It will only fail, if you try an invalid combination, what exactly do you combine? If two small poison bottles, it should give you one medium, if you combine two medium, it should give you one large, if you then combine two large, you should get one Giant Poison bottle (same with healing potions). Once you craft any of this, it should get into the recipe list, then you should be able to craft from there directly. Recipes never fail, unless you don't have the numbers of ingredients needed, then it should be greyed out. I don't really know, where's the issue.
I use the ooze barrel to create 20 or more small bottles of potion.
That recipe never shows up in the recipe list with the ooze barrel.
What makes it worse is that say I now have 20 small bottles of poison. I can't split it and have 10 and 10 and then combine those 10 and 10 to make 5 mediums. I have to split the 20 into single bottles. Again this never shows in the recipe list.
