The water bath fermantation trick

[tegeberg]

Hi guys (sorry for misspelling the headline

I currently have my second batch, a Belgian wheat in my fermenter, and since it is 25-28 Celsius outside in Montreal these days I decided to try and do some temperature control with a water bath.

I have place my classic plastic bucket fermenter in a large tub filled with water to approx. the level of the beer in the fermenter.

My yeast (Safbrew t-58) says it should ferment well up to around 25 Celcius. But...

1. Am I right in assuming one would generally say the beer would be better if fermenting at a bit of a lower temperature, even if for a Belgian where some esters are desired?

2. I seem to be able to keep the water at a constant of around 20 Celcius, a little less when I add ice to it and it grows some degrees warmer when I am away for work in the afternoon. Will this actually significantly cool the plastic fermenter, or am I barking up the wrong tree here? Should I add even more ice and try to cool it further down?

 

[TopherM21]

Not familiar with that particular strain, but many Belgian yeasts are pretty tolerant in terms of temp.
You should check the manufacturers info for its precise tolerance, but a gradual temp increase in primary should help you brew to style.

 

[Shawn Hargreaves]

Rather than submersing the entire carboy up to the level of the beer, put just six inches or so of water in the outer container, then dress the carboy in an old tshirt which trails in the water.

The former way can only cool to the level of the water bath, which isn't much unless you continually add ice. The latter way, water will wick up into the cloth and evaporate, providing continual cooling.

 

[blakrblak]

I've had success with putting a carboy (or bucket in your case) in a rubbermaid plastic container filled with water. I wrapped everything with two sleeping bags to provide some insulation. By adding 4 L of ice in the morning and 4 L of ice in the evening I kept my system about 10 degC below ambient temperature with little temperature variability throughout the day. This worked great for me as a cheap low tech way to cool down your beer. It may cool the beer down too much for your purposes, but I think if you experimented with insulating your beer and by varying the quantity of ice you use, you could further stabilize your temperatures to the range you need.

But to attempt to answer your questions:
1. I would also check the manufacturers website, but probably temps around 20 and 22 degC would be fine.
2. Yes I think if your water bath covers most of your bucket, then your brew should be about the same temp as the water bath, and will be subject to the same temperature fluctuations.

 

[tegeberg]

Thanks a lot guys, will see how it turns out! For the next batch I will try the t-shirt method for sure.

 

[SailorTodd]

Rather than submersing the entire carboy up to the level of the beer, put just six inches or so of water in the outer container, then dress the carboy in an old tshirt which trails in the water.

The former way can only cool to the level of the water bath, which isn't much unless you continually add ice. The latter way, water will wick up into the cloth and evaporate, providing continual cooling.

I will second the suggestion for this technique, based on observing it at work twice now. Forgive me for speaking in Fahrenheit rather than Celsius (too lazy to do the conversions this morning), but I had a beer that was fermenting about 78F within 12 hrs of pitching yeast, while the ambient temp was 73, way higher than it should have been, so I found a dish that could hold a shallow pool of water, and fit the fermenter's base. I draped a t-shirt over it, and found a small fan to blow continuously on the fermenter. By the next morning, the temp was down to 68F with the ambient temp being 72F. Another day later, it was 66F, which I think was an indication that the fermentation had slowed somewhat. My current batch is also fermenting using this method, and it keeps it a good 3 to 5 F lower than ambient temps when a fermentation normally drives the beer's temperature above the ambient.

As I mentioned I used a fan, which helps get more air flow over the t-shirt, increasing evaporation to improve cooling. Without it, the cooling effect won't be quite as significant. Also, the effect is diminished in a region with higher humidity.

 

[geezerpk]

I use a large piece of muslin (non-terrorist) that wraps the fermenting bucket and drapes down into 6-7 inches of water in a plastic container. I have a small fan aimed at the front of the Rube Goldberg setup, the fan increase evaporationa and cooling, but not so muc that it gets ahead of the wicking action of the cloth. It does a decent job of keeping ambient temperatures around 72º degrees in a 77º room. Not great, but pretty decent for the summer months and most ales.

 

[TopherM21]

Again, many of these Belgian styles will will start with a lower temp and gradually raise it. I'm not saying you're going to want to take a wit as high as, say a saison, but if you want to keep it to style, you should let the yeasties have some fun!