ceed <ce...@is.indeed.invalid> wrote in
news:op.wcgcx...@hit-nxdomain.opendns.com:
When do you see the collapse? Is it that the loaf doeasn't rise in the
center, or does the loaf look all right after baking and then sag in the
center? The timing of the collapse can hint at the cause.
The holes in the top being larger than the holes in the bottom is normal.
Think of the weight of the dough bearing down on teh poor little yeasties
and the gas that they produce. If there is a lot of pressure, then the gas
will be relatively compressed and will have a hard time expanding. That's
the case at the bottom. On the other hand, the guys at the top have
nothing to impede their development, so they can go wild. The result is
larger holes at the top of the loaf than at the bottom. This is normal in
all breads.
The countermeasure is to flip the loaf 15 minutes prior to baking, which
gives a chance for things to sort of even out.
A flying crust (tunnel crust), a topic of much debate on the board, is
another thing entirely.
The flying crust is the result of several things.
1. Over proofing. The loaf expands, then the yeast runs out of energy
(food) and stops expanding.
2. The crust has been allowed to dry out a bit, becoming a bit hard.
3. The interior of the loaf collapses, but the crust is now dry, so it
doesn't fall back (collapse) with the center, which leaves a hole between
the crust and the crumb.
4. The unwitting baker then bakes the loaf. The crust bakes up nicely,
but the crumb, having run out of energy and fallen, doesn't rise very much,
which leaves a hole under the crust down the center of the loaf -- a
tunnel.
If the loaf collapses during baking, that means that it isn't getting
enough energy to raise the crust up. This may be caused by too long a
proof. This gets my vote as the problem here. You may also have used weak
flour -- all purpose or cake flour instead of bread flour, although one can
make excellent bread with all purpose flour, it just takes a bit of
thought.
If the loaf collapses after baking, i.e., during cooling, that may indicate
that the loaf is underbaked, the crumb hasn't baked fully, leaving a bit of
damp crumb, which hasn't baked fully and thus can't support the crust.
Assuming a 48 ounce loaf of 30 ounces of flour (60% hydration), the 0.3
ounces is 1% yeast, which should be okay for a normal loaf. (However, if
the dough has oil, fat or a lot of sugar in it, you could need as much as
3% yeast; if it has a lot of whole wheat, you may need 1 1/2 to 2% yeast.)
Cutting the amount of yeast may be a way of cutting proofing time in a
fixed-clock-time machine -- in a machine where you have no option but to
turn it on and let it rip.
I would cut the water a bit and make sure that I had good quality flour,
bread flour if you can. If you can shorten the proofing time, that's good
too. One way to do this might be to start with cold water, but that's not
very precise; what that would do is delay or retard the initial acitvity of
the yeast. Yeast doubling time is 1 1/2 - 2 hours at optimum temperature,
which is 28C, or 82F. It slows at higher and lower temperatures, and at
57F it takes four times as long to produce a generation, double. So if the
yeast stays active for 2 hours, there are twice as many of the little guys
and gals breathing and putting out CO2 as there were at the beginning.
This is what gives rise to bread. If you retard the initial recovery from
the lag phase, the first few minutes of the process, then you lengthen the
time that it takes the yeast to double, which reduces the amount of gas
produced but also assures that the yeast doesn't exhaust its food supply.
and can still produce gas into the baking time, oven spring.
What proportion of salt are you using? It should be something around 1.8
to 2% of the weight of flour, or between 1/2 and 5/8 ounce for a 30 ounces
of flour loaf. I doubt salt is the problem, but it's best to check.
Sorry for the long answer, but this is an interesting problem, something
that may have several causes, all interacting.
Cheers,
Barry