Made it so that the recipe requires some fluid ingredients - mostly to prevent it from being hand-craftable, but also I felt that washing the spoilage with acid and water fits into the concept.

Also restricted the recipe to be craftable on Gleba only.

Sorry if this screws with any existing builds. If you want to revert these changes, I have no objection if you go fiddle with the data.lua file. Here are the relevant lines:

Recipe inputs:
petrificationRecipe.ingredients = {
{type = "item", name = "spoilage", amount = 50},
{type = "fluid", name = "sulfuric-acid", amount = 20},
{type = "fluid", name = "water", amount = 20}
}
(To remove liquid ingredients, remove the two lines that mention sulfuric acid and water, and then remove the comma at the end of the line that mentions spoilage.)

Here are the lines restricting the recipe to the surface of Gleba altogether:
petrificationRecipe.surface_conditions = {
{
property = "pressure",
min = 2000,
max = 2000
}
(If you want to revert this, just remove this whole section altogether.)