All grains contain peptides that mimic morphine or endogenous opioid substances. This is where I deal with my latest loaf craving. Get your bread-based exorphin fix here.

Monday, August 13, 2012

Freezing Tartine Dough

"While you sleep" Tartine Loaf

I've been noticing there is a widening credibility gap between the idea and the reality of various things that happen in life.

Return from Vacation
When I returned from vacation, as soon as I got in the door and before I was unpacked, I got a call from work.  They desperately wanted to change my schedule from working days to working nights, because no one else was available to cover a sick call.  So it goes: welcome home.

Idea: vacations are restful, a time to reduce stress and recharge your batteries.
Reality: vacations add to stress, and they poison your attitude about the work environment when you return.  After all, what have you got to look forward to, after a vacation?

I needed bread in a hurry.  I had one loaf in the freezer, which would only just get me through the weekend.  And I had to refresh my sourdough, which had been languishing in the fridge for 2 weeks.

But after the first night, I needed desperately to sleep, not fold bread every 30 minutes.  What to do, what to do?

I mixed up the Tartine recipe (my latest version of which is 100% whole wheat, 20% sourdough starter, 2% salt, 5% wheat germ, mixed all together at 80% hydration), and accomplished a mere single "stretch and turn" before placing it in a covered bowl and setting it in the fridge.  Then I slept.

the dough comes out of the fridge

beginning of bench rest

sag after 20 minutes

placed in tins -- beside reside from left-over crab-apple jelly making

I awoke about 5 1/2 hours later, divided the dough and had it do a short bench rest, even while the dough was still chilled.  I knew that the gluten in this dough was not well developed, it had not been stretched enough.  There is no way that it would stand up to being baked as a free-standing loaf, it would simply sag onto the stone.  And I wouldn't have time to bake it before my second night shift anyway.  I decided to stretch the dough as best I could and place it in an oiled tin.  

Idea  Then the idea was: send the dough back into the fridge overnight, until I could bake it the next morning.
Reality  Reality, however, showed me a different way.  The small fridge downstairs was in so desperate a need of defrosting that the door wouldn't close properly.  When I awoke I spent the late afternoon before work defrosting it.  There wasn't enough room in the upstairs' kitchen fridge for storing dough in tins, it was full of stuff left over from camping.

So the dough in tins had to sit out, covered, in the warm kitchen, until I could get the downstairs fridge defrosted.  Unfortunately, this wasn't accomplished before I had to return to work.  So the tins, which had bulk proofed only about an hour and a half, went into our freezer for the time I would be away and at work (about 14 hours, overnight).

Freeze the dough?  I wasn't sure this would work at all.

The Tradition of Frozen Dough

Frozen dough has a long tradition, in industrial settings.  It has been heavily studied by the Big Bakeries as a method of bread delivery.  Fast on the heals of the success of the Florida Citrus growers, who marketed their lowest grade oranges as 'freshly squeezed' juice in the form of frozen concentrate thereby creating demand across North America (as detailed in the book 'Squeezed: What you don't know about Orange Juice' by Alissa Hamilton), a lot of big bread companies have thought perhaps that freezing dough might be a good way to give consumers their daily "fresh" bread.  

The idea was, they would make the dough, flash freeze it, and send it in refrigerated trucks across the continent.  Point-of-sale bakeries or Consumers could pop it in the oven at the point of need, and they would have their bread "fresh" from the oven, with all the attendant scents and flavours.  

Such a thing might have military applications, too, since an army travels on its stomach.  If Julius Caesar had frozen dough, he would have been invincible. Well, Napoleon had frozen bread, but that's different.

But there were lots of problems with freezing dough.  One word that keeps popping up when one studies this is "syneresis".  Syneresis refers to the way water separates within gels when frozen.  And a frozen dough is largely starch and water -- it can be thought of as a gel, in one of its phases.  The first line of Jinhee Yi's PhD. thesis "Improving Frozen Bread Dough Quality Through Processing and Ingredients" is cautionary if not specific: "The quality of bread made from frozen dough is diminished by changes that occur during the freezing process."  You can read the entire sad story if you wish, at several hundred pages.  One fact I gleaned from skimming it: in 1990, 50% of all supermarket-bakery products were made from frozen dough.  I would like to know the stats for today's supermarket breads, I bet it is even higher -- because it is convenient for big companies to ship frozen dough to store bakeries, and the work of many scientists like Jinhee Yi have continued to improve the frozen dough delivery system.  

But it turns out that turning frozen dough into bread is anything but easy.  Freezing destroys some micro-organisms, including some strains of yeast and lactobacilli (so sourdough is going to be hit and miss).  Freezing dough causes bread to stale faster.  It changes dough strength, damaging its structure.  It decreases loaf volume.  It increases proofing time.  It negatively affects the crumb and texture of the bread.  It changes the colour of the bread, and many other organoleptic properties that we love about bread.  In short, the frozen dough people had their work cut out for them, if they were going to make this work.

One covey of scientists began working on yeast.  According to Gelinas (2009), between 1927 and 2008 there were "165 inventions on more than 337 baker's yeast strains" patented.  Part of the interest in modifying and/or selecting these many yeast strains was to solve the problem of yeast that could tolerate freezing and still create the gas that would leaven a frozen dough once thawed.  Not all yeasts were artificially genetically modified: ordinary natural selection via repetitive freezing and thawing will ultimately provide yeast strains that can tolerate this.  (Tanghe A. et al (2000) "Identification of genes responsible for improved cryoresistance in fermenting yeast cells" Int J Food Microbiol 55(1-3). pp 259-62.)

Other dens of scientists examined which types of wheat performed best when frozen (waxy wheat, a strain of almost starchless wheat, triumphed, whether or not it is the healthiest for consumers).

Early on it was determined that adding some lipids (either endogenous ones like the wheat germ I add, or exogenous ones like oil or lard) have a positive effect on staling.  Suddenly there was a rush to determine which lipids were best, for which frozen dough (Aibara, S. et al. (2005) "Microstructures of Bread Dough and the Effects of Shortening on Frozen Dough" Biosci. Biotechnol. Biochem 69(2) pp 397-402).  The longer dough is kept frozen, the more pockets of lipid molecules enlarge, such that after a month of storage, the loaf volume suffers.  And it appears that the harder the oil (the more saturated fats it contains), the better it works in frozen doughs.

Scientists like to visualize things, either from direct scanning methods, or through mathematical modelling.  It was learned that "the protein matrix of bread underwent depolymerization during storage in frozen conditions".  The gluten network itself lost water and destabilized, meaning it could not trap as much gas from the yeast.  The water was moved by the sineresis due to freezing, attracted to broken starch molecules  (Ribotta P. et al. (2001) "Effect of freezing and frozen storage of doughs on bread quality" J. Agric Food Chem. 49(2). pp. 913-8).

Mathematical models are useful to gauge how much fermentation is best for doughs, prior to being frozen. (Loveday S and WInger, R. (2007) "Mathematical model of sugar uptake in fermenting yeasted dough".  J Agric Food Chem 55(15) pp 6325-9)  It turns out that less fermentation is better, because metabolites that yeast leave behind in the dough will affect the freezing point, and ultimately the shelf life of the frozen dough.

Still other scientific clubs concentrated on which food gums would better control sineresis.  Several additives are tried: sodium alginate, xanthan, carageenan, hydroxypolymethycellulose, sodium carboxymethylcellulose, etc.  Assuming you are a major industry that supplies bread to the teaming masses, depending on what you want, you can change the ingredients, you can alter methods and through trial and error (science) you can eventually make a decent recipe.  Never mind whether it is good for consumers or whether the new creation is an improvement in taste or health-giving properties: there are chemists waiting to develop a frozen dough to your specs.   

Maybe this isn't a very generous characterization of what motivates big industry.  I mean, they are trying to supply food and sustenance cheaply to a majority of people; there could be a lot of people who went into this business to save lives, to provide affordable and convenient food.  But people with original good intentions who have made innocuous little decisions over the years in their effort to meet their goals of feeding the world's poor and hungry are today left scratching their heads: 

"It used to be that food and food makers were seen in a very positive light by consumers, health professionals and government alike.  Food consumption was seen as the solution to ensuring proper health and, indeed, over the last 100 years many diseases have been eliminated or their impact reduced simply because we have been able to improve overall nutrition.  Food and food makers were therefore seen as the good guys -- we made people healthier.  Well, as they say "that was then" -- today, I would say to you that the public, health professionals and governments no longer view us in that same light.  Food consumption is no longer seen as the solution to our health problems -- it is viewed as the cause of them.  Increasing rates of obesity, hypertension, diabetes, etc. are all being blamed on the food supply -- and thereby the makers of that food."            - Outgoing Chair of the Baking Association of Canada, Pete Plaizier, in his speech at the 16th Annual General Meeting held May 6, 2012. "A Paradigm Shift in How Consumers Think of Food" Baker's Journal, July 2012

Perhaps Plaizier is right, maybe this is a shift in paradigm for consumers.  But it is not a new paradigm for healthcare.  It is a very old idea, older than medicine itself:

Make food your medicine; make medicine your food.
- Hippocrates

Nor should it be any surprise for bakers.  This is all known.  Bakers have often taken the brunt of blame for health problems of people who eat their product -- frankly, because they have all too often tried to pass off inferior product for excellent product.  The history is there for anyone to examine.  Think "white bread".  It is why we have laws that regulate the industry.  Furthermore, this practice still goes on.  I am thinking of the way grain producers, millers and bakers market their product with extremely misleading labels.  "Whole wheat bread"?  "Unbleached flour"?  Give me a break.  That's a credibility gap that gets wider every year -- wider than the North American ass (I think Michael Pollan was the first one to put it that way).

But bakers are not alone to blame.  The other people in the food production networks are equally liable: seed developers, seed distributors, farmers, the storers and movers of grain, the millers, and on the other side of the bakers, the bread distribution networks, government regulators and ultimately the consumers.  Each has a stake in these bits of grain.  Each is trying to eke the most amount of profit from each tiny kernel.  

The Idea  We all have to start acting like we are paying attention to what we eat.
Reality  We are sold what we are told we should want.

Nobody has time to make everything from scratch.
Nobody is as interested in their food as they are in other things that give their lives meaning.
Just sayin'.

My Frozen Dough Loaf

Idea   It was to be baked with steam, covered with a roasting pan.
Reality   I took the dough out of the freezer when I got home, and left it to come to room temperature until I awoke at 1:30 pm.  The dough was in the tins, and the tins were in the roasting pan.  They don't sit very pretty in there, it is tight, and the dough rises a bit unevenly.  Can't be helped if you want to do 2 tins at a time.
I preheated the oven, and popped it in by 2 pm.  The first 20 minutes were at 450 degrees F, lid on.  When I popped the lid off, the loaves were already looking nicely tan, so I backed the temperature off to 350 degrees for the final 20 minutes.  I tested the loaf, and it appeared that this didn't bake the loaf properly all the way through.  I cranked the oven back up to 400 degrees F for another 10 minutes, but it was probably too late to give me a good finished loaf.  The uneven baking may have made the side of the loaves separate worse than they might have.

The dough wasn't well proofed, but probably was the best it was going to be in any case.  To fill 2 tins I probably need a bit more than 1000g of whole wheat to begin with.  The finished bread is a nice, soft sandwich loaf, moist and suitable for toasting.  The crust is only a tiny bit crunchy.  I like it just fine.  Tastes good (said the man jonesing for his exorphin fix).

Just out of freezer, still frozen
Should have slept a bit longer and let it proof longer?

getting some colour after 20 minutes @ 450 F., lid on

No, these are not quite done, back into the oven with you!

That's a bit better

Some problems here.

There is a significant problem with the sides of the loaf near the tin, probably indicating that there was a problem with the proofing -- I am guessing it was not long enough.   And obviously the gluten was not well developed, a true Tartine loaf will require a lot of folding and stretching, and an ordinary bread will require kneading -- none of which this dough got before baking.
Freezing didn't hurt all my yeasts, they still performed and made pockets of gas.

Crumb: This dough was frozen?
Yes: it could have been so much better.

Notes to Myself
  • It is unlikely that I will use this technique of freezing dough very often, for bread. I was driven to it here by necessity, and timing (and then decided to learn something about it). But perhaps in the future I may keep some pizza dough this way, if necessary.  I don't know. In the future, I think that adding some oil to the dough might help give it some longevity and prevent the syneresis.
  • The frozen dough turned into bread by your supermarket bakery is an inferior product to a genuine freshly baked loaf, period.  All sorts of things have been done to it to make it almost as good as fresh baked.  But it isn't.
  • It is unlikely that frozen dough will be good for very long.  Mine was only frozen half a day.  The literature I've read suggest that a lot of degradation happens, and the longer you keep dough frozen, the worse it gets.  In one of the articles it mentions that one month is an outside limit for the gluten matrix, before it is entirely worthless to keep enough gas to raise the bread.
  • The Aibara article (Aibara, S. et al. (2005) "Microstructures of Bread Dough and the Effects of Shortening on Frozen Dough" Biosci. Biotechnol. Biochem 69(2) pp 397-402) is doubly interesting because it gives a nice chart of dough's many phases -- "gas phase", "Continuous liquid phase", "Continuous protein phase", "disperse phase" etc. -- (according to the model proposed by Bloksma, 1990).

No comments:

Post a Comment