The Active Hydrogen Plate doesnt reset its freshness after crafting. This makes Science packs very expensive without the aquilo tech to make the plates more efficiently. Pentapod eggs reset freshness on craft beginning, if that makes a difference.
Here is the list of Mods I play with:
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: base version 2.0.77
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: show-missing-bottles-for-current-research version 2.0.2
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: VehicleSnap version 2.0.3
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: Automatic_Train_Painter version 2.0.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: AutoSwitchTechs version 1.8.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: big-brother version 2.0.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: Bottleneck version 0.12.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: bplib version 2.0.0
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: calculator-ui version 2.0.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: CaramelldansenLabs version 2.0.0
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: DiscoScience version 2.0.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: elevated-rails version 2.0.77
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: FilterHelper version 0.2.24
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: flib version 0.16.5
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: inventory-repair version 20.0.3
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: item-request-proxy-events version 0.1.2
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: nuke-cliffs version 20.0.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: Pi-C_lib version 2.0.4
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: quality version 2.0.77
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: tooltip-lib version 0.1.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: train-trails version 1.1.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: TrupenRocks version 1.0.3
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: CharacterModHelper version 2.0.7
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: Milestones version 1.4.7
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: RateCalculator version 3.3.8
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: space-age version 2.0.77
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: behemoth-enemies version 0.0.8
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: BuilderBotStart version 0.4.3
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: corrundum version 1.0.44
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: FactorySearch version 1.14.3
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: MechanicusMiniMAX version 0.1.8
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: PlanetsLibTiers version 1.2.0
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: RocketCargoInsertion version 1.1.1
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: sharper_planets version 1.0.2
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: PlanetsLib version 1.18.0
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: bellicos-and-aegis version 0.2.9
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: Better_Starmap_Background version 2.3.0
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: Redrawn-Space-Connections version 2.4.2
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: rigor-module version 0.7.0
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: visible-planets version 1.7.2
2648.838 Script for name, version in pairs(script.active_mods) do log(name .. " version " .. version) end:1: planet-crucible version 0.5.12

Which recipe is this for: creating activated plates from stable plates, or the science pack? New activated plates from stable plates should always come out 100% fresh, but the "looping" active plates for science packs (and other recipes) are not; they use the standard logic for freshness. The recipe tooltips are a bit confusing because they all say that the plates are always fresh, but this is fixed with Factorio 2.1.

The recipes that loop activated plates never consume the plates, so spoiling is the only thing that can consume them. If you're bottlenecked on active plates, see if you can get more crafts out of each one during its one minute.