How do guilds deal with consumables, guild alchemists, etc? I can see two main options and I'm sure there are more, and wonder what people actually do.

1. Individuals showing up at a raid are expected to bring all consumables, individually obtained. Method for obtaining is up to the individual.

2. The guild subsidizes and coordinates guild alchemists to have enough high-end consumables (thinking mainly flasks here) such that raid members will get the appropriate kind/number free. (Or perhaps at a discount.)

Obviously #1 is simple and takes little coordination. At most a buff check, or perhaps you only care if someone's not performing up to snuff in the raid.

Option #2 would seem to be quite complicated, keeping track of expenditures, and keeping guild-use mats and personal-use mats separate. But it would ensure that guild alchemists make as many discoveries as possible, and would take advantage of elixir specialists' creating multiples. And it would seem to give a solid role to guildies.

Are there other options? Do people do anything but option #1?

My current guild does method #1, expecting all raid members to have 2 flasks and a reasonable amount of food on them to last 4 hours of attempts on a new boss (although there's nothing new at this point).

Our guild cooks often bring feasts to help alleviate the need for everyone to farm their own food and cut down on overall costs and most members carry extra flasks to lend to like-classes. If we're pushing for an achievement or new boss (come ulduar), being prepared with consumables can be what earns a raid spot over someone else who's equally skilled but negligent on that end.

On my server, I know of at least one guild who provides flasks for their raid members during progression, funded via selling naxx 25 gear.

It don't see how the latter is exclusive with option 1. My guild makes individuals responsible for bringing their own consumables, which most often results in people getting the mats and bringing them to the guild elixir spec alchemists to do.

Another option, which was not an 'official' policy of my previous guild but ended up being the way we did things for a while, was for everyone to bring consumables as they felt appropriate, but have one officer bring a bag full of other consumables that would only be used in cases where it seemed like it would make a difference.
The basic idea is that for things like potions and elixirs, one of two conditions will hold: either you are very likely to beat the content without them, or you are going to run up a huge bill if you try to use them on repeated learning attempts at a boss. So it makes sense to try without them, see if everyone has the strat down (has learned to kill sparks / not to stand in the fire / not cross charges / whatever) - and then, if you're failing some gear check aspect of the fight, break out the guild supplies.
Mind you, this was pre-WoTLK. With flasks as cheap as they are now, it makes more sense to just have individuals provide their own buffs (usually flasks). Guild officers provide food buffs via feasts. It helps that things are generally easy enough that if someone slacks and doesn't buff themselves, there aren't many places where it is likely to matter.

Also, it should be noted that WotLK elixir discoveries aren't discovered by making elixirs or flasks, but by doing Northrend Alchemy Research on a 3 day cooldown. Northrend elemental transmutes are still discovered by doing northrend transmutes, but that generally isn't relevant to raid consumables.

Northrend flasks are learned at a trainer, available to everyone at 435 or higher.

Alchemy - Recipes - World of Warcraft

Edit: Misread your post, you are correct that Elixirs are learned through the Northrend Alchemy Research. Flasks are trivial to learn, unlike the TBC ones.

We're on a fairly low pop server (Fenris) with an even lower concentration of Horde. Our AH is very unstable compared to other servers and subject to large price swings (and out of stock items), especially on raiding nights. For this reason, we made it guild policy to actively collect donations and provide raid flasks for all scheduled events.

We had too many people show up in TBC without flasks because they simply couldn't reliably buy the necessary mats or flasks on raid nights.

This way has worked great. Herbs are so easy to farm...a handful of generous herbalists are keeping our supply up and are still making personal profit selling excess herbs. Non herbalists have made generous gold donations, so we can always buy what we need in case of shortfalls and we typically buy only extra Frost Lotus.

Some people bring their own, but the large majority of our raiders are donating and using the guild supplied flasks. We've probably driven the cost to make Northrend flasks below 20g (after herb donations) each, whereas most posted on our Horde AH are listed around 65-80g.

And everyone is flasked come raid time...which was ultimately our goal.

Are you sure? I am using the Research at every cooldown, but I've definitely still discovered things by making things. Maybe they were just BC recipes I never picked up in Outlands? (Actually, by pure coincidence, I discovered a recipe making the last item that put my skill high enough to pick up the Research skill.)

I'm pretty sure, but not positive. I know you can still get TBC discoveries. I learned Flask of Blinding Light while leveling up from 375 to 450. Most of the WotLK elixirs are 45 to a various rating, so they're easy to recognize.

Have you learned any of these outside of northrend alchemy research? Alchemy - Recipes - World of Warcraft

This should be a requirement of any guild that's serious about raiding. There's really nothing else to say on the topic. Either you put in the work required (which in WotLK is next to nothing) or you don't get to raid.

This thread isn't particularly constructive. The general discussion at hand has been touched on in a number of other threads on raiding -- this doesn't bring anything new to the table, nor is it particularly relevant. Closing.