what are the recipe's to make this potion

For magical crafting, the Dungeon Master's Guide says to treat a formula as a magic item one step rarer than the item it makes. A Potion of Speed formula would be a legendary magic item, so it would be extremely hard to come by.

This spell cast on you without the possibility of losing concentration is VERY powerful. 
Newbie DM's beware! :) 

Also, FYI, the extra action from Haste "... can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action." So, extra spell casting is precluded.

Haste is especially useful for Rogue Archers using sneak attack.

Quote from JimGettman >>

Haste is especially useful for Rogue Archers using sneak attack.

Keep in mind that sneak attack damage can only occur once per turn regardless. Though it does make sneak attack alot more consistent.

Haste is potent, I play an Arcane Archer, 11 fighter levels for 3 attacks per action and action surge, 3 rogue for assassinate, and I'm aiming for wizard levels now for haste. Once I can cast haste on myself, that will be (potentially) a surprise attack, auto crit and sneak attack, 3 attacks all with sharpshooter, haste action, 3 more attacks, and action surge, 3 more attacks, using lightning arrows and my oathbow, not even including if I nat 20 crit, is a substantial amount of damage.

Just remember that the hasted action is only one weapon attack. It's not a full attack action (3 attacks in your case). 

for rogue use your haste granted action to attack on your turn, and your normally granted action becomes a prepared action to attack on  later turn so both attacks get sneak dice.

Currently obsessed with the idea of playing an Alchemist Artificer that takes like 50 potions before entering combat. Even funnier if the DM uses the optional rules for potion mixing in the dmg

Under a violet moon bring a caldron of freshly collected geyser water to boil.
Stir the water with exactly three fresh porcupine quills, stirring first clockwise for three strokes then once counterclockwise. 
When the moon is at it's peak, (not to be confused with midnight) add the rust from the gears of a broken grandfather clock. Then reduce the mixture until it is the constancy of syrup stirring constantly as previously instructed. 
Bottle the syrup immediately and for maximum potency consume within 3 weeks.
Potions older than 10 years should be deemed unstable and properly disposed of.

Next time your players ask to brew a potion, give them a long list of ingredients and send them on a quest for each of those ingredients. It makes for a great aside while you piece together the next part of your campaign. 

1

Quote from ProGun >>

for rogue use your haste granted action to attack on your turn, and your normally granted action becomes a prepared action to attack on  later turn so both attacks get sneak dice.

 This is incorrect. You only get sneak attack once on your turn. 

"Once per turn, you can deal an extra 1d6 damage to one creature you hit with an attack if you have advantage on the attack roll."

A hasted extra attack is still on your turn. 

When you hold an action, it's not your turn, so you dont get sneak attack damage. 

You use the hasted action immediately. You use it as your “normal” sneak attack. It is a restricted action that can only do listed things and prepared action is not one of them. Use your normal action to prepare to attack on the following turn. Now both actions are eligible for sneak bonus. If you get an opportunity attack you’ll have a third eligible attack. 

Quote from ProGun >>

You use the hasted action immediately. You use it as your “normal” sneak attack. It is a restricted action that can only do listed things and prepared action is not one of them. Use your normal action to prepare to attack on the following turn. Now both actions are eligible for sneak bonus. If you get an opportunity attack you’ll have a third eligible attack. 

 None of those actions are on your turn. They don't count. 

You literally quoted the ability "Once per turn..." it doesn't specify once on YOUR turn, just once per turn. You can get sneak attack on opportunity attacks or any attack you might make as a reaction, such as a readied action or a battlemaster's Commander's Strike maneuver.

So if I drink this and cast haste I’d that +4 AC?

Quote from gillpatrickjake22 >>

So if I drink this and cast haste I’d that +4 AC?

 No, since it gives the effect of haste, it would not stack based on the "similar named effects can't stack" rule. No different than how it also wouldn't work to have 2 different casters try and haste you at the same time.

That's not how it works. The hasted action is not a "full" action, it has rules text that reads "...can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action." - so you wouldn't get 3 attacks from your hasted action, only 1. And if you were a caster you wouldn't be able to cast a spell.

Methamphetamine

Has anyone gotten any confirmation or clarity that if you take this potion that you get the benefits immediately? I know house rules and such can change from DM to DM and table to table, but is it intended to drink this and be able to use the attack option benefit that it specifies in the Haste spell?