# Isn't moisture a problem when measuring flour by weight?

Is it okay to measure flour by weight by converting from volume?

The choice of measuring by volume and weight is discussed. I've always preferred weight, but have a lingering feeling of an additional error that is more prevalent when measuring by weight, namely any amount of moisture content in the flour.

Say, perfectly dry flour has a certain density d.

The flour that has a "maximum moisture content", have certain percentage flour, and a new density d_2. These two numbers conspire to change both the volume and weight measurments.

"Maximum moisture content" means "not obvious", I guess.

Are there any known results of this kind? How much more/less moisture may exist in the flour without being noticable?

To further complicate matters, I guess it also means that any added water should take that extra moisture into account?

I'm thinking of the similar discussion of mushrooms; weight vs volume, which always claims weight is better - to which I disagree; just think of dried mushrooms, at a fraction of the initial weight. Of course a powder isn't the same as a mushroom with cell walls, but I guess as single flour particle could absorb moisture anyway?

• I'm having a hard time figuring out what your question actually is @NiklasJ. Are you asking how much moisture is typically present in flour? Or how much water flour may absorb over time? It's just not clear.
– GdD
Jan 29, 2018 at 13:33
• I don't have any citations to give so I'm not making this an answer, but I would assume that the variation in the weight of flour through moisture content, below a level where flour would appear damp and you would probably opt not to use it,would be minimal. I certainly can't imagine that the variation would be greater than the margin of accuracy of most kitchen scales for domestic baking amounts. Jan 29, 2018 at 13:36
• @GdD I've updated the question, perhaps clearer now? Jan 29, 2018 at 13:47
• You could test the hypothesis yourself by weighing out two equal quantities of flour and placing one in the oven for 4 or 5 hours at about 103° C. Then weigh the oven-dried sample again and see if it is significantly lighter. (that is broadly the method used by The American Association of Cereal Chemists, apparently. archive.org/stream/cu31924003565326/cu31924003565326_djvu.txt my own guess is that domestic kitchen scales are unlikely to be sensitive enough to detect a difference. Jan 29, 2018 at 13:53
• So you're asking whether absorbed moisture changes weight or volume measurements more?
– GdD
Jan 29, 2018 at 13:53