That is a low relative humidity, although one has to consider the absolute humidity if you're dealing with refrigeration. The higher the temperature the bigger the divergence between relative and absolute humidity, so if it's very hot there might still be enough moisture in the air for it to get drawn into a cold hygroscopic solvent. This is something that can be looked up and/or calculated (i.e. the relative humidity at different temperatures for the same absolute humidity).
Evaporation of a liquid residue would present a likelihood of excess citric acid remaining in the product, which in turn would skew yield and dosage calculations. The EA rinses would clear this up. There are some current threads that go into sufficient detail regarding attempts to resolve CIELO goo.
But first of all, you'd best ascertain what physical state the precipitated material is in before going too far up the garden path (although the background reading would likely be at least educational even if not immediately useful). And yes - should the need arise, anhydrous magnesium sulfate will dry your EA. And if a less-than-complete dryness would be acceptable you can even soak up a small amount of excess moisture from a solvent with the use of salt (NaCl) that has been dried in the oven.
βThere is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
β Jacques Bergier, quoting Fulcanelli