A good fermentation is critical in brewing. Temperature control is a huge part of that. When I got my conical fermenter I needed to figure out a new temperature control method. What I had for my plastic carboys is not large enough to accommodate the conical. So far I have my heating method figured out. Until now I did not need a chilling method. The ambient temperatures over winter were only required heating.
The last couple weeks have accelerated my need for a chilling solution. The outside temperatures have hit the mid 80s earlier than normal and that caused the fermenter in the garage to reach as high as 72 degrees with 5 gallons of beer inside (at least the times I was able to check it). Thankfully the beer still in the conical was just resting on some coffee beans. No harm done.
If I could set up the perfect chilling system, I would have a small glycol chiller in my garage. It would be efficient, I wouldn’t have to change ice bottles, or move the conical in and out of a chamber. Plus it would just be really cool. However, I just spent my money on a conical and a glycol unit is not cheap so that’s not going to happen.
So where does that leave me? The way I see it there are 4 paths forward:
- DIY glycol chiller
- Fermentation Chamber
- Cooler and a pump to circulate chilled water
- Only brew in the winter
Let’s look at these from worst to the winner. Clearly I’m not going to only brew in the winter. That was a dumb idea. Next.
The fermentation chamber is what I had before I got the conical. It worked really well and the reason I’m not using it now is the conical doesn’t fit. I would need to build a new chamber or buy an upright freezer/fridge to do the job. There are logistical issues to this as well. The conical with 10 gallons of beer is heavy and the only spot to put a chamber is on the opposite side of my garage. So it would require a lot of moving the conical around or pumping long distance. The logistics plus the fact that I would be buying a lot of items that could not transfer to a glycol solution later on takes this option off the table.
The DIY glycol option seems like the logical move from an actual glycol chiller. It would involve partially disassembling an air conditioner to chill glycol in a cooler. The glycol would then be pumped through the coil inside the conical. I strongly considered this option, but if the ultimate goal of the chiller is to get to the glycol chiller than I need to save money. The air conditioner is an added expense that would not translate to the glycol solution and would not be reusable after being torn apart for this use.
That leaves the cooler and chilled water option. This is essentially the DIY glycol solution but sub ice packs for the air conditioner and water for the glycol. The big point of this solution is its cheap and can be repurposed. I got all of the pieces for this for about $40. I can reuse the pump and tubing with the glycol solution and I can use the cooler for its intended purpose when I’m done with it. That lets me work towards the glycol chiller with minimal waste. The big downside of this solution is the large increase in labor. I’ll have to keep swapping ice packs to keep the water cold.
- Drill 1/2″ holes in the cooler. Drill pilot holes from the inside of the cooler. I used the grooves in the lid to align the holes with a thin portion of the lid.
- Cut tubing to length
- Attach return hose to the bottom barb of the chilling coil and secure with clamp.
- Attach hose to the pump and secure with clamp.
- Feed hose through cooler and attach to the top barb of the chilling coil. Secure with clamp.
- Drink a beer
Chilling the Conical
The assembly was easy and the use is even easier. Just fill with cold water and ice packs, plug it in to a temperature controller and watch the conical stay cool. Ice packs will need to be swapped out as the chilling water warms. The power cord for the pump is small enough that it can close in the lid without additional modification.
Unfortunately I have not been able to test the cooling efficiency of this setup yet. I confirmed that the pump is strong enough to move the water through the coil. The pump is running in the above picture of the inside of the cooler. It is providing a decent flow. The question now is how fast it can chill and how often the ice packs need to be swapped out. A move might need to be made to a bigger cooler for a larger thermal mass of cooling water.
I’ll have an update on how this works. I have a batch ready to go for this weekend, but the heat has subsided so I may not be able to test out the chilling system too well. The heat will return and then I’ll be able to really put it through its paces.
UPDATE: Although the ambient temperature dropped significantly, I was able to test the chilling setup when my hop screen clogged and I was forced to pour the last 2 gallons hot into the conical. After the wort temperature stabilized at 80 degrees, I filled the cooler with water and a couple ice packs and hooked it up to the temperature controller. It dropped the conical by 4 degrees in about 30 minutes. It was getting late and I needed some rest so I called it a night.
In the morning the wort was still at 72 degrees. I dropped a couple new ice packs in and it took the temp down the rest of the way pretty quickly (I forgot to time it this time). I still need to figure out how the system does managing the temperature. I hopefully won’t need to use it to drop the temperature in this fashion very often.