Why are 'table salt and sugar are both terrible candidates for recrystallization'?

I received a comment on one of my other chemistry [question](https://chemistry.stackexchange.com/questions/60323/why-add-specifically-hot-solvent-during-recrystallization-procedures-instead-of)s stating that



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> table salt and sugar are both terrible candidates for recrystallization, albeit for different reasons.
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Why are salt and sugar terrible candidates for recrystallization?




The solubility of $\ce{NaCl}$ has very poor temperature dependency. If you dissolve it at $100^\circ\rm C$ and precipitate at $20^\circ\rm C$, you'll essentially lose about 35 g to purify 3 g. Even using a fridge, you'll still lose more than half of the product, which is quite a bad business. Industrial process relies on evaporation, I think.


Sugar is another story. It does have a nice temperature dependence, but it dissolves too well, even when cold. Just imagine dealing with that awfully viscous syrup, like molasses. It would take *forever* to filter, and quite a while to crystallize. Industry can handle that, but for home chemistry I'd suggest something more pleasant.


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