What would you do as a dm

[kiralon]

If a group of players led a water elemental into a flour mill, dumped a heap of flour on it and cast wall of fire on it.

Have water elemental bread?
Give them a more annoyed water elemental?

Can other substances mix with a water elemental?

[Library Ogre]

The water elemental would take damage. If it took a lot of damage, it would die, leaving behind some very sad bread. If it didn't take enough damage to kill it, I'd say it could flush the flour out.

But, keep in mind how much we're talking about. In making bread, you're talking 1 cup of water per 3 cups of flour. A human-sized water elemental is about 16 gallons (about 128 pounds), so you're talking about 240 pounds of flour (roughly 5 pounds of flour in a gallon of flour, and you need 16*3 gallons, so 16*15 pounds).

But that's human sized. A minor water elemental is 11 feet tall and weighs a literal ton, so you'd need about about three tons of flour to breadify a minor water elemental. Want to turn a major elemental into a whitebread man? You're gonna need 30 TONS of flour at the lower end.

[kiralon]

Hmm, damage to kill it rather than slow it is a pretty good idea, i was just thinking of the slowing aspect and sort of turning into a mud/flour mound, but you are right, having a silo load of flour land on you wouldn't be comfortable for anybody. My minor water elementals are usually around 5ft but i would have to check first ed to know what they really should be, but my mind tells me not too large, but i could easily be wrong.

[The Dark Elf]

The Elemental can manipulate its shape to rinse the flour off. Plus the water elemental is a being so does the flour actually mix with the water or just lay on top of it??

A lot depends on the amount of flour (I expect its not a lot)

Also the heat isn't a slow bake so it my not rise (not that I know much at all about bread making).

More questions that answers, sorry - but food (bread?) for thought.

Also - the first thing I would do as a DM is be playing D&D

[Veknironth]

Well, I guess it depends on how you envision elementals being formed. Are they the element inside of some magic shell? If that's the case, then the flour just covers its skin. Good to keep it from turning invisible, but it wouldn't mix with the water. If it's the element being held together from the inside, then I think the elemental can move its constituent parts around to let the flour pass.

The heat, however, would damage the elemental.

-Vek
"DE, playing D&D? Say it ain't so!"

[kiralon]

The Elemental can manipulate its shape to rinse the flour off. Plus the water elemental is a being so does the flour actually mix with the water or just lay on top of it??

A lot depends on the amount of flour (I expect its not a lot)

Also the heat isn't a slow bake so it my not rise (not that I know much at all about bread making).

More questions that answers, sorry - but food (bread?) for thought.

Also - the first thing I would do as a DM is be playing D&D

The mixing bit was what i was wondering, and i always assume the elemental uses its element to form a body, so if there is no water, there is no water elemental.
It was a very large hopper full of flour where they fill bags of flour and all at once, so it was a decent amount.
I wasn't really thinking of rising but something more like a flatbread, burnt on the outside, watery on the inside.

I still have issues with d&d but i stole everything i liked out of it and put it in my homebrew palladium, so when i play, i play a bit of d&d at the same time. I must say it was mostly first and second ed stuff that i stole, but i have also used pathfinder and later version of d&d stuff, for example, a magic sword that gives you advantage with parrying is a great magic sword. Not to mention the magic rolls into palladium pretty cleanly too.

[kiralon]

Well, I guess it depends on how you envision elementals being formed. Are they the element inside of some magic shell? If that's the case, then the flour just covers its skin. Good to keep it from turning invisible, but it wouldn't mix with the water. If it's the element being held together from the inside, then I think the elemental can move its constituent parts around to let the flour pass.

The heat, however, would damage the elemental.

-Vek
"DE, playing D&D? Say it ain't so!"

But if it was suddenly covered in 10 times its volume in flour, as in a large hopper full of flour being dumped on it.
The fire certainly would hurt it but wouldn't kill it as it would move out of it, the flour was to more hinder it and keep it in place..

Do water elementals "bleed" water when struck?

[ShadowLogan]

If a group of players led a water elemental into a flour mill, dumped a heap of flour on it and cast wall of fire on it.

Have water elemental bread?
Give them a more annoyed water elemental?

I do not think you will end up with Elemental Bread, but rather a very annoyed Water Elemental.

Why? Well...
1. Dropping the Flour on it will result in the material to "slosh right through the thing" (D&G's entry on Minor and Major Water Elemental pg65/67) since that is what will happen with normal weapons. And as the flour is "normal" it will likely just pass through as if it was a weapon, though even if you don't do that... Further the "Impervious to Kinetic & Stabbing Attacks" Ability doesn't cover dumping flour on one, but "having a great weight drop or slam into it [...], but temporarily spalter the elemental.", so it is likely the Elemental doesn't even absorb or get covered in the stuff, it just gets splattered (it will take 1d4 melee rounds to reform).

2. Technically speaking, bread requires water, flour, salt and yeast (you can sub. out the yeast). But then you have mixing of the ingredients (and no just dumping the flour onto the water elemental to be absorbed doesn't cut it). Casting of the Wall of Fire won't constitute baking conditions IMHO and then you have to consider baking time (this means even if you allow the WoF to bake the mixture, it will require either multiple castings or HIGH Level to get the necessary duration) and temperature (which is absent from pretty much every fire spell). And given the Water Elemental's heat resistance it could complicate baking times.

3. Nor is the Elemental likely to just stay put and allow themselves to be er... cooked (even ignoring points 1 & 2), and during the cooking time should be trying to get away from the fire. They do have Level 1-4 Water Elemental Spells available (if Minor, a Major Elemental is even more powerful), as they could just cast: Create Water or Circle of Rain in an attempt to put out the fire, or Reist Fire (reduce fire's effect) or even Wall of Ice (block the fire). Or even you know release the current body to go make a new one (or if Major possession of another). They might also use their "Water Jet" Ability (pg65/67 D&G) to attack the fire, or their "Seep through cracks and openings" Ability if they notice something they can slip out via (which probably also means they could purge themself of contaminants).

4. The weight of all the flour might not be an issue in terms of pinning them down, a Minor Elemental has a SN PS of 22 (min, 32 max) and a Major is SN PS of 47 (min, 62 max), and both fall in the x50 PS carry modifier (Lift is x2) so they can LIFT ~1 US ton (2,200lbs) at minimum, which likely means they aren't going to be getting pinned down easily (ignoring they likely are going splat).

Can other substances mix with a water elemental?

Yes, other substances can mix/be mixed in with the water elemental's body. Text in D&G (pg67 for Major, and more general back on pg53) mentions "The creature can be a pillar or wall of flowing water, a lumbering creature of ice, or a bizarre collection of sea creatures molded into a body; the latter seems to be a favorite. It is interesting to note that the sea creatures are covered in a sheet of flowing water." (This per the Major, Minor doesn't have anything like this). So, I would say yes other substances or even creatures can make up its body, especially when you consider that it is impervious to chemicals/drugs/poisons and disease (bacteria and virus causing ones) and how one sees that working.

I don't know if I'd say the result mix of Flour and Water Elemental body results in a dough/mud creature, more of a "lava lamp" type situation with the flour floating around in the body.

Do water elementals "bleed" water when struck?

If the body is a collection of sea creatures, yes (if the creatures are struck). Otherwise No as it is actually an energy being and their "physical body" only mimics the outer shape and not internal workings. That doesn't mean you can't remove water IMHO from the body as an attack, but it would be more like "spit" than "bleed".

[kiralon]

Second ed has a better write up them that's for sure. As i play 1st edish mostly my minor elementals are smaller and less kick ass. They can be big but the minors i have at around 5 ft tall 3ft diameter column of water, but i do use the magical weapons are needed to hurt them, but that was more of a dragover from er other games. Basically a big hopper full (10x10x15 ft) of ground flour dropped on one and looking at second ed it looks like it would have been barely an inconvenience. I was more thinking if the pressure could force it to integrate with the flour but I guess it can't.
I did allow it however as it was a funny thought.
Cheers

[Veknironth]

Well, this does bring up an interesting question. For most minor elementals, they are immune to normal weapons, but take double damage from magic attacks of a different elemental type. I don't know if Kiralon's elementals have the same immunities, but it would seem that in 2nd Ed, no amount of normal flour would damage the elemental. It might trap the elemental if there was no room for it to move, but it wouldn't damage the elemental since it isn't magical. I guess the elemental could slosh through the cracks in the flour particles. Or it could let its body go and then reform it? The air elementals can be dispersed by an explosion (however you do that in PFRPG) and can reform in one attack.

The same question would relate to earth elementals in the rain or a body of water. Those do damage to fire elementals, but apparently do nothing to earth elementals.

-Vek
"Elementals are strange."

[ShadowLogan]

Well, this does bring up an interesting question. For most minor elementals, they are immune to normal weapons, but take double damage from magic attacks of a different elemental type. I don't know if Kiralon's elementals have the same immunities, but it would seem that in 2nd Ed, no amount of normal flour would damage the elemental. It might trap the elemental if there was no room for it to move, but it wouldn't damage the elemental since it isn't magical. I guess the elemental could slosh through the cracks in the flour particles. Or it could let its body go and then reform it? The air elementals can be dispersed by an explosion (however you do that in PFRPG) and can reform in one attack.

The same question would relate to earth elementals in the rain or a body of water. Those do damage to fire elementals, but apparently do nothing to earth elementals.

-Vek
"Elementals are strange."

While I agree the Elemental would not take damage from the flour, it would still physically react to it being dropped on it as outlined in the OP's scenario (at least as defined in 2E)

Invulnerable does not mean immovable as even the description of the Water Elemental's invulnerability allows it to be "moved".