I just joined and I am new to the soap making business. So far I have made a couple of small batches. If I wanted to scale up and make a 40lb batch, what size pot would I need to meet and warm the oils?
I totally get being really excited about making soap, but you really need to slow down. First of all, by your own admission, you're only made a couple of small batches and if your Joined date is an indicator, those batches haven't even had time to cure properly to know if your recipe is any good. Speaking as someone who started selling just six months after my first batch of soap...no. My story is that I wasn't planning on selling, but my soap had tested well and an opportunity came up to do a local Craft Fair. I didn't even get halfway through the first day when I realized that I had no business selling soap. I had a good mind you, I still use the same recipe, but you really need a good year to know your recipe. I keep two bars of soap on my desk...both are unscented, both are uncolored, both made from the same recipe...they only difference is that they were made a year apart. And it shows in the texture of the soap...the first soap looks grainy and color is uneven...the second bar looks as smooth a silk and so creamy.
I'm not sure you realize that 40lbs is a lot of soap. Forty pounds of oils/butters, plus water and lye (33%), and fragrance (6%)...works out to be around 60lbs of batter or 190 5oz bars of soap. Even if you're talking about 40lbs total batch weight, that's 128 5oz bars. The largest retail slab molds that I have seen hold around 25lbs (regular) to 32lbs (tall & skinny) and there is a reason for that...you have to move that sucker!
I Master Batch...that means that I pre-make my oils/butters and my Lye Solution (separate containers). I Master Batch 40lbs of oils/butters at a time, but not all at once...partly for weight, partly for safety (hot oils). And I store my MB'd oils/butter in a 5 gal food-safe bucket set on wheels (bought after the first time I tried to move the bucket). The only time I lift that bucket is when I can't use a ladle anymore to scoop with and then I pour into a 1-gal bucket, wash the 5-gal and start over.
Highly, HIGHLY recommend that you first learn how to crawl, then cruise the furniture, then walk. If you try to run right now, it'll be smack dab into a wall.
I probably should mention that 25lb to 32lbs slab molds run about $150 to $175, plus your going to need a slab cutter...that's about $100 (or more).