I recently decided to conduct another experiment to try to make a high quality frozen Lehmann dough. The one time before that I tried this, the results were nothing to write home about. I followed all the steps that Tom Lehmann (and others) recommended to make and freeze dough, including using ice cold water and increasing the amount of yeast to compensate for the yeast that would be destroyed by freezing, but the dough ultimately yielded only a mediocre crust in comparison with a freshly baked one.
Making frozen pizza dough in a home freezer (or standalone freezer) can be a bit tricky. In fact, in an online PMQ chat in which I participated in April, and in which I raised the question with Tom Lehmann of making frozen doughs in a home freezer, he tried to discourage me from doing so and, instead, suggested that I make a frozen dough skin, dress it and then freeze the entire pizza. This was somewhat the answer I was expecting since I have read a lot of Tom’s writings and know that he favors flash (or "blast") freezing of dough, at temperatures of around –20 degrees to –35 degrees F, rather than the static freezing provided by home freezers, which he contends causes more damage to the yeast in dough than flash freezing. Nonetheless, I wanted to give static freezing another chance. I was also aware that other members have made frozen doughs with pretty good results.
For my latest frozen dough experiment, I did the following. First, I made the basic Lehmann dough in the standard way but with an emphasis on trying to keep the finished dough temperature as low as possible. In my case, I tried using frozen flour, only to discover that it doesn’t work the same way as using ice cold water. Yet I managed to get the finished dough temperature to 78.5 degrees F—below the 80-degree F that I usually strive for when making normal Lehmann doughs, and not too far off from the 65-75 degrees F that Tom Lehmann recommends for a dough to be frozen.
Second, I put the finished dough as it came off of the hook directly into the freezer, flattening it first (within a plastic storage bag) to expedite the freezing of the dough. Freezing alone, especially in a static freezing environment subject to repeated defrost cycles, is not especially good for yeast in a dough, but it is even worse if the dough is permitted to rise first before freezing. In that case, the dough effectively becomes like a porous insulator with a lot of gas, and freezing causes yeast cell walls to rupture as the water in the dough expands upon freezing. If this happens, the leavening power of the yeast is diminished because of the loss of yeast and, in addition, the ruptured yeast cells release an amino acid, namely, glutathione (aka "dead" yeast).
The glutathione has the effect of softening, or slackening, the dough to the point where its extensibility may be increased beyond what might be desired. In my case, to forestall the loss of some yeast and the production of glutathione and its potentially harmful dough softening effects, I increased the amount of yeast by about triple the normal amount I use and I lowered the hydration level of the dough from my normal 63% to 60%. (The latter change was my own idea, but I subsequently read a piece by Tom Lehmann in which he made the same suggestion.)
Third, I added some honey to the dough. The idea for this came from fellow member Les who referred me to an article that suggested that using honey at above 4% (by weight of flour) was good for frozen bread doughs, due to improvements in the rheological (deformation and flow) properties of dough. Because I am not particularly partial to sweetness in pizza crusts, I chose to stay at the lowest recommended value, 4%. The dough formulation I ended up with, for a 16-inch pizza, was as follows (with baker’s percents and gram conversions):
100%, King Arthur Sir Lancelot high-gluten flour, 12.00 ounces (340.31 g.), (1 1/2 c. plus 3 T. plus 2 t.--all level measurements)
60%, Water, 7.20 oz. (204.18 g.) (7/8 c.)
1%, Oil, 0.12 oz. (3.40 g.), (a bit less than 3/4 t.)
1.75%, Table salt, 0.21 g. (5.96 g.), (a bit over 1 t.)
0.75%, IDY, 0.09 oz. (2.55 g.), (a bit less than 7/8 t.)
4%, Honey, 0.48 oz. (13.61 g.), (a bit less than 2 t.)
Finished dough weight = 20.45 oz.
Finished dough temperature = 78.5 degrees F
Thickness factor = 0.10
The dough based on the above formulation was made in a KichenAid stand mixer, following the procedures discussed many times before on this thread. As mentioned above, the dough went immediately into the freezer, before the yeast could kick in and cause the dough to rise (it usually takes about 20 minutes or so for the yeast to start to reproduce in a meaningful way). The dough stayed in the freezer for about 10 days. Tom Lehmann usually recommends 10 days as the outside limit, but as a “fudge” factor, he will tolerate 15 days, beyond which, according to Lehmann, the dough starts to go downhill quite fast.
The frozen dough was transferred from the freezer compartment to the refrigerator compartment to “slacken out” (defrost), for about 30 hours in my case (the minimum is about 12-16 hours). During the defrost time, the dough rose hardly at all. What is important to understand about frozen doughs is that freezing compromises the flavor and other qualities of the finished crust. That is because during freezing the dough does not ferment and perform its usual functions, including the production of flavorful by-products of fermentation. Also, there is no meaningful extraction of sugars from the starch to increase the residual sugars in the dough to facilitate browning of the finished crust, or the production of carbon dioxide, alcohol, acids, etc. These start once the dough has defrosted enough to permit these activities (which will take many hours), and continue during the counter warm-up in preparation for shaping and stretching the dough.
In my case, the dough remained on my countertop at room temperature for about 3 hours before I decided to make the pizza from the dough. During that 3-hour period, the dough rose very slowly, much slower than usual. Nonetheless, I had no problems shaping and stretching the dough out to 16 inches. It was less extensible (stretchy) than usual and had a nice feel about it. I suspect that the dough could have tolerated another day in the refrigerator before using, during which time the longer fermentation would have yielded more of the desirable by-products of fermentation.
The stretched-out dough was placed on a 16-inch screen, dressed, and baked. As a departure from the usual pepperoni pizzas I make for test purposes, this time the dressing included a Muir Glen organic tomato sauce (with Penzeys pizza seasoning, fresh garlic, red pepper flakes, olive oil and grated hard Parmesan and Romano cheeses), pre-cooked Italian sausage, sautéed green peppers and mushrooms, and Kroger’s Classic Natural mozzarella cheese. The pizza was baked on the screen for about 6 minutes on the next-to-the-top oven rack position of my oven, which had been preheated to about 500-550 degrees F for about an hour, and finished by transferring the partially-baked pizza onto a pizza stone at the lowest oven rack position for about an additional minute or two to brown up the bottom of the crust.
The finished pizza is shown in the photos below. The pizza turned out quite well, much better than I expected. The rim of the crust was light and airy, and was chewy yet tender (no doubt helped by the honey). There were a few bubbles in the finished crust, which I somewhat expected because of the relatively short total 'true" fermentation time, but they were not a problem. The top crust color was also a bit lighter than I normally prefer, but I found that the Kroger Classic mozzarella cheese, which I was using for the first time, was browning faster than the cheeses I usually use and necessitated that I remove the pizza from the oven sooner than usual. With the honey in the dough, and even with diminished production of residual sugar in the dough due to reduced enzyme performance, there would have been plenty enough sugar available to promote browning had I been able to leave the pizza in the oven for another minute or so. The crust was also a bit sweeter than I prefer, but it was not a big distraction. Next time I will just use less. But overall, I would characterize my frozen dough experiment as a success and can confidently recommend it for those who wish to make frozen Lehmann dough in advance.
Peter
