Strong Acid is a refined crafting component in Subnautica 2 used for fiber mesh, power cells, advanced batteries, and several mid-game vehicle parts. Unlike Mild Acid, it cannot be made in the basic Fabricator inside your Lifepod. You need a Processor placed in a powered base before any recipe will work.
Quick answer: Build a powered Processor, then load it with 2x Necrolei Cyst to produce 1x Strong Acid. If you have no cysts, use the alternate recipe of 1x Sulfur and 1x Gold instead.
Requirements before crafting Strong Acid
The Processor blueprint is scanned at the Old Habitat colony ruins, roughly 370 meters north of the Lifepod, in the same area where you scan the Sonic Resonator and Scanner Station. Once scanned, you can build it on a foundation or inside a habitat module.
The Processor itself costs titanium, copper wire, and mild acid, all available from the Fabricator. It must be connected to a power source, either solar panels, a bioreactor, or thermal power, before it will accept inputs.
Strong Acid recipes in the Processor
Two recipes produce Strong Acid. The primary recipe is cheaper and faster early on. The alternate recipe is useful when you set up bases far from the jelly forest or run out of Necrolei Cysts.
| Recipe | Inputs | Output |
|---|---|---|
| Primary | 2x Necrolei Cyst | 1x Strong Acid |
| Alternate | 1x Sulfur + 1x Gold | 1x Strong Acid |
Where to find Necrolei Cysts
Necrolei Cysts grow as flower-like tops on plants in the jelly forest near the Old Habitat, north of the Lifepod. They sit close enough to the starting area that you can reach them with the default oxygen supply, and you can pinpoint them through a Scanner Station after the resource is known to you.
Use the Survival Multitool to harvest each cyst. The plants regrow over time, and harvested cysts can be replanted in an Exterior Growbed or Interior Growbed if you want a sustainable supply at a remote base. The jelly forest is the only natural spawn area for them in the current Early Access build, so farming becomes important if you set up away from this biome.
Alternate recipe: Sulfur and Gold
The alternate path uses one Sulfur and one Gold per bottle. Both spawn in thermal and volcanic areas. The closest reliable Sulfur source early on is the rock pillar about 200 meters southeast of the Lifepod, near the Coral Crabs, with four large deposits that require the Sonic Resonator and several smaller hand-harvestable nodes. Gold appears in the same volcanic zones and in deeper biomes such as the Jellyshroom area.
This recipe is more expensive in practice because Gold has competing demands for advanced wiring kits, entangled power cells, and other late-game components. Use it only when Necrolei Cysts are not practical.
Producing your first Strong Acid
Step 1: Travel north from the Lifepod to the jelly forest near the Old Habitat and harvest at least four Necrolei Cysts with the Survival Multitool. Stay clear of the deeper ravines until you have an upgraded air tank.
Step 2: Return to your base and confirm the Processor has power. If it shows no inputs in the menu, check the connected power source or place the Processor on a powered foundation.
Step 3: Open the Processor, select the Strong Acid recipe, and load two Necrolei Cysts. The machine produces one bottle within a few seconds. Repeat with the remaining cysts to stockpile a second bottle.
What Strong Acid is used for
Strong Acid is a gating ingredient for several mid-game blueprints. Planning your harvests around these recipes prevents repeat trips to the jelly forest.
| Item | Strong Acid needed | Notes |
|---|---|---|
| Fiber Mesh | 1 | Combined with 2x Fiber; required for the Rebreather |
| Power Cell | 1 | Plus 2x Basic Battery and 1x Salt; used in the Tadpole |
| Advanced Battery | 1 | Plus 1x Conduit Crystal and 1x Silver Ingot |
| Entangled Power Cell | 1 | Plus Conduit Crystal, Gold Ingot, and Troilite |
| Dedicated Core | 1 | Plus Advanced Wiring Kit and 2x Quartz |
| Scout Ray Chassis | 1 | Plus 2x Plasteel Ingot, Advanced Wiring Kit, Dedicated Core |
How to confirm the craft worked
A successful craft places a Strong Acid bottle in the Processor's output slot. The item icon is a small flask with a yellow-green liquid. If nothing appears, the most common causes are the Processor having no power, the wrong recipe being selected, or only one Necrolei Cyst loaded instead of two. The Processor consumes inputs only when the full recipe quantity is present.
Once you have a steady supply, Strong Acid stops being a bottleneck and the Rebreather, Tadpole, and later electronics fall into place quickly. Replanting Necrolei Cysts at your main base is the single biggest time-saver if you plan to push deeper biomes.