lots of people have already mentioned the difficulty, but i just wanted to quantify it a bit more. day 1, there's six ingredients, meaning there's 6 * 5 * 4 = 120 combinations. technically some of them are duplicates, e.g. sometimes two of X plus one of Y doesn't depend on the Y, but this isn't a hard and fast rule as i found out. so, the player is basically required to search through 120 possible combinations to find any item they don't know, which is a lot.
for context: it takes me about 3.5 seconds to try a recipe. so, to try all 120 for just the first day would take me about 7 minutes. (of course, some of these can be tried on level 0 so it's not all bad).
similarly, level 2 has 9 items, so the total number of new combos is (9 * 8 * 7 - 120) = 384 which would take me 19 minutes to test all of.
there are a few tweaks that i think would really help:
1. make it so that you can see the ingredients that you just melded. this way, you can write them down in a notepad document or similar with the outcome. i actually really love games that require note-taking like this, but it is trickier when you have to remember exactly what you just put in the pot.
2. make it so that instead of dragging the ingredients, clicking on one will fill the leftmost empty slot. that way, trying recipes is as easy as "click click click," rather than click-and-drag-and-move-your-mouse-back-to-the-right x 3. (i actually immediately resized the window when playing to help minimize my mouse movement).
3. unfortunately, probably reducing the number of ingredients is your best bet. keep in mind that, for example, going from 6->7 ingredients still adds 90 new recipes. one other option would be to make it so that the "two of anything doesn't depend on the third ingredient" rule always holds, which would narrow down the testing space a bit.
also, one more small issue: the "main menu" button and "quit" button seem quite similar on the end screen, and i accidentally quit after first beating level 1.
anyways. i did eventually get through level 2, with enough note-taking. it seems like customers often ask for day-0 combos which is very very helpful. i don't think i figured out a single level 2 combo that any of the customers actually asked for--i remember i could not figure out large condoms, a fleshlight, and several variants of candles.
as i said i do like note taking games and i was having fun writing down some of the wackier combos that i ended up seeing. i also think that memorizing a mental map of item icons -> item names (so that i can look them up in my notepad) ended up being quite fun, as a lot of the items had funny concepts or names.
and, i like the customer drawings. i think the art really is quite fun here, and i can see why you wanted to add a lot of recipes to show off more silly items.