Definitely less water! lol - I thought it may have been ok with the jar because I freeze 2 litter bottles of water all the time, 1 in 5 crack but for the most part they are fine for a long time, so I figured it might work, but then I just realized plastic can expand and glass doesn't, so there is where the snafu lies lmao. It seems it expanded quite a bit so I think using less water might not work too well since it would need about the same distance beneath the lid as it came out of the lid, so like 2.5", which would be a pretty big gap for the material to be exposed :/ back to the drawing board lol