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November 8, 2006 2:52 PM   Subscribe

Why does my bread become *hard* when stale, yet my crackers (graham, oreos) become *soft* when stale?
posted by 777 to Food & Drink (9 answers total) 1 user marked this as a favorite
Bread has a higher moisture content than your average indoor air, and crackers have a lower moisture content than average air. So when bread is exposed to air, it equalizes its moisture with the surrounding air and gets dryer--hard. When crackers are exposed, they equalize and get damper--soft.

Which is why the easiest way to rehydrate stale soft cookies is to toss a piece of bread in the cookie jar.
posted by hippugeek at 3:04 PM on November 8, 2006

Does the moisture difference come about simply because you use more water when you're making bread? Or is there something more complex at work?
posted by chrismear at 3:13 PM on November 8, 2006

Okay, hippugreek is close but wrong. It is the moisture, but not necessarily the moisture from the air-- although moist air can exacerbate the effect. It's the moisture in the bread itself that makes it go stale. What's really happening is that some of the chemical changes that bread undergoes when it is baked begin to reverse when it cools-- starch molecules crystalize together and push out the water that had been suspended in between them. This is why bread goes stale quicker in the fridge than on the countertop, and why microwaving stale bread can make it, briefly, soft again.

Crackers aren't as prone to this effect because they don't have much moisture in them-- it's been baked out-- and also because they have a different chemical make-up. Also, the moisture of the baked good itself isn't always all that matters-- other factors of its composition are important, too. Cake goes stale slower than bread, for instance, because the sugar in cake absorbs some of the water. A nice French baugette goes stale very quickly because it's just flour, salt, yeast and water.
posted by bookish at 3:49 PM on November 8, 2006 [2 favorites]

I'm not a scientist, and I probably could have explained that better, but that's the basic idea.
posted by bookish at 3:51 PM on November 8, 2006

It's because "stale" as you use it doesn't refer to the quality of being hard or soft, but the quality of being no longer ideal for consumption because it's past it's prime. "Stale" represents that a negative change has occurred from the baked goods original state, not what that end state is.
posted by njb at 3:58 PM on November 8, 2006

bookish is right; for a (slightly) more in depth reason see here.
posted by bluefly at 4:47 PM on November 8, 2006

The bread has become harder and the cracker has become softer but is the stale cracker softer than the stale bread? (How would you measure that?)
posted by winston at 7:19 PM on November 8, 2006

I would say fat content? I'm pretty sure we need an Alton Brown food science blogger to explain this. Crackers and cookies have far more fat in them - making them denser. Sorry, not an answer, only a hypothesis?
posted by chupwalla at 8:20 PM on November 8, 2006

It's not the fat. bookish and the information from bluefly are right.
posted by catseatcheese at 4:56 PM on November 9, 2006

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