What does Monster Extract do?

I got some Monster Extract from a quest, and also can buy some from the Monster Shop.

What does it do? Does it extend the effect in the food like salt, or does it do something else entirely?

Solution 1:

Monster Extract's main uses are:

Randomly restores or removes Heart Containers

Cooking Ingredient

In terms of being used for cooking, it looks like it has a very high chance of greatly increasing your meal's potency. From this PSA:

I found and tested a way to make maximum potency, 30-minute dishes using Monster Extract. This relies on you being pretty late in the game (consistent access to Monster Extract consistent access to the recipe parts you need), but it's pretty simple!

Basically, to make a 30-minute food item, your recipe should be:

2 Fruits with your intended status

2 Mushrooms with your intended status

Monster Extract

I have not yet found a stealth fruit, but this works with all resists (fire/ice/elec), haste, power up, and defense up (pumpkins are fruits for these intents and purposes).

Feel free to let me know if a recipe you use doesn't work - but I've yet to have it fail!

UPDATE: Because Monster Extract is random (and I'm apparently lucky as hell), this is not guaranteed, but this seems to have a VERY HIGH chance. Just throw a few of this recipe at it and hope for the best.

Solution 2:

Monster Extract is a "filler" ingredient that can be used in both food recipes and elixirs. It randomizes up to three things (if applicable to the recipe):

Hearts recovered: The number of hearts recovered by the recipe may be increased over the base by 3, remain the same, or be set (regardless of the base) to recovering only 1/4 of a heart.
Effect potency: The potency of a recipe (i.e. the strength of the stealth/cold resistance/attack boost/etc.) may be increased or decreased one level, or remain the same.
Duration: Recipes with a timed effect will have their duration set to either 1, 10, or 30 minutes, regardless of the duration imparted by the other ingredients.

Cooking with monster extract will never result in a "critical" success (with an additional bonus), even if cooked during a blood moon.

This answer is based on both my own experimentation as well as the following sources: