This is a semi scientific study of the effects of SAF Red Yeast compared to SAF Gold Yeast. I mixed up three types of dough at 64-65% hydration that loosely resemble the three bread types (Straight, Sour and Sweet). I know there are other flour combinations that might be interesting to experiment with but this will be a start to see if there is any difference between the standard SAF Red and the “Osmotolerant” Gold in terms of how well they work as leavening agents. King Arthur has been selling the Gold as an option for over a year and it is widely available to commercial bakeries. The company line is that the Gold is better when the dough is “Sweet” (improved with additives such as a sweetener, fat and eggs or oil). Many sweet dough recipes for example, call for more Yeast because of the negative effect of high sugar levels and spices on yeast activity. Actually KA and SAF have said little about the Gold product other than it is better for sweet dough. As a consumer I’m surprised they haven’t done some testing and marketing. That may be a message in itself.
After having used both products side by side for over a year, I decided to test the Theory that the Gold product would in fact perform better in terms of rising power over a given time. The Hypothesis being that the Gold will rise faster than the Red in the Sweet and Sour mixes. My secondary Hypothesis is that the straight dough test will show an equal rise with both types of yeast. If that secondary result is proven true, there is little need to stock 2 kinds of yeast. As it happens, I just received a fresh package of both products from King Arthur Flour last month that have been resting in the freezer which I will now open and use. So, on to the process I used.
I started by weighing out 300 grams of AP flour to which I added 6 grams of salt. I then mixed these two ingredients well and removed 6 grams of the mix to again have 300 grams of flour and salt. I set out 6 glasses and marked them for Straight, Sour, Sweet each with a red or gold marking. Then I measured 32 grams of water and 1/16 teaspoon of the respective yeast and 50 grams of flour and mixed well. Each glass was covered with plastic wrap and set aside at room temp. The water temperature was 76F for each mix.
For the sour test I used 1 Tablespoon (10g) of liquid sour that has been aging for 12 hours and an additional 3 grams flour to compensate for the additional water in the starter. This is way more starter than I would use to inoculate so little flour but it should create the environment that will make the standard yeast struggle.
The Sweet mix included 4 grams sugar, ½ teaspoon oil, 6 grams of egg and 27 grams water. I did add another 2 grams of flour to adjust the consistency to be similar to the other test samples.
Note: I don’t have a way to accurately measure the small amount of yeast so I used the best system I could think of to arrive at 1/16 tsp. First I started by measuring a ¼ tsp leveled and placing on the counter. I then drew it on the counter to a line about 3 inches long and divided it in half, twice. Each pile of grains looked to be equal in size. I understand that the scientist out there are discounting my methods as un-scientific and sloppy thus lowering the expectations for accurate results. My decision to use 1/16th of a teaspoon in 50 grams of flour is based on the scale of 1 teaspoon in 800 grams of flour. I thought the percentage of yeast was low enough to make it perform over time to develop the rise I was looking for. Let’s see what the outcome is before you hang me for witchery. At the end of the first hour they all look about the same.
Test Results: 3 Hours time elapsed
After three hours, the sweet dough shows little activity in both samples. They have expanded some and show signs of puffiness. Perhaps they have risen 20%. I’m wondering if I didn’t over do the sweetening quantities and stunted the test.
The sour dough shows the largest difference in activity between the samples. The mix with the Red is much more active than the Gold as you can see in the photo.
The Straight dough also shows better activity in the Red mix.
Note: I just realized that the labels were not all at the same level and it is affecting the visual appearance. Since I didn’t have measured beakers available, I will align the labels for the next photo
Test Results: 4 Hours elapsed
While I waited this last hour I recalculated the amounts of the additives I put into the sweet batch. The ratios I used were excessive and I believe stunted the activity in that test. I’ll redo that in the future to create a more real world scenario.
The straight dough mix with the Gold Yeast is clearly higher than the Red product. It looks like maybe 20% higher after 4 hours.
The Sour dough mix is the opposite result. The mix with the Osmotolerant yeast (gold),did not perform as well as the standard Red yeast. This is a surprise to me.
Conclusion:
I should say first that I am not a scientist. While I have tried to be as careful as possible, there are areas where even a small mistake could skew the results. I know that my sweet mix is too sweet. I added the equivalent of 5 eggs, 5 T of sugar and 2-2/3 T of oil to an 800 gram batch, which is way too much.
I decided to redo the sweet dough test alone and post everything together. I lowered the egg to 2 grams, sugar to ¼ teaspoon and oil to ¼ teaspoon in 50 grams flour and 30 grams water at 74F.
Sweet dough comparison:
The second test of the sweet formula as corrected above worked much better. As you see the SAF Red indicated by the R on the label is more active and has doubled in 3 hours. The one marked G is expanding but at a slower pace. The G would be the SAF Gold that is supposed to be designed for sweet and sour mixes.
Unless I am completely misunderstanding the purpose of the Gold product, I would say that it doesn’t seem to be working out the way it is intended.
Eric
Yeast Trial--Straight Dough G=Gold R=Red
Sour Dough Mix with a Yeast spike
Sweet Mix Redo