No I'm not crazy. Okay maybe a little. I can’t really say I’m ever a very environmentally conscious person. I will try not waste anything but I also use disposable items for daily life and for crafting. However, I came across a thread about using rancid oil for soap which really intrigued me. The thread is https://www.soapmakingforum.com/threads/quick-question-stale-oil.35257/ I was reading an article yesterday on how the cooking oils we disposed through our sinks could accumulate into fatbergs in the sewer system which could potentially pollute out water. You could search “fatberg” in wikipedia and see what it's about. As someone who lives in a crowded city that has an abundant water resource but less than enough clean water resource, this got me thinking. Now, I don’t use a lot of oil in my cooking,usually a 250ml bottle can last me at least a whole year so this didn’t concern me too much at first. However, as the Chinese new year was around the corner (this Friday! Wooo!), I like to make spring rolls as a holiday tradition which are cooked through frying. That will be quite some oil. I use either rapeseed/canola oil for frying which I know I won’be able to use for cooking again (I usually cook with grapeseed) so all of will be going down the drain. After reading the thread, I thought maybe I can make it into soap, not for washing, but just so it can go into a landfill rather than the sewers. After all, soaps are biodegradable. Since I’m settled on that, I decided to add something else as well-a carton of expired milk from my fridge. I bought it to make alfredo sauce but then I got sick and forgot about it so it’s been sitting there for two months now. I felt a bit bad to just pour it down the drain-not because of food wasting but it will take a whole lot more water to clean these milk. I knew that you can’t drink spoiled milk because of the bacteria, but what if I add lye? I don’t think many bacteria can survive lye. So if I use frozen spoiled milk as my liquid, add the fryer oil and lye, I can make two trash that may potentially cause water pollution into a biodegradable solid mass that can decompose safely in the landfill. I can even used the milk carton as a mold so I don’t need to wash my silicone mold! What are you guys’ thoughts on this? I will freeze the milk tonight and try the idea after spring-roll-frying is done anyways and update later.