How to Set Up a Fermenter Temperature Control Kit (Water or Glycol)
What’s in our fermenter temperature control kit, which version you need, and how to plumb and set it up on a jacketed Unitank with tap water or a glycol chiller, step by step.
In this post
The short answer: our fermenter temperature control kit turns a jacketed Unitank into an automatic, temperature-controlled fermenter. A temperature controller reads the beer through a thermowell and switches cooling on and off: either a solenoid valve on tap water, or the glycol pump on a glycol chiller. You set the temperature once and the kit holds it.
What’s in the kit
| Water kit | Glycol kit | |
|---|---|---|
| Temperature controller | Yes | Yes |
| 1.5" tri-clamp thermowell | Yes | Yes |
| Valves | 120V solenoid valve + full-port ball valve | 2 full-port ball valves, or one ball valve + a 120V solenoid valve |
| Lines and fittings | Quick-disconnect water connection kit, 2 quick-disconnect adapters, 4 tri-clamps with gaskets | 3/8" glycol line set, 2 tri-clamp adapters for the chiller, 6 tri-clamps with gaskets |
| Cools with | Tap water | A glycol chiller |
The jacket is part of the fermenter, not the kit. The kit fits Unitank fermenters and other jacketed fermenters with tri-clamp jacket ports.
Which version do you need?
| Your setup | Choose |
|---|---|
| Cooling with tap water | Water kit |
| Glycol chiller, one pump per fermenter, chiller sitting above the tank | Glycol kit with 2 ball valves. The controller switches that tank’s pump. |
| Glycol chiller, one pump feeding several fermenters | Glycol kit with a solenoid valve on each tank |
| Glycol chiller sitting below the fermenter | Glycol kit with a solenoid valve, so glycol can’t siphon back through the jacket when the pump stops |
Tap water can only cool the beer to a few degrees above your tap water temperature, which is fine for ales in most of the year. For lagers, cold crashing and warm summers, you need glycol.
How to set it up
- Install the thermowell in a 1.5" tri-clamp port on the fermenter, so it sits in the beer, and slide the controller’s probe all the way in.
- Fit the ball valve to the jacket outlet. It lets you disconnect without spilling coolant. Leave it fully open whenever coolant is flowing: never restrict the jacket outlet.
-
Connect the supply to the jacket inlet.
- Water kit: tap water, then the solenoid valve, then the jacket inlet. Run the outlet to a drain.
- Glycol, pump per tank: the chiller’s pump outlet to the jacket inlet (through the second ball valve), and the jacket outlet back to the chiller reservoir.
- Glycol with a solenoid: the solenoid goes on the jacket inlet in place of the second ball valve; the pump runs and the solenoid opens when the tank calls for cooling.
- Plug in the cooling device. The solenoid valve, or the tank’s glycol pump, plugs into the controller’s cooling outlet. The controller needs a 120V outlet.
- Set the controller to cooling, with your target temperature and a small differential, about 0.5 to 1°F (0.3 to 0.5°C).
- Test it with water before your first batch: fill the fermenter, set a temperature below the water temperature and check that cooling switches on, flows and stops.
Watch the setup in our temperature control video.
Typical settings
| Stage | Fermenter setpoint | Cooling |
|---|---|---|
| Ale fermentation | 64–68°F (18–20°C) | Water or glycol |
| Lager fermentation | 48–52°F (9–11°C) | Glycol |
| Diacetyl rest | 60–65°F (16–18°C) | Water or glycol |
| Cold crash | 32–38°F (0–3°C) | Glycol |
| Lagering | 32–34°F (0–1°C) | Glycol, with the chiller set around 28°F (−2°C) |
More detail in our guides to lagering, the diacetyl rest and cold crashing.
Troubleshooting
| Problem | Check |
|---|---|
| Controller calls for cooling but the beer doesn’t cool | Both valves open; the pump or solenoid plugged into the cooling outlet; tap water or glycol cold enough |
| Temperature swings past the setpoint | Probe fully inside the thermowell; differential no more than about 1°F; glycol not far colder than it needs to be |
| Won’t get cold enough on tap water | Tap water is too warm for that setpoint. You need a glycol chiller. |
| Dripping condensation | Insulate the glycol lines and fittings |
| Glycol level changes when the pump stops | The chiller is below the tank; fit the solenoid version |
Frequently asked questions
Do I need a solenoid valve?
For tap water, yes: it’s included in the water kit. For glycol, only if one pump feeds several fermenters or the chiller sits below the tank. With one pump per tank and the chiller above it, the controller switches the pump and two ball valves are all you need.
Can I cold crash with tap water?
Only down to a few degrees above your tap water temperature. For a proper cold crash or lager, you need glycol.
What size glycol chiller do I need?
It depends on how many fermenters, how big, and how cold. Use the sizing calculator on our glycol chillers page.
Does the kit heat as well as cool?
The kit is set up for cooling. Fermentation makes its own heat, so most setups only ever need to cool; in a cold room, keep the fermenter somewhere warmer.