Fermentation has become a major focus of improvement in my brewing efforts. After all, why waste a batch of beer you spend hours brewing and preparing for only to slack on the cold side of the whole process?
I mentioned this in a previous blog post, but the biggest improvement in my homebrew came from proper pitching temps and temperature-controlled fermentation! Actively fermenting beer can be 10 degrees higher in the fermentation vessel than the ambient temperature of the room. So if your brewhouse is 70°F your beer could be 80°F during active fermentation. Yeast produces more esters and off-flavors at higher temperatures, therefore a cooler fermentation is going to produce greatly improved results. The whole “my basement is about 68°F” school of thought is simply not going to cut it.
It’s amazing to watch the fermenter temp increase from a pitching temp of 68°F to 78°F overnight.
The Cooling System
I recently upgraded from a standard plastic bucket to the stainless Anvil Bucket and Anvil Cooling System as a temp controlled fermenter. It’s worth noting that the Anvil fermenter and the cooling system are sold separately. I’m pleased with the vessel’s functionality as an entry-level stainless fermenter. The cooling system however has been critical in maintaining my fermentation temps down to the degree. I use an Inkbird digital temperature controller to easily ferment in the 64°F-68°F range. The newly supplied thermostat with the system also works just as well.
I would absolutely recommend this fermenter for anyone looking to get started with more control over their fermenting environment.
The cooling system comes with a pump, Anvil temp controller, long stainless cooling coil, a thermowell, and a no. 7 rubber stopper. The coils and thermowell pass through the stopper and extend into the fermenter. The thermowell sits about halfway down the bucket and the coils reach a few inches from the bottom of the vessel.
How Does it Work?
The digital thermometer probe fits into the thermowell and will give you a digital temp reading at the very center of the fermenter. You set your desired fermentation temp on the controller and plug the supplied pump into the controller. If the temperature of the vessel raises even 1 degree (you can change the variance on the Inkbird controller), it will activate the pump and cycle cold water (from a cooler) through the coils, bringing down the temp pretty quickly.
I was really surprised how well this unit could hold a temperature at 66°F throughout an aggressively fermenting NEIPA with loads of dry hops.
You’ll need a cooler full of ice water as the water supply for the cooling system. This is absolutely the most inefficient part of the entire process. The water often returns to room temp every 6-8 hours and renders your cooling efforts useless. You will need to swap out fresh ice or ice packs daily to ensure your water supply remains cold.
Overall this setup is one of the more budget-friendly solutions to control fermentation temps precisely. Sure you can improvise with draping your fermenter with a cold or frozen towel or keep your fermenter in the bathtub but you certainly won’t get this level of control.
Can I Use The Cooling System in A Glass Carboy?
You absolutely can. Just note the supplied stopper is a no. 7 stopper so you will need a carboy with a no 7. mouth. Anvil makes a carboy version of the cooling system as well.
Other Ways to Keep The Water Supply Cold?
I’m thinking my next project will be a DIY glycol chiller as the cooling source. If you have an extra mini fridge with a freezer on hand you could drill holes in it for the tubing to pass through and create a closed-loop glycol system with a glycol reservoir inside. A 50-50 mix of glycol and water has a freezing point of -35°F. The solution won’t freeze in the freezer and will deliver colder liquid through your cooling coil—and most importantly the liquid will STAY cool.
It won’t be ultra-efficient like a true glycol setup but it would be better than nothing. You would still need another means to cold crash.
My vision is to pick up a small mini freezer like this and fill as big of a container as I can with 50-50 glycol and water mix as the cooling source. The other option is to buy a larger fridge and place the fermenter directly in the fridge. It just could be a pricier solution at this point but would be better for cold crashing. I’m not sure the Anvil coil is large enough for getting the beer realistically below 50°F.
Overall, the Anvil system is a really great product and a stellar way to really improve your homebrew without breaking the bank. The fermenter is well made, easy to clean, and can be set up for closed transfers with some inexpensive modifications. I would definitely recommend the stainless Anvil Bucket and Anvil Cooling System if you are looking to move to stainless and step up your fermentation control.