Is Fermentation Faster At A Constant Temp?

[Greg Lawrence]

Howdy all

3 questions here

Due to the hot weather lately (until this week that is) I havent been brewing as I have not got a fermenting fridge.
Due to the lack of brewing, my kegs have all run dry (must have evaporated), so I decided to do a couple of brews and put the fermenters in my kegerator, a chest freezer with fridgemate now set at 21 degrees for ales.
In the past, fermentation has taken as long as 3 weeks (in the garage), but at a constant 21 degrees in the chest freezer, they seem to be almost done in a week. Would this be because low overnight temps slow down the fermentation?
I havent checked with a hydrometer yet, but that is my next problem. I usually pour out of the tap into a test tube, but as the fermenters are at the bottom of the chest freezer I may have to somehow syphon or suck some out with my keg filling hose.
I really didnt give it too much thought as my next problem is going to be lifting the fermenters out to a higher level to fill the kegs without disturbing the yeast cake too much. Any suggestions?

Any advise would be appreciated.

Gregor

 

[Adamt]

Fermentation will run faster with increased temperature. The lower overnight temperatures will slow down fermentation and could drop some yeast out which could also see fermentation slowing if it's significant enough.

As for getting the fermenters out... strong lower back!

 

[muckey]

I really didnt give it too much thought as my next problem is going to be lifting the fermenters out to a higher level to fill the kegs without disturbing the yeast cake too much. Any suggestions?

either get some help to lift the fermenter or syphon some out before trying to lift them yourself. You probably dont have enough height to empty them completely but could probably get them half full.
Alternatively, lift them yourself and then complain about you sore back

 

[raven19]

Fermentation will run faster with increased temperature. The lower overnight temperatures will slow down fermentation and could drop some yeast out which could also see fermentation slowing if it's significant enough.

As for getting the fermenters out... strong lower back!

+1.

You could siphon some of the beer into a secondary fermentor prior to lifting to reduce back injuries.

Or just whip the lid off use a sanitised cup and get a sample to test. Using all sanitary methods necessary of course.

Edit: Typing too slow - what Muckey said!

 

[Greg Lawrence]

As for getting the fermenters out... strong lower back!

Its not the physical part I am worried about, but more the diisturbing of the yeat cake. Might have to chuck a few litres.

 

[buttersd70]

Howdy all

3 questions here

Due to the hot weather lately (until this week that is) I havent been brewing as I have not got a fermenting fridge.
Due to the lack of brewing, my kegs have all run dry (must have evaporated), so I decided to do a couple of brews and put the fermenters in my kegerator, a chest freezer with fridgemate now set at 21 degrees for ales.
In the past, fermentation has taken as long as 3 weeks (in the garage), but at a constant 21 degrees in the chest freezer, they seem to be almost done in a week. Would this be because low overnight temps slow down the fermentation?
I havent checked with a hydrometer yet, but that is my next problem. I usually pour out of the tap into a test tube, but as the fermenters are at the bottom of the chest freezer I may have to somehow syphon or suck some out with my keg filling hose.
I really didnt give it too much thought as my next problem is going to be lifting the fermenters out to a higher level to fill the kegs without disturbing the yeast cake too much. Any suggestions?

Any advise would be appreciated.

Gregor

Gregor,
fermentation will be quicker if it's hotter....but this isn't always optimal, of course. But if temp is constant, it will be a more effective fermentation, as the yeast will be happier and healthier, which will speed things up. Combined this with a reasonably warm ferment temp (dependant on what the yeast is, and what you want out of it), and you get a much faster fermentation. Constant 21 could be good for a characterful English yeast. For more neutral yeast, slightly lower temp, say 18C in the example of us05, is better. But either way, constant temperature conditions are (usually, there are always exceptions) best.

For the sample, either sanatise your racking tube, and draw a sample with that (by just submerging it, putting your thumb over the end then lifting it out) or a sanatised turkey baster or sanatised soup ladle should be fine.
Getting it out of the chesty is another issue.....just have a think before you do it, and organise it so it can be lifted out in one continuous movement. (if possible)

 

[Greg Lawrence]

Gregor,
fermentation will be quicker if it's hotter....but this isn't always optimal, of course. But if temp is constant, it will be a more effective fermentation, as the yeast will be happier and healthier, which will speed things up. Combined this with a reasonably warm ferment temp (dependant on what the yeast is, and what you want out of it), and you get a much faster fermentation. Constant 21 could be good for a characterful English yeast. For more neutral yeast, slightly lower temp, say 18C in the example of us05, is better. But either way, constant temperature conditions are (usually, there are always exceptions) best.

For the sample, either sanatise your racking tube, and draw a sample with that (by just submerging it, putting your thumb over the end then lifting it out) or a sanatised turkey baster or sanatised soup ladle should be fine.
Getting it out of the chesty is another issue.....just have a think before you do it, and organise it so it can be lifted out in one continuous movement. (if possible)

Thanks Butters

It was a Safale S04 yeast. From memory it said 15 to 24 degrees. Do you think 18 may have been a better temp?

 

[Adamt]

I tend to crash chill my ferments in my chest freezer-come-fridge to aid sedimentation before lifting out... I never have any troubles with extra wastage due to distrubing the yeast cake.

 

[muckey]

butters and a long straw works really well as a syphon. He's a bugger to sanitise though

 

[Greg Lawrence]

I tend to crash chill my ferments in my chest freezer-come-fridge to aid sedimentation before lifting out... I never have any troubles with extra wastage due to distrubing the yeast cake.

Thanks Adamt

I have heard of that before, but for some reason thought tht was for lagers, so didnt mention it in fear of being shot down as a novice. I will try crash chilling before lifting out.

 

[Gavo]

I was fermenting during spring in the shed; desert weather here, cold at night and warm in the day. Not too warm though. Ferments were taking up to two weeks. I was really surprised when I got a tempmate and fermenter fridge how much faster ferments happened. Usually under 6 days at a constant 18 degrees C.

Gavo.

 

[Greg Lawrence]

I was fermenting during spring in the shed; desert weather here, cold at night and warm in the day. Not too warm though. Ferments were taking up to two weeks. I was really surprised when I got a tempmate and fermenter fridge how much faster ferments happened. Usually under 6 days at a constant 18 degrees C.

Gavo.

Well this is great news. Because of a 3 week turn around I sometimes had 4 fermenters on the go at once to keep the supply and demand at an equilibrium. If I can get a 1 week turn around using a fermenting fridge, I am definately going to get one!

 

[Screwtop]

I tend to crash chill my ferments in my chest freezer-come-fridge to aid sedimentation before lifting out... I never have any troubles with extra wastage due to distrubing the yeast cake.

+ 1

Chill for a few days, lift out and fit sanitised racking hose to tap, pour gelatine solution into the bottom of a sanitised keg and rack to keg, close up and force carb, put in the serving fridge, it will be ready to drink in 24 hrs (toss the first glass of gelatine and yeast). If you prefer to age/condition the beer then wait a few weeks before serving, check carbonation level frequently if the keg is not left on the gas.

Cheers,

Screwy

 

[Greg Lawrence]

+ 1

Chill for a few days, lift out fit sanitised racking hose to tap, pour gelatine solution into the bottom of a sanitised keg and rack to keg, close up force carb and put in the serving fridge, will be ready to drink in 24 hrs. Toss the first glass of gelatine and yeast. If you want prefer to age/condition the beer then wait a few weeks before serving, check carbonation level regularly.

Cheers,

Screwy

Thanks Screwy

But could you tell me more on the gelatine solution in the keg. I used to use one teaspoon of gelatine in a cup of hot water in the fermenter a couple of days before bottling, but have never heard of it in a keg. What proportions of gelatine to water would I use?

 

[buttersd70]

Do you think 18 may have been a better temp?

Not necessarily. It depends on what flavour profile you are wanting from the yeast. Cooler temperatures will give a 'cleaner' result. (I hate that term...it can give a false impression that anything not 'clean' is bad, and thats not necessarily the case.) Warmer temperature will lead to more fermentation bi-products, such as esters, for example. With an English yeast like S04, the production of esters etc. may well be desirable. In many English style beers (and others, hefewiezens for one example), this type of character is appropriate, and there are times when the 'clean' flavour of a lower temp or a more neutral yeast are not appropriate. So, it depends on what you are brewing. Personaly, I like my English Bitters with a nice ester profile, so I often ferment warm (relatively speaking, that is. Towards the upper end of the reccomended temperature profile for the yeast.) It's a matter of familiarising yourself with the specific yeast strains, to see what works best.

butters and a long straw works really well as a syphon. He's a bugger to sanitise though

<_<

 

[Greg Lawrence]

Thanks Screwy

But could you tell me more on the gelatine solution in the keg. I used to use one teaspoon of gelatine in a cup of hot water in the fermenter a couple of days before bottling, but have never heard of it in a keg. What proportions of gelatine to water would I use?

Dont worry Screwy,

i just used the search function and found the Screwy method in great detail Link
I will give it a try.

 

[rich_lamb]

Butters has it right - the temp will control the rate AND the character.

IMHO; if you have a choice go for a slightly cooler ferment temp. A warmer temp will give a vigorous fermentaion which finishes quicker but is not necessarily better. Fermentation is thermally unstable - if you ferment a couple of degrees warmer it will take off and self heat, unless you have VERY responsive temperature control.

Some of the flavours from a warm ferment - fusels or excessive fruity/bananas or whatever - can make a great beer into just a good beer. I would err on the side of cooler.

 

[Mantis]

I have been making fairly constant type brews that finish at 1014 or very close to after two weeks in fermenting in the family room with wildly fluctuating temps.
Got a freezer and hooked it up as a fermenting fridge. First brew in there finished at, yes 1014 in 7 days.
I have a wheat beer in there now and last night when getting a brew I could hear it popping away at a rate of knots. This at 18C. I think US-05 likes the constant temp.
(yeah, I know, US-05 in a wheat beer. I didnt have anything else, so call it a wheaty gold)
Damn sure am happy with the new temp control

 

[buttersd70]

if you ferment a couple of degrees warmer it will take off and self heat,

Yea, if going warm, you need to be careful about this.....occasionaly one will get away from you (even if you have experience fermenting warm), and turn a great beer into a disaster.