
Parbaking

Parbaking is a cooking technique in which a bread or dough product is partially baked and then rapidly frozen for storage. The raw dough is baked normally, but halted at about 80% of the normal cooking time, when it is rapidly cooled and frozen. The partial cooking kills the yeast in the bread mixture, and sets the internal structure of the proteins and starches (the spongy texture of the bread), so that the inside is sterile and stable, but the loaf has not generated "crust" or other externally desirable qualities that are difficult to preserve once fully cooked. 
A parbaked loaf of semi-cooked bread is in a form that is relatively stable against aging. It can be transported easily, and stored until needed. Parbaked loaves are kept in sealed containers that prevent moisture loss. They are also usually frozen. A parbaked loaf appears as a risen loaf of bread, with much of the firmness of a finished loaf, but without a browned or golden crust (in the case of a normally light colored bread). It does not age or become stale like a fully baked loaf of bread.
When the final bread product is desired, a parbaked loaf is "finished off" by baking it at normal temperatures for an additional 10 to 15 minutes. The exact time must be determined by testing, and varies by the product. The final bread is then often indistinguishable from freshly baked bread. 
Effect on cost and supply of bread.
Parbaking has shifted the economics of freshly baked bread. Parbaking allows manufacturers of bread to prepare, and then distribute bread to a market far beyond the geographic limits of conventional fresh bread. In the past, the roughly one day expiration period of freshly baked bread limited the reach of small bakeries to a local market. Significant transport times would waste too much of the bread's useful life. However, with a parbaked product that is frozen until final baking, a bakery can supply distant outlets with breads ready for baking on demand.
Parbaking can save costs for many parties that distribute bread. The source bakery benefits because it can sell to more customers: The range of its breads are no longer limited by an expiration date. More varieties of bread can be produced for this larger market, because much less will expire in transit. The product is not wasted if unconsumed, so less-popular specialized breads can be delivered. Also, commercial buyers can buy larger quantities without fear of expiration. Since most of the baking occurs at the source bakery, the source bakery can also assure that their branded product will reach consumers in peak quality. Parbaking has enabled national bakery brands distributed in either supermarkets and branded retail shops. Some examples include Brioches la Boulangere in France; Signature Breads in the United States; and Tim Hortons in Canada.
Supermarkets (secondary distributors) also benefit, because parbaking lets them reduce the need for skilled bakers in their stores. Only a simple finishing bake is needed, so simple instructions and baking times are easy for untrained store personnel. Instead of a complex bakery with specialized equipment, only a simple oven is needed. Also, bread is baked only when it is needed. As bread sells out through the day, more can be baked. 
The consumer benefits, because freshly baked bread is available in markets where it may not have previously been available due to geography or other causes. Thus, small towns without specialty bakeries can benefit. 
On the other hand, parbaked bread may have some differences from the standard baked product. Additives may be used to modify the flour and dough composition to be suitable for the process. Yeast may be added in quantities other than usual to create breads of the same size but more air content and less dough. Also, the bake-off product may harden more quickly than a standard baked bread or roll.
The parbaking technique may upset the dynamic of the local "artisanal" producer if one already exists in a neighborhood. If parbaked bread is introduced to consumers previously accustomed to such local products, and if the new parbaked product is equally palatable, and available at lower cost (due to efficiencies achieved by mass distribution), the local producer may be at a disadvantage.