Nutrient paste dispenser

For the meal the dispenser dispenses, see Nutrient paste meal.

The nutrient paste dispenser is an electrical device that converts raw food placed in an adjacent hopper into nutrient paste meals; the machine accepts all food except hay. The meals are produced on demand, when a colonist or prisoner uses the machine. Animals cannot use the machine, but will eat the produced meals if they are fed to them by other means.

It can be constructed with 125 Steel, 3 Components in 2,200 ticks (36.67 secs) once Nutrient Paste has been researched.

Summary

The nutrient paste dispenser acts like a wall, and will seperate rooms. This can be used to refrigerate food on one side of the dispenser, or lock in prisoner rooms. It can't be uninstalled, only deconstructed, at the usual loss of half the material.

Colonists and prisoners will automatically use the dispenser when they are hungry. The paste dispenser must be accessible and be connected to enough power. At least one Hopper is required to input food into, and there must be sufficent raw food inside them. No work bills or tasks can be performed at the machine, and no skills are necessary to use it. In order to produce meals for storage, you must manually manipulate a pawn - see below for details.

Hoppers can be placed anywhere along all 4 sides except the interaction spot (front center), so a maximum of 13 hoppers can be attached. Hoppers act like stockpile zones, so colonists will deliver food as a hauling task. To ensure that your hoppers are full, make sure their settings for Priority are higher than other food storage zones. Hoppers can only hold one type of food at a time, so having multiple is recommended.

Paste dispensers will automatically use food that is closest to spoiling, and multiple types of food can be used at once. All food except hay is usable by the machine, but colonists can only deliver raw food. It is possible to force food on top of a hopper by taking it to a pawn's inventory and then manually dropping it in front of the hopper - this may be considered an exploit. While this will hide the source of most food, be aware that converting human or insect meat to a nutrient paste meal does not mask its origins, and both negative moodlets will be recieved together.

If the front end of the machine is inside a prison cell, then only prisoners will be allowed to use it. This is indicated by the front of the machine turning from green to yellow/orange, similar to how beds change color. Alternatively, colonists with the "Warden" task can deliver nutrient paste from an external machine to prisoners.

When consumed, nutrient paste gives a -4 mood penalty ("Ate awful meal"), which is at least better than eating raw food. Pawns will always prefer a more tasty food, so unless their Food Restriction is specifically assigned to "Paste" (located at the top of a colonist's Health tab), they will only use the dispenser if no better option is available.

Note: There is a minor bug with hopper placement and usage - see Hopper for details before placing/using hoppers for your NPD.

When you build a NPD, the game will notify a hopper is needed
Hopper storage menu to select ingredients
Hopper mouse indicator will turn from red to green for correct placement and colonists will pick NP meals from the dispenser

Analysis

Nutrient paste is the most efficent way to prepare a meal, with 300% food efficency (tripling raw food). Compared to the next best method, simple and fine meals, paste is 66.67% more efficient. This makes nutrient paste useful in a famine, even if you don't plan to use it indefintely. In addition, no cooking is necessary. There's no risk of food poisoning, and it can save a lot of time off a cook's hands - cooking is often a full time job in large colonies. Overall, a nutrient paste dispenser can accelerate the development of a colony, and may be necessary in an extreme biome like ice sheet.

However, nutrient paste meals give a -4 mood debuff, which ends up being -9 net mood compared to fine meals. It is advised to not give nutrient paste to pawns with a trait that gives a negative modifier to mental break threshold, because they can push a pawn over the edge. Because pawns prefer normal meals over nutrient paste, you can set restrictions to prevent normal pawns from consuming all of the good meals and leaving none to the volatile ones.

The mood penalty is negated if the colonist eating it has a precept "Eating Nutrient paste" as "Don't mind" for their Ideoligion.

The paste dispenser also makes it a lot easier to keep animals that need to be fed by the colonists (such as dogs and grazing animals off the growing season). Feeding animals with paste requires occasional micro-management to create meal reserves, since animals cannot trigger the dispenser themselves.

Manually producing meals

Using the paste dispenser is an automatic task that cannot be explicitely triggered. It is still possible to make a pawn produce as many meals as you want, until the machine runs out of raw food to process.

You need at least one pawn to be hungry enough to demand a meal. This will happen at least once per day, per pawn.

Forcing the pawn to create meals exploits the fact that a pawn stops their current action when they are drafted. We also need to keep the colonist away from any food, so they will be forced to keep producing new meals at the paste dispenser.

Method 1: using a special zone restriction (recommended)

The following method uses a 1-tile zone restriction that is placed in the middle of the dispenser. This is the easiest method for producing more than one stack of meals at a time. In detail:

Create a new area that covers exactly 1 tile in the center of the main body of the nutrient paste dispenser (as shown in the screenshot). The exact location of this area matters, in order for the pawn to be able to path to the paste dispenser.
When one of your colonists (it does not matter which one) becomes hungry, and is about to eat a meal, pause the game and restrict the pawn to the area created in step one. You might also have to draft and undraft the colonist so he will stop the current action. The pawn will now be unable to do anything except produce meals at the paste dispenser, due to the zone restriction he is now under. He will even be unable to grab meals that are right on top of him, including the ones he produces from the machine!
Wait for the colonist to walk up to the paste dispenser and draw a meal from the machine. Pause the game again at this point.
To start mass producing meals, simply draft and undraft the pawn as many times as desired. Each cycle will instantly procure another meal from the dispenser, using up some of the resources from the hoppers. The meal is not consumed by the colonist, because drafting him will make him drop the meal on the floor, where it will be out of reach (due to the zone restriction). You can hold down the draft hotkey to rapidly mass produce meals.
When you are finished, simply undraft the pawn a final time and remove the zone restriction from him. Done.

The entire process will require no in-game time, since the game is paused all the way.

Notes:

If you wait a little to long with pausing the game, after the pawn has produced a meal, they will move away from the dispenser and consume the meal (ignoring the zone restriction). This is not a problem: simply draft and undraft the pawn, they will drop the meal on the ground and you can resume again at step 3 above.
Pawns may prefer to eat meals that are already made, and not use the paste dispenser in those situations, depending on several factors that are difficult to control. If you want to protect your bulk-produced meals from colonists, you have to forbid the stacks or exclude the colonists from the area they are stored in. Domesticated animals will not eat from forbidden stacks, so an exclusion zone has to be used to reserve the food for animals.
Many pawns want to eat after getting up in the morning. This makes it easier to watch for hungry pawns if you plan to mass produce some meals.

The pawn is restricted to a 1-by-1 tile wide area which is placed in the middle of the nutrient paste dispenser. The precise location of the zone is important. The pawn will now produce meals indefinitely when drafted and undrafted in front of the dispenser (while there is material on top of the hoppers).
This is the state after all hoppers are depleted. The pawn is now surrounded by stacks of nutrient paste meals. He is still unable to eat any of them, due to the zone restriction (which can now be removed and the pawn undrafted). Note that none of the meal stacks are forbidden, because that is not necessary with this method.

Now you can have as many nutrient paste meals as your heart desires! Enough to take with you on cold journeys! Enough to make an emergency food stockpile! Enough to use as animal fodder!

Method 2: manually forbidding stacks (casual use)

If you do not want to deal with zone restrictions, you proceed as in method 1, but then you have to forbid any new meal stacks that are created, before continuing to cycle the drafting. This method is a little inconvenient if you want to produce more than a single stack of meals, or if you repeat the process regularly (eg. to produce animal food).

The pawn has just grabbed a meal from the dispenser, and wants to eat it. The game is paused at this point. If you draft the pawn now, he will drop the meal on the floor.
This is how it looks like after a couple of stacks have been produced, simply by drafting and undrafting the pawn. The game remains paused all the way. When a new stack appears, it has to be forbidden for the process to continue.
Beyond 3 tiles, you do not even need to forbid stacks any more.