Hot wort to fermenter?

wood&co · Nov 12, 2024

Morning all, proper newbie question…

I’m thinking about moving on from extract kits to my first mini-mash. Been looking at TMM recipes/kits and I have a stupid question!

The recipe calls for moving the hot wort from the pan to the fermenter post boil - will that be safe to do so? I envisage boiling wort melting a hole through the bottom of my (plastic) fermentation vessel… or at least disfiguring it in some way?! Am I being overly paranoid, or should I actually allow the wort to cool somewhat before transferring?

Thanks in advance!

Caramel Ox · Nov 12, 2024

Not safe - there will be a limit depending on the type of plastic but the best practice is to cool as quickly as possible post boil. If you can’t cool by moving it into the sink for example then leave to cool naturally.

MashBag · Nov 12, 2024

Don't.

Leave the lid on after boil. Have a cuppa, do the shopping. When you get back it will be about right.

For reference. I leave mine outside in a shed until the next morning.

wood&co · Nov 12, 2024

Seems like a consensus then!

So to be clear, post boil allow the wort to cool - then add to the fermenter, presumably add hot water along with cold in order to bring it up to pitching temp?

Or add the wort once it’s cooled sufficiently to add just cold and still be at pitching temp?

The only reason I say this is as I’ll be doing this on the hob I don’t want to leave it out overnight - a few hours isn’t a problem, by which time it will have cooled enough I guess?

Caramel Ox · Nov 12, 2024

What is your batch size? The consensus would be cool as well as you can - no chill is an option if it’s forced on you or if you decide to try it, it isn’t the default choice.

wood&co · Nov 12, 2024

Caramel Ox said:
What is your batch size? The consensus would be cool as well as you can - no chill is an option if it’s forced on you or if you decide to try it, it isn’t the default choice.

I’m thinking of trying something like this;

https://www.themaltmiller.co.uk/product/esb-mini-mash-kit/

So 21 litre batch - nothing crazy.

As you see from the recipe detail it clearly states “add the hot wort from the pan to your fermenter”

Anything else I should be aware of? It seems a lot of these resources leave a little to the imagination!

Bitter_Dave · Nov 12, 2024

It used to be common to buy or make boilers that were made out of plastic fermenters - indeed, my first first boiler was. Likewise, you add boiling water to kits in fermenters. Dave Line's books involved putting hot wort into fermenters and waiting until it cooled. If you have a standard plastic fermenter it would probably be fine with hot wort being added.

Caramel Ox · Nov 12, 2024

wood&co said:
I’m thinking of trying something like this;

https://www.themaltmiller.co.uk/product/esb-mini-mash-kit/

So 21 litre batch - nothing crazy.

As you see from the recipe detail it clearly states “add the hot wort from the pan to your fermenter”

Anything else I should be aware of? It seems a lot of these resources leave a little to the imagination!

The author is thinking that the fermenter is bigger than the boil pan and therefore easier to mix in - and they probably have steel available. Do the reverse and mix the extract into the hot wort then transfer, when you have made up with the cold water you will be about pitching temperature.

wood&co · Nov 12, 2024

Bitter_Dave said:
It used to be common to buy or make boilers that were made out of plastic fermenters - indeed, my first first boiler was. Likewise, you add boiling water to kits in fermenters. Dave Line's books involved putting hot wort into fermenters and waiting until it cooled. If you have a standard plastic fermenter it would probably be fine with hot wort being added.

That’s a good though RE boiling water, though as the wort is a high sugar solution would the temperature not exceed that of water?

Caramel Ox said:
The author is thinking that the fermenter is bigger than the boil pan and therefore easier to mix in - and they probably have steel available. Do the reverse and mix the extract into the hot wort then transfer, when you have made up with the cold water you will be about pitching temperature.

In all likelihood my fermenter will be bigger than my boiling pan… my fermenter is currently a wide neck 23litre fermenter (not the flimsy bucket type) - so mixing the LME would be far easier to do in this than in my pan…

I’m thinking I’ll just do my boil last thing and then leave it with the lid on overnight and make some excuse to the wife… then make sure I get the fermenter going first thing in the morning!

Thanks for all the input! It’s all very much appreciated I can assure you!

jof · Nov 12, 2024

Well I transfer my full volume wort to my fermenter at around 95' and haven't had a problem so far.
Advantages are that the hight temp will kill off anything that might be lurking round the tap that I couldn't get the cleaner into, and time.
This time of year, lid goes on & hot FV is moved to the kitchen & provides overnight heating while it cools & I take OG and add yeast in the morning.

If you are doing mini mash, as it's not full volume, you could add a few litres of cold water to your FV, then pour your hot wort in before topping up to required volume.

Clint · Nov 12, 2024

I think the only plastic you need to worry about are the clear plastic fermzilla types that sit on a frame not standard HDPE buckets.
Reading the recipe instructions the "hot" wort contact with the bucket will be short lived as you will be topping up to 21l with cold water. This will obviously cool your wort to somewhere near pitching temp. This time of year will have greater effect than in the summer. If it's not at pitching temp and you need to let it cool firmly fix the lid and fit the airlock as cooled wort before fermentation starts is most vulnerable to getting infected.
I'd definitely consider treating your top up water with a pinch of Camden tab to remove chlorine.
Also consider where your bucket is going to live while it does its thing as carrying a 21l =21kg bucket of sloshing liquid around isn't without problems!
Keep us informed!

wood&co · Nov 12, 2024

Clint & jof - thanks for the input.

Especially interesting regarding the Fermzilla as I’m thinking of getting one in the new year! So that will really nail down the ‘leave to cool’ train of thought!

I think for this brew I’m going to go for a combo - leave to cool for an hour to two then add to the fermenter along side a few litres of cold bottled water. That should make mixing in the LME easier also, and bring the temp down nicely.

When I get around to starting with the Fermzilla I’ll need to rethink by the sounds of things! Probably just leave it overnight I guess?!

Larse · Nov 12, 2024

Maximum temperature in a Fermzilla is 55°. Boiled wort cools to about 80° in about twenty minutes. You'd probably only need to wait a couple of hours for it to be down low enough to put in the Fermzilla and then adding cold water would take it down lower again.

Clint · Nov 12, 2024

Malt extract mixes easier into hot water and also if you warm it up.

Rodcx500z · Nov 12, 2024

Talking of firmzillas, i had 2 which i pressure fermented in they do a good job but' after 2 years the sell by date is up and they become normal fermenters, what i do now is brew outside let the wort cool to about 90c dump it in the fv lid on tin foil in the airlock hole leave it in the yard, by 8-9 o-clock pitch the yeast

wood&co · Nov 12, 2024

Rodcx500z said:
Talking of firmzillas, i had 2 which i pressure fermented in they do a good job but' after 2 years the sell by date is up and they become normal fermenters, what i do now is brew outside let the wort cool to about 90c dump it in the fv lid on tin foil in the airlock hole leave it in the yard, by 8-9 o-clock pitch the yeast

I was wondering how long they remain pressure rated for - but two years seems a tad short? I guess it depends on how frequently you brew - but still?!

I would think that so long as you maintain a medium to low pressure (5-10psi perhaps?) then they should last for a long long time, no? I shouldn’t think the yeast would perform well under much more pressure at any rate?

Really glad I mentioned the Fermzilla now! Learning a lot more than set out to, thanks again community!

Rodcx500z · Nov 12, 2024

One thing i will say is don't use the metal ball locks, i almost lost a full bottle of gas, i just used the ones supplied red and yellow plastic and never had a problem

Agentgonzo · Nov 12, 2024

Rodcx500z said:
Talking of firmzillas, i had 2 which i pressure fermented in they do a good job but' after 2 years the sell by date is up and they become normal fermenters

wood&co said:
I was wondering how long they remain pressure rated for - but two years seems a tad short

I'm with you here. That seems ridiculously short and basically a licence to print money if people keep buying them.

. My soda stream plastic bottles last well more than a decade, get used far more than a fermenter will and will probably hold far more pressure than a fermzilla will. I wonder whether it's only rated at two years because that's only as long as the manufacturer tested it for.

Laner · Nov 12, 2024

The manufacturer recommends the PET fermenters are retested after 2 years, the initial test is only ‘rated’ for 2 years thats not an instruction to bin it.

Larse · Nov 12, 2024

They're rated for up to 2.5 bars. Unless you're using them to dispense, they're never getting to that pressure.

Hot wort to fermenter?

Help Support The Homebrew Forum:

New Member

Landlord.

Landlord.

New Member

Landlord.

New Member

Regular.

Landlord.

New Member

Landlord.

Forum jester...🏅🏆

New Member

Landlord.

Forum jester...🏅🏆

Landlord.

New Member

Landlord.

Landlord.

Active Member

Landlord.

Similar threads

Join the conversation!

Join today and get all the highlights of this community direct to your inbox. It's FREE!