The effect of scoring on loaf shape.
We have had a number of discussions of baking techniques that impact oven spring and how well our cuts bloom. These have mostly focused on oven/stone temperature and oven humidity.
Michael Suas, in his book "Advanced Bread & Pastry," provides some information about how scoring patterns influence loaf shape. Scoring is not just to make a visually pretty design on the top of a loaf. It is also a way for the baker to control the direction in which the loaf expands. This impacts the shape of the loaf cross section (rounder or more oval), the hight of the loaf and, for a boule, whether it stays round or ends up more oblong.
According to Suas, long loaves like bâtards and baguettes are traditionally scored parallel to their long axis. This may be a single long cut or multiple cuts that are almost parallel and overlap somewhat.
The effect of these cuts is to allow the loaf to expand in width, resulting in a more oval cross section.
However, for breads with high-rye content which have lower gluten and less oven spring, the traditional objective is to encourage a higher rise in the oven spring resulting in a rounder cross section. This is achieved by "sausage" or "chevron" cuts.
Sausage cut (on the left) and Chevron cut (on the right)
Boules are scored in a variety of patterns, again with differing effects on how the loaf expands. The common "tic-tac-toe" pattern and a simple cross will direct the expansion upward. More complex patterns like diamonds result in a relatively flatter loaf.
One of most interesting effects is that scoring a boule with multiple parallel cuts encourages expansion at a right angle to the cuts. This results in an oblong loaf shape.
Two identical boules scored differently
Of course, there are other important variables in scoring such as the cut depth and the angle at which the blade is held.
Your comments are invited.