Compost Thermometer (50cm Long)

What is the Compost Thermometer and what is it used for?

It’s a stainless steel dial thermometer with a 50cm probe, made for measuring the internal temperature of compost piles. It reads from 10°C to 76°C, helping you monitor microbial activity, check when to turn the pile, and assess compost progress. Also useful for warm soil checks before planting.

How do I use the Compost Thermometer correctly?

Insert the probe deep into the centre of your compost heap (the hot core), wait 1–2 minutes for the needle to stabilise, then read. For accuracy, check 2–3 different spots. Remove after use to prolong its life, and avoid forcing it through dense material.

What do different compost temperatures mean?

Below 30–40°C often means slow activity or imbalance. 40–55°C is a healthy composting zone. 55–65°C is hot composting—great for fast breakdown. Above 65–70°C can stall microbes. Temperature drops often signal it’s time to turn or fuel the pile.

Why isn’t my compost pile heating up?

Common causes include piles that are too small, too dry, not enough greens (nitrogen), or lack of turning. Cold weather also cools outer layers quickly. Check moisture (aim for “damp sponge”), and consider bulking up the pile for better insulation.

Can compost get too hot?

Yes. If it exceeds 65–70°C, beneficial microbes can die off and decomposition can slow. Turn the pile to release heat, add water if dry, or mix in more browns to rebalance.

Can I use the Compost Thermometer for soil or other systems?

Yes—it’s useful for checking raised bed temps, soil warmth before sowing, or monitoring worm farms (which prefer cooler temps). It’s not ideal for bokashi, as that’s fermentation-based and doesn’t generate much heat.

How often should I check compost temperature?

During active hot composting, every 1–2 days is ideal. For slower piles, a few times per week is fine. Consistent checking helps you spot when to turn, water, or adjust your mix.

When is compost “done” according to the thermometer?

Finished compost typically returns to ambient temperature and doesn’t reheat after turning. Check smell (earthy), texture (crumbly), and absence of visible scraps to confirm maturity.

Does the Compost Thermometer help with weed seeds and pathogens?

Yes. Sustained temps in the 55–65°C range help reduce weed seed viability and kill many pathogens. Turning and maintaining moisture levels also play a key role.

Is the Compost Thermometer waterproof or fog-resistant?

The dial is sealed to resist fogging and moisture ingress, but it’s not fully waterproof. Avoid submerging it and store it dry to prolong its lifespan.

How do I clean and maintain the Compost Thermometer?

Wipe the probe after use and dry before storing. You can disinfect it with a mild wipe if using between piles. Don’t leave it exposed to long-term rain or soak it in water.

Does the Compost Thermometer need calibration?

It comes pre-calibrated and doesn’t usually require adjustment. For peace of mind, you can compare it with another thermometer in room temperature or warm water.

Is the Compost Thermometer beginner-friendly?

Yes—just insert, read, and adjust your pile based on what you see. Avoid the common mistake of reading near the edge; always check the centre core for true activity.