I hope my readers will pardon the inside joke of the title of this particular blog entry. A couple of years ago around this time of year I wrote a blog entry on the three types of leavening , and it has since become one of my most popular blog entries, and (ironically enough) one of my more controversial ones. The reason for this is that while it is easy for people who seek to avoid leavening during the Days of Unleavened Bread to recognize how biological leavening and chemical leavening work and to avoid them (since both of these types of leavening show up on the ingredients list of a food and can allow us to toss out or use up an item that contains Sodium Bicarbonate or Calcium Phosphate and Cream of Tartar or yeast), it is difficult for people to recognize how mechanical leavening works.
Several times I have received questions on mechanical leavening, on what it means and on how it works. It is my hope that this particular entry will answer at least some of those questions and provoke some further discussion and thought on the matter. In examining mechanical leavening we have to leave behind ingredients and start to examine processes, and in examining the subject of mechanical leavening, we can find some intriguing insights into the symbolism of the Days of Unleavened Bread. It is my hope to point out at least some of those implications.
First, let us examine what mechanical leavening is. According to Pastry Scooop, mechanical leavening is “a process that uses steam, trapped air, and boiling fats to raise a dough or batter.” Examples of this would include such foods as puff pastries and some butter cakes . In his examination of mechanical leavening, Joe Pastry  points out a few of the distinctive qualities of mechanical leavening–no microbe or chemical is the starter for the rising of the bread, intense effort is necessary to get the steam to rise the air itself, the fact that the process of leavening the bread is so involved makes it a much rarer type of leavening than its more easygoing chemical and biological relatives. Another insight provided by Joe Pastry that helps to explain matters is that steam is what is responsible for the rising of bread anyway. Whether bread rises by the action of a microbe, by the steam that is given off through the heat of cheical reactions, or through intense human effort, the end result is leavening. And, in the context of the Days of Unleavened Bread, that leavening is symbolic of sin.
All too often our focus is on ingredients and not processes when we are preparing for the Days of Unleavened Bread. So long as we are sufficiently inclined to desire to put out leavening from our lives, we can look at a box of bread products and see whether yeast or chemicals have been added to it. But this focus tends to obscure the real culprit of leavening. The yeast or the chemical is merely the agent for the operation of steam, which is what causes the bread to rise and the increase of space when something puffs up. Too often we focus on the agent of leavening as an ingredient (to the exclusion of processes) and too often we fix our attention on the agent itself rather than examine leavening in its larger context. In so doing, we fail to gain a great deal of possible insight when it comes to sin and its effect on us.
For example, many people like to furiously deleaven their houses in preparation for the Days of Unleavened Bread. At times, this deleavening process can take weeks (or even months), with the person seeking to remove every possible crumb from a house, to make sure that no leavening remains. Such people, of course, may not be aware that leavening remains in the air, since yeast particles in the air would enter a house whenever the door is open or closed, nor would they see that it is not leavening agents that are symbolic of sin, but rather leavened bread. Leavened grape juice (we call it wine) is not considered a prohibited item during this particular time.
There are, of course, some obvious questions as to why. When bread dough is leavened, by whatever means, the steam rising in the bread makes the bread start to spoil. Unleavened bread or its constituent components of wheat and oats and barley and rice and other related grains, can keep for a long time so long as they are kept dry. But leavened bread does not keep for long before it starts to become corrupted. It is the corruption of leavened bread that makes it a particularly potent symbol of sin, the fact that while unleavened bread has a long life, leavened bread has a much shorter symbolic shelf life, reminding us of the connection between sin and death. It is the symbolic meaning in this case that allows us to see grafically and visually how sin corrupts us spiritually and metaphorically. In contrast, unlike beer (a bread product formed by biological leavening), wine keeps for an incredibly long time, as do other distilled liquors. It is the fact that the processes that make wine do not make grapes spoil, but rather can last for a long time, makes wine an inappropriate symbol for sin.
Curiously enough, those people who oppose even the moderate use of alcohol kept within strict limits tend to focus on the role of wine and other substances as a possible agent of sin in their condemnation of sin. We may look at the three types of leavening as symbolic of three different ways that our lives can manifest the effects of sin. Biological leavening reminds us that we live in a corrupt world where evil influences are all around us. Chemical leavening reminds us that the substances we take into ourselves can lead us into sin and corruption. Most of us are sufficiently sensitive to recognize the sinful results of outside influence and chemistry on our lives. However, mechanical leavening reminds us that our own activity can stir up sin in ourselves and others, and that sin is not merely an external ingredient that can be read on a label, but it is also an aspect of processes and behaviors that stir up trouble. Recognizing that bread can become puffed up and leavened by stirring up, in the absence of external chemicals and yeast, is a reminder for us to examine our own internal processes of behavior and not merely external influences.
In my life, I have stirred up a fair amount of trouble for myself and others. Most of this trouble has been stirred up rather unintentionally, but being a person of routine and pattern, I have generally been able to recognize patterns of behavior that stirred up trouble. Included in these patterns of behavior were certain habits of stirred up and fierce speech, a desire for self-justification, a tendency to respond rather quickly to the perceived slights of others, and other related actions. I have seen plenty of these actions and patterns of behavior in myself as well as others, and the presence of these patterns of behavior generally and quickly leads to a decline in civility and respect and to hostile speech and action that is sinful. We can all stir up evil works on our own without the presence of external stimuli to sin–if we rid our world of evil influences and mind-affecting chemicals, we would still have our own sinful patterns of human behavior to wrestle with, patterns that have been modeled by example from our parents and other authorities, or that we have picked up in our own experimentation with sin. Before we can be unleavened, we must wrestle with our own behaviors as well, and recognize that we too are agents of corruption and leavening through our (occasionally) corrupt conduct.
Accepting this responsibility can be an immensely liberating process. Instead of placing the responsibility of sin merely on external facets and ingredience, it allows us to focus on the sin and corruption that occurs through patterns and processes of behavior, both within ourselves and others. By studying these patterns of behavior and bringing them under the control of God’s Spirit and in line with God’s ways, we can find ourselves being an edifying and encouraging factor in the lives of others rather than a corrupting agent. If our attention is drawn to the reasoning behind why leavened bread is so symbolic of sin (and its end result–death), we can examine whether our preparation for the Days of Unleavened Bread leads us to focus on processes and behaviors in ourselves and others through self-examination and reflection or whether our concern is merely on ingredients and externals without dealing with our own culpability in the spread of sin through families and institutions and relationships. Let us therefore resolve to stir up good works in others, rather than stir up sins through our habits and behaviors.