Aquarium heaters - yeast stress with direct wash contact?

[sphaleron]

Hey guys,

I've been using an aquarium heater to maintain the temperature of my washes to date. Temperature control as measured with a stick-on thermometer has been good. I have however started to focus on "yeast happiness" as part of my drive to produce neutral spirit with minimal heads and off-flavours. I am concerned about direct exposure of the fermenting wash to the aquarium heater. Even when the heater is fully submerged the temperature of the outer glass body is too much for me to hold So what is this doing to the yeast that comes into contact with this hot surface? In an aquarium you rely on a certain amount of circulation to ensure even temperature distribution. But in a plastic fermenting vessel I am not sure the required circulation exists.

What do you all think?

[Reverend Newer]

The heat produced by the submersible heater isn't causing your yeast any harm, water is a giant heatsink. Just produced 40 gallons wash in a blue HDPE barrel that turned out amazing using a 250 watt submersible heater. The yeast were super happy and produced a smooth product that finished dry and completely. Many folks use this type of heater with no issues.


To make your yeast happier try making a yeast starter, closely watch the starting pH and adjust it accordingly for the first 24 hours or so. Aerate the hell out of your wash before addding the yeast starter... I use a medical equipment air compressor, the air is filtered and will nearly blow the water out of the barrel the airflow is so powerful. I'd look into using boiled/pressure cooked wheat germ as a nutrient too and possibly invert some of your sugar to start. Also for sugar washes I am sold on Superstart yeast from Lallemand, it's so vigorous.


Hope you get the results you seek.

[DAD300]

check some of the posts on yeast stress. There are or maybe some positive flavor notes by a minimal localized stress.

[Pikey]

I think if you just go out there and explain to the yeast that you're trying to help and it's all for it's own good, It should keep the little loves happy and smiling

At least until you BOIL it !

[cranky]

The yeast actually create quite a bit of circulation. This video shows some of how that works.
https://www.youtube.com/watch?v=Ee6IUoWYybk" onclick="window.open(this.href);return false;" rel="nofollow
The first half of the video is a tomato ferment several days in after it has already settled down quite a bit but it is still very active and has lots of circulation.

[Truckinbutch]

I use a 32 gallon Brute nested inside a 44 gallon Brute for a fermenter . I wire the handles of both cans together to prevent the inner can from floating up . line the inner can with a 50 gallon clear garbage bag and stretch another over the top to exclude oxygen/ nasties . Punch 3/4 pinholes for pressure relief . Fill the outer can with water and put the heater in there . The heated water jacket will keep your yeast happy without being in direct contact with your ferment .
Been working fine for me for well over a year doing AG .

[SaltyStaves]

I use a 32 gallon Brute nested inside a 44 gallon Brute for a fermenter . I wire the handles of both cans together to prevent the inner can from floating up . line the inner can with a 50 gallon clear garbage bag and stretch another over the top to exclude oxygen/ nasties . Punch 3/4 pinholes for pressure relief . Fill the outer can with water and put the heater in there . The heated water jacket will keep your yeast happy without being in direct contact with your ferment .
Been working fine for me for well over a year doing AG .

I do similar, but I don't anchor down the inner drum. I siphon out the wash when it is done, so I take advantage of the positive buoyancy. The drum floats up as the wash comes out.
Its great for doing multi-gen UJSSM. I don't have to break my back scooping out the spent corn.

[Bushman]

Nice idea Truckinbutch! Not sure it would float up when full but weighting the bottom would be another solution.

[Truckinbutch]

Nice idea Truckinbutch! Not sure it would float up when full but weighting the bottom would be another solution.

It will actually bulge the sides of the outer barrel when full and rise higher than I want to reach when the clear liquid is racked off and I need to dip and squeeze . Wiring the handles together covers both issues .

[Blarney Stoned]

I use a 32 gallon Brute nested inside a 44 gallon Brute for a fermenter . I wire the handles of both cans together to prevent the inner can from floating up . line the inner can with a 50 gallon clear garbage bag and stretch another over the top to exclude oxygen/ nasties . Punch 3/4 pinholes for pressure relief . Fill the outer can with water and put the heater in there . The heated water jacket will keep your yeast happy without being in direct contact with your ferment .
Been working fine for me for well over a year doing AG .

Wattage of heaters ?

Thank you, Sir.

[MoonBreath]

With repetition, most yeasts I've found will aclamait to most folks varied elements and conditions..
Distillers yeast is proven choice for me.
Ok here we go..Yeast are like goldfish, requiring certain temps, oxygen, and nutrient..They will adjust (within margin), to evolving variables and techniques..Likewise what stresses goldfish basically stresses yeast.
Aquarium heaters don't know the difference between aquarium gravel or corn..When a goldfish gets close to the heater, it doesn't die.
My aquarium heater is set on 86°, with the peak working temp 93-94°..I've found using bare minimum of yeast With instructed amount of yeast nutrient w/ag, leaves a clean, dry finish..I also aerate with medical oxygen.
Now heres another thing I feel strong about..
Thats fermenter Shape..Tall conical designs work harder fermenting bottom up, conducive to uneven heat gradient or distribution, causing stress, and unfinished dry ferments.
Fermenters that are Longer than Tall are better choices, conducive to complete and stress free ferments..Also transferring heat thoroughly..The reasons for conical choice for pros is the Space savings..Still some use large round wooden fermenters, and have seen large round stainless fermenters that were half the height as the length..All my yrs of readn learnt me the info, common sense led me to the practice..I use sterilite 20 gal totes..Thinkn Compleat Distiller or Parent site the source.
My heaters are 300 w.

[Truckinbutch]

I use a 32 gallon Brute nested inside a 44 gallon Brute for a fermenter . I wire the handles of both cans together to prevent the inner can from floating up . line the inner can with a 50 gallon clear garbage bag and stretch another over the top to exclude oxygen/ nasties . Punch 3/4 pinholes for pressure relief . Fill the outer can with water and put the heater in there . The heated water jacket will keep your yeast happy without being in direct contact with your ferment .
Been working fine for me for well over a year doing AG .

Wattage of heaters ?

Thank you, Sir.

350 watt is my favorite at present . This has been a dance I learned as I go . I started with 50 watt because I knew no better and immersed them in mash . Those formed an insulating clot that gave little benefit to the overall ferment . Been a long journey to where I am now .

[Blarney Stoned]

Thanks, TB. I have a couple of those heaters in the 3/400 watt range somewhere around here. Might give it a try.

Usually have an 8 gallon UJ going 24/7 year 'round in my smallish chest freezer fermentation box.Works very well. Just enough to have fun with.

Good day to ya, Sir.

[distiller_dresden]

Hi! I've been using an aquarium heater with no problems for my ferments, but I've noticed on my latest corn mash, all grain (first all grain with lots of grain) that my temp on top (with one of those point and shoot laser thermos) is 69-70, but my heater is set for 75*. My ferment is doing fine, and granted the temp is on top of the grain must/cap, which is likely holding in some heat.

But it got me to thinking, should I pick up one of these?

Hydor Koralia Nano Aquarium Circulation Pump

It's basically a little submersible fan motor which just looks like a boat motor and pushes liquid, to create circulation? Or would that not even really work on my grain heavy corn mashes anyways, and be just something else that could break/introduce unwanted infection?

[Truckinbutch]

I think you would be better served with a clear water jacket with the aquarium heater . With my setup I rack 12 gallons of settled clear ferment from 30-32 gallons . The rest needs to be squeezed and strained in the mop bucket . Generally I get 10-12 gallons of thick , murky liquid for the thumper charge .
FreMountainHermit and I both found that putting a heater directly into the mash caused the grains to coagulate aroud the heater and cause an isolated hot pocket and a chilled mash outside that limited heat area .

[distiller_dresden]

Hey TB, for a clear water jacket, what do you do? Could I pop a hole in the top of a 32oz jar, seal it with silicone, feed the cord through, fill the jar with water to the toppy-top, and set it in my mash tub?

Also, I just had a problem with a new heater, I set it on the cord, it has one button, and I set it to 21c, fine, then this morning had a hole in the middle of my ferment, heat check it was cooking at 88. The damn thing set itself to max. You can read about it in my cornflakes/corn thread. Pulled that heater for now, on my old one at the moment.

[SaltyStaves]

Hey TB, for a clear water jacket, what do you do? Could I pop a hole in the top of a 32oz jar, seal it with silicone, feed the cord through, fill the jar with water to the toppy-top, and set it in my mash tub?

I use a 32 gallon Brute nested inside a 44 gallon Brute for a fermenter .

No one said anything about glass jars. Water jacket = Water bath.

[distiller_dresden]

Thanks for the obvious heads up.

I was thinking 'jacket' as in sink it in a bubble of water to create a bigger heater that couldn't be as affected by mash and would sit above the grain settling.

[SaltyStaves]

That would probably explode glass into your wash.

[Avo]

Hey guys,

I've been using an aquarium heater to maintain the temperature of my washes to date. Temperature control as measured with a stick-on thermometer has been good. I have however started to focus on "yeast happiness" as part of my drive to produce neutral spirit with minimal heads and off-flavours. I am concerned about direct exposure of the fermenting wash to the aquarium heater. Even when the heater is fully submerged the temperature of the outer glass body is too much for me to hold So what is this doing to the yeast that comes into contact with this hot surface? In an aquarium you rely on a certain amount of circulation to ensure even temperature distribution. But in a plastic fermenting vessel I am not sure the required circulation exists.

What do you all think?

I picked up on this post, because I use x3 100w aquarium heaters (glass) in my 25 litre fermenters. Although they have their own thermostats, I use an Inkbird with a probe in one fermenter as a 'fail safe' - the other two that I use, I plug into adapters plugged into the Inkbird heating socket. They all switch on/off together through the Inkbird. I have been thinking about the 'water jacket' method, but simplyfying things a bit and making it more portable. I thought of using air conditioning plastic duct tube. The idea would be to suspend the tube vertically in the fermenter, the length to rise above the wash level to the underneath of the lid; which would secure the tube steady, the bottom would be capped. The tube filled with water and the aquarium heater suspended in the tube. This would have a more gentle heating action on the yeast, which would not come into contact with the heaters - so the water jacket as such, would be inside the fermenter bucket. I plan to give it a try.

Avo

[NZChris]

That sounds like a lot of trouble to go to compared to insulating the bucket to stop the heat the yeast creates from escaping.

[Avo]

That sounds like a lot of trouble to go to compared to insulating the bucket to stop the heat the yeast creates from escaping.

I appreciate your comment Chris. I am a bit of an experimenter, and seek to get absolute temperature control.
I already have the heating kit and tube, so something for me to try out. If it works it would be less trouble than putting
a fermenter into another container. I have thought for a long time, that the yeast would do better to not be in contact
with the aquarium heaters. As another commented "Be kind to your yeast".

For those quick of the mark, they may have thought, the tube will displace the ferment wash and raise the level.
My brain must have been working through the night, as I awoke with this in mind.
I immediately got my fermenter and tube and checked. The tube held/displaced 4 litres of water/wash.
Fortunately in my favour, the fermenter was wrongly calibrated and there will be enough headspace.
The other consideration is the tubes resistance to low alcohols, the tube is white and very hard plastic, it would need to
be a 'HDPE' (PET) type suitable for fermenters - I will look into this.

Another interesting thread on the topic: viewtopic.php?t=47162

[Saltbush Bill]

Did a very similar thing to keep my last angel yeast ferment cosy and warm.
Put the fish tank heater in a cheap tall glass vase full of water. Put some gravel in the bottom of the vase as ballast to hold it down......worked like a charm.

[Avo]

Did a very similar thing to keep my last angel yeast ferment cosy and warm.
Put the fish tank heater in a cheap tall glass vase full of water. Put some gravel in the bottom of the vase as ballast to hold it down......worked like a charm.

Hi Saltbush Bill,

Excellent idea, better than mine. I had trouble tracking down HDPE tube, it would have been expensive.
Your fermenter looks shallow, my buckets are 44cm deep. However, I discovered some cheap vases/cylinders
40cm high which are perfect. The glass being so much more hygenic. I note you are also using the supplied
suction cups. Some have said in small confined areas the heaters would blow, but you haven't had any issues
with your setup. I couldn't see it myself, the surrounding wash would conduct the heat away; they also have
their own internal thermostat too. I had ordered some very cheap (PET) 5 litre fermenters which I was going to
seal the heater in, but I shall ditch that idea and use them for small experimental fermentations.
You have saved me a lot of time and trouble. I have ordered a cylinder to trial. Many thanks.

p.s. The mention of 'Angel' yeast was interesting: https://en.angelyeast.com/products/dist ... fuels.html

[Saltbush Bill]

The cooler / esky has a volume of 130L
Ive since bought a taller vase.
The vases come from " cheap shops" "two dollar shops"
"Reject shops" not sure what they are called in other parts of the world.
I can now use this set up to heat washes of up to approximately 90L

[The Baker]

The cooler / esky has a volume of 130L
Ive since bought a taller vase.
The vases come from " cheap shops" "two dollar shops"
"Reject shops" not sure what they are called in other parts of the world.
I can now use this set up to heat washes of up to approximately 90L

A good idea.

Geoff

[Avo]

Focus on "yeast happiness" as part of my drive to produce neutral spirit with minimal heads and off-flavours. I am concerned about direct exposure of the fermenting wash to the aquarium heater. Even when the heater is fully submerged the temperature of the outer glass body is too much for me to hold So what is this doing to the yeast that comes into contact with this hot surface?

For some time, I have not been getting the expected ABV from my simple sugar washes. I use EC-118, plus the other family of products, Go-Ferm & Fermaid 'O' ( I was wanting to get away from DAP) I have recorded S.G's / adjusted Ph levels etc etc.
This low abv is the main reason for me to look into fermentation temp'& control. Today, I checked out the surface temperature of one of my aquarium heaters suspended in water, I was surprised to see the temperature at a minimum of 40c + I suspect that on contact, there is a possibility that some yeast could perish and thereby stop maximum yeast growth. - I might add, this seems to be since I started using aquarium heaters.
As described in my previous comment, this is why I am going to isolate the heaters from direct contact with the yeast population. - If I get good results it would point this problem as being caused by the aquarium heaters & should solve my low abv problem with sugar washes.

[Avo]

As a follow up to my last post:

I got my glass vase through the post today, it's a perfect cylinder. I thought I would try it out in
a 25 litre fermenting bucket. It's a perfect fit. The lid actually holds down the cylinder, you
can see the silhouette through the lid.
I set my Inkbird & aquarium heater to 27 Deg C - I placed the probe in the cylinder with the heater.
I used another thermometer with a probe which I placed in the bucket of water. I got a very stable
temperature control. I am very happy with the setup, the next step is to do a ferment.

[NZChris]

Check the temperatures at the top and bottom of the fermenter.

[Avo]

Check the temperatures at the top and bottom of the fermenter.

I did as you suggested this morning. I set the thermometer probe at the bottom,
recorded the temp, then raised the probe to the top.
Naturally, the surface temp was 3 deg C higher. I did not think this too big a fluctuation.
The bucket was standing overnight (on a foam pad) on granite tiles on the ground floor,
and susceptible to nightime drops in temperature. I would eventually put an insulating
jacket around the fermenters which might lessen this differnce slightly.
I'm sure the active yeast will also help too.