacrificed to perform the oil test, I think it is worth doing. What I would be looking for in such a test is a general idea as to how much oil is in the dough, even if the number is not exact. So, for example, if someone did an oil test using five ounces of a real MM dough and told me how much oil was extracted, I think I would be able to get a pretty good idea as to whether our estimate of the amount of oil is in the ballpark. I might also remind ourselves that the oil test is conducted at the same time as the gluten mass test. That is, both tests are conducted on the same piece of dough. So, if you are going to do the gluten mass test and can spare the time, you may as well do the oil test too.
As for the gluten mass part of the overall test, I ended up with 49.2 grams, or 1.74 ounces. When I extrapolated that amount on paper to 6 ounces of flour, which is what you have been using for the gluten mass tests, the amount of gluten was 92.89 grams, or 3.28 ounces. That is a bit higher than the last tests, but still in the bread flour category. Also, as with the prior gluten mass tests using the small test dough balls, the gluten mass numbers are extrapolated numbers, not actual numbers.