Fluctuating temp while fermenting

[Joey_G]

Hi there,

So I've brewed my first batch of home brew (a boozy porter), and it's currently bucketed and fermenting. So far, everything has gone fairly smoothly. Alas, I'm in L.A., and we're currently battling some beastly temps and I'm a little concerned.

I'm keeping the bucket in my bedroom where I have an air conditioner pumping pretty much 24/7. But sometimes the room gets a little too cold, so I turn it off. I have a thermometer resting on top of the bucket and have seen the temp go up and down over the past 5 days, hovering between low-60s and low-70s.

So: is this going to affect the final product? Is this an issue at all? There's not a whole lot I can do, so I'm hoping this is a minor thing.

Thanks in advance for the info!

 

[JJack887]

All I can say is this: Always wrap a cold, wet towel around the fermentor during initial fermentation. Phenols from high temps are a bitch. And I'm in PA, so this goes double for you.

 

[ChelisHubby]

Hi there,

So I've brewed my first batch of home brew (a boozy porter), and it's currently bucketed and fermenting. So far, everything has gone fairly smoothly. Alas, I'm in L.A., and we're currently battling some beastly temps and I'm a little concerned.

I'm keeping the bucket in my bedroom where I have an air conditioner pumping pretty much 24/7. But sometimes the room gets a little too cold, so I turn it off. I have a thermometer resting on top of the bucket and have seen the temp go up and down over the past 5 days, hovering between low-60s and low-70s.

So: is this going to affect the final product? Is this an issue at all? There's not a whole lot I can do, so I'm hoping this is a minor thing.

Thanks in advance for the info!

I would want to keep the temps in the 60s during the first 5 days as that is where the poor flavors can start. the fluctuation is hard on the yeast but it will be a minor thing compared to 70 + degree fermentation the first few days.

 

[Sadu]

What you need is a swamp cooler. You put the fermentor bucket in a tub of cold water and this keeps the temperature less vulnerable to changes in abbient temperature.

Then you can throw in a frozen ice bottle into the water if things start getting too hot. You can put in a frozen bottle in the morning before you head out to work or whatever and this can keep it stable to get through the day.

The key is to keep it cool (low 60s is best but definitely below 70) for the first few days.

 

[Ogri]

Basically, Joey G, this.

What you need is a swamp cooler. You put the fermentor bucket in a tub of cold water and this keeps the temperature less vulnerable to changes in abbient temperature.

Then you can throw in a frozen ice bottle into the water if things start getting too hot. You can put in a frozen bottle in the morning before you head out to work or whatever and this can keep it stable to get through the day.

The key is to keep it cool (low 60s is best but definitely below 70) for the first few days.

I feel for you, mate. I just did my first brew in two and a half years,,,,,,,,,,got everything sorted and committed to my brew day then a typhoon and exceptionally hot/humid weather front hit me, here in Osaka, so I'm battling temps of 32 degrees centigrade and 90 something% humidity. Even using a swamp cooler with iced water bottles, a towel and ground fan I'm fluctuating between 19 to 23 degrees centigrade over the
last couple of days since pitching. Don't have an air conditioner in my fermentation room. I'm just hoping that US-05 will not get too outrageous on weird phenol and esther production. Fingers crossed and chugging on a reasonably nice commercial craft brew

 

[jmos]

A thermometer on top of the bucket is really reading room temperature; the fermenting wort can be much warmer (like 10 degrees higher.) If you're fermenting at 75 or 85, you'll likely get off flavors. The suggestions above are a good idea to try to carry away some of the excess heat.

If you get a stick on thermometer strip of the side of the bucket, you'll get a better idea of the actual wort temperature.

 

[Ogri]

Forgot to say, though. Sometimes you can be exceptionally lucky and the yeast can produce some amazingly wondeful flavours and aromas into your beer, very unexpectedly, when ferm temps go a little,,,,,,,,,,,,,,,exotic......so you might have a brilliant beer that you can never, absolutely, replicate again at the end of the day.



I reckon my glass is half full

 

[MrAverageGuy]

If you have any way to install a thermowell in the bucket lid, it will be in contact with the wort - then you can simply put a thermometer down in from the top, and know your true fermentation temperature. Otherwise, you're really just guessing...

 

[mongoose33]

1. KNOWING your temps is important. Ambient isn't the same as the wort temp. I ferment in my basement, mostly, where ambient is 64-65. If I don't control temps, the wort will get up to 68-69 just from the heat of fermentation.

Even that is concerning to me, so I will get it down a bit further using my version of a swamp cooler (in pic below). I set the fermenter in an aluminum turkey pan ($1 at dollar store), drape an old t-shirt over it so it dangles into the water, and wet it down. It keeps the temps right around that 65-degree level.

Once active fermentation is complete I let the fermenter warm to about 71 for a couple days to allow the yeast to clean up, then let the fermenter sit for a couple more weeks at the ambient.

Since you're using a bucket you could wrap a towel around it using a bungee cord, or drape a large bath towel over it and use a couple bungees to bring the towel into contact with the bucket.

Good luck and welcome to home brewing!

PS: If you look closely, you'll see I have an Inkbird temp controller temp probe down the side of the swamp cooler; I used it just to monitor the temps, and if you can make it out, you'll see it shows 64.2 degrees (the 65 is a set point which is not being used).

 

[MrBJones]

Assuming you don't want the cost of an extra fridge or have the space it would take up, get one of THESE . I'm in Texas and am able to easily keep internal wort temps in the 60s (could go lower if I needed to). During active fermentation I use two frozen gallon milk jugs at a time, later just one; in either case I swap the jug(s) out once a day for new ones.