huh...interesting...so it's almost like hot/cold break...strange.
Where did you come up with that ratio? 50 grams per liter? that's about HALF what you need...
Should be 1 gram DME per 10 ml water.
If you're trying to dissolve DME in cold water that's part of your problem. Boil your water first, take the bot OFF the heat and slowly stir in your DME until it dessolves, putting it back on the heat is optional IMO.