Why don't you try cooking your paste.  I like to boil mine for at least 3 minutes(it comes out like a pudding) I remove from the heat, let cool and add about 1 tsp clorox and 1 Tblsp wood glue (Elmers or PVA is fine  too)for every cup of paste.  I hope this helps. LOL Tammy

Dear Waverly, I use the boiled paste recipe because it doesn't separate. Also, I love the consistancy and the way it really softens up paper so that it 'molds' and 'shapes'  easier with less wrinkles. The mix does tend to thicken in the fridge, so I make a good batch (omitting the wood glue) about every two weeks or so. The batches I leave for the fridge contain only flour-water-salt-clorox. 

Every other day , I  puree small amounts of the chilled mix in a blender (adding water if it's too thick- I like my paste about the consistancy of pancake batter).   I don't add my wood glue until after I've pureed the chilled mix in the blender. This mix will stay outside the fridge for several days.
P.S. I forgot to mention that I always add  1/2 tsp salt per cup of pre-boiled paste. ~Tammy

The salt and clorox and wood glue in your paste keep it from spoiling quickly as well as protecting it  against mold/mildew.  The wood glue gives your finished projects strength and durability.  I've got four rambunctious boys who like to play and handle my projects- so my projects have to be as durable as possible.  As far as your pasts goes- Put about 1 liter of water into a saucepan, add about 5 heaping tblspoons of flour and 1 tsp salt.  Stir well (trying to remove any lumps). I always use a kitchen wisk to stir but a fork will also do the same job.  You must keep stirring this mixure as its heating.  Bring it to a slow boil, stirring the whole time.  You know when your paste is ready by the color change of the paste- it goes from opaque white to a clearer looking white-gray.  (I usually have to boil my paste for about 3 minutes.)   When it cools, add your clorox. 
I always make big batches of this because of the work involved.I know this sounds hard, but believe me, it is worth the effort and you only have to make this mixture about once every two weeks or so because  it stores for a long time in the fridge.  Take out small amounts of the thickened chilled paste-add water if nessessary and blend or wisk until smooth, then add your wood glue (2 TBLS for every cup of paste).  I am very miserly with my wood glue as it is very expensive here. I really hope this doesn't sound to complicated.  I've tried to be exact with the amounts I'm telling you for the recipe but I always just throw my ingredients together , adding more water to the saucepan if the paste is boiling up too thickly. Please let me know how yours comes out.
LOL~Tammy