Weyauwega Butter Creaming Experiment - Series One, Part 2

In my last post, I published the raw data from my first full series of creaming experiments with Weyauwega butter. Today I am attaching some photos. The photo of nine cookies arranged in a square is a sample cookie from each creaming time.

The creaming times in the top row are:
1 minute, 2 minutes, 3 minutes

Second row:
4 minutes, 5 minutes, 6 minutes

Third row:
8 minutes, 10 minutes, 13 minutes

The photo of cookies stacked sideways, though a bit blurry, shows the same cookies in order by time, with 1 minute creaming time at the top. They are all basically the same thickness except for the top cookie, which is a little thinner (if that is possible!)

From looking at the thickness of the cookies, you can see that the creaming time had no effect whatsoever on the final shape.

From looking at the tops of the cookies, it appears that creaming only one minute promotes pitting of the dough. Additional creaming reduces the pitting, but it never really goes away. On February 5 I posted a photo of the cookes from two batches removed from the oven 30 seconds apart. The batch removed earlier showed no pitting whatsoever, while the batch removed later showed a great deal of pitting. I consistently saw that at all creaming times. Here is the raw data from yesterday again. Notice the changes in the amount of time it took for the cookies to become "fully baked" - the "fully baked" times are the numbers on the far right, which are in minutes:

0 - NA – NA – 312 - NA
1 – 69.0 – 68.5 – 280 – 7.5
2 – 70.7 – 70.3 – 248 – 7.5
3 – 68.6 – 69.4 – 243 – 7.25
4 – 70.0 – 70.7 – 227 – 7.25
5 – 70.2 – 71.3 – 225 – 7
6 – 68.7 – 71.1 – 236 – 7
8 – 69.5 – 71.5 – 220 – 7
10 – 69.8 – 74.3 – 223 – 7.25
13 – 69.5 – 76.5 – 219 – 7.25

I should add the baking times for the cookies in the photos that were taken:

1 - 7.5
2 - 7.5
3 - 7.5
4 - 7.5
5 - 7
6 - 7
8 - 7
10 - 7
13 - 7.5


The pictures that show little pitting in general correspond to the cookies that were fully baked at an earlier point. Cookies baked longer had more pitting. The only cookies that actually seemed to show significantly more pitting than the rest were the ones after 1 minute and 13 minutes of creaming. For the other times, the amount of pitting was pretty much dependent on exactly when the pan was pulled from the oven.

I'm not sure how to interpret the decrease in baking time towards the longer baking times, and then slight increase again at the extremely long times. It's the opposite of what I'd expected - I thought having more air in the cookies might increase the baking time, not decrease it. Frankly, I can't explain why more air in the cookies decreases the baking time somewhat. I'll have to think about that one!

However, I can make up a good story to explain why baking times increase at both ends of the creaming time. :-) The observation is that the cookies whose dough got warmest during creaming because of long creaming took longer to bake than cookies with somewhat less creaming time. The weights of the 8, 10 and 13-minutes cookies were pretty similar at the end of the creaming time, but the 10- and 13-minute dough was extremely soft and gooey because it was so warm. Possibly as the warmest rolls of dough cooled, the dough collapsed somewhat almost immediately after I put the rolls on the pan so those cookies had slightly denser dough when they were put on the baking sheet than the cookies creamed an intermediate period of time; and the cookies that were creamed only one and two minutes were definitely denser, and so also baked faster. So perhaps reduced density is directly correlated with decreased baking time, despite longer baking times at both ends of the creaming time range. I'm willing to go with it for the time being. I'm not sure how to prove it, though. For now I'm content with the simple observations without drawing firm conclusions, but a tentative conclusion is, more air in the cookies decreases baking time by a small amount.

All the baked cookies are flat, though - so how could "air in the dough" affect baking times at all? Probably they don't get flat immediately. They get flat only after several minutes of baking, and before they collapse, the air in the dough does decrease the baking times. I could verify when they get flat by opening the oven during baking, but I don't care that much. :-) Once the oven door has been opened, the temperature drops and the baking time is increased, throwing off the experiment results. Too bad I don't have a glass window in the door!

The observation that the pitting was greatest with the cookies creamed at the extremes sort of fits. If the cookies creamed one minute are densest, and the cookies creamed thirteen minutes collapse in the refrigerator because the butter got warmer during the process and become more dense, then the butter is more compact at the extremes of creaming time. The butter may possibly vacate areas of the dough due to melting more quickly when it is more dense, and when it vacates an area of the dough it tends to take the flour with it and a pit in the cookie forms. That's highly conjectural, though! I can't think of a simple experiment to prove that.

Another observation related to the pitting - when the cookies are viewed from the bottom, it is obvious that there were gas bubbles in the cookies while they baked. The holes one observes in the cookies from the top are mostly where there was a large gas bubble beneath it - so big that it grew to the full height of the cookie and broke through the top. Baking powder increases the amount of gas in the cookies. Supposedly insufficient sifting of baking powder causes pitting in the cookies, and that may be a cause or partial cause, although I did sift the baking powder with the flour. A different interpretation of the gas bubbles is that the gas is initally in the dough but more dispersed, but when the butter is too dense it melts and flows downwards, and the air that is initially dispersed collects in the vacated areas, and the baking powder only adds to the amount of gas in the cookies.

I still have some analysis to add, but I'll continue in my next post. This is probably enough cogitation and shameless speculation for one night.