So I work in the Drilling Fluids industry and work with Caustic (sodium hydroxide) and Phenolphthalein on a daily basis. I need to start checking my acid on my wines. When you ordered the test kit (they want 20buks for shipping to AK) they use .1N sodium hydroxide. So to mix my own I would use 4g/100ml for 1N. Does .4g/100ml sound alittle low to anyone else? All the test kits I looked at online said its .1N is that correct. Thats hardly any sodium hydroxide for 100ml of DI H2O. Is this just a very weak caustic solution?