Mash Tun Temp Loss

[dreadhead]

Finally got a little esky mash tun setup for doing AG test batches, and just had a couple of questions before I have my first crack at AG, hopefully this week:

1) As a temperature loss experiment, I added 70 deg water to the tun and left it for an hour. Found that I lost 10 degrees by the end of it. Will this have any major effects on my beer? I assume it might make the wort a fair bit more fermentable.

2) When actual grain is mixed in with the water will this lessen the heat loss comapred to just water on its own? i.e will the grain husks and viscosity of the mash provide a bit of insulation from heat loss?

3) Anybody got any quick and cheap ways to minimise this heat loss if it is actually detrimental? preferably from stuff lying around the house.

Cheers guys :beer:

 

[chalky]

Hi Dreadhead,

I am no expert, but did you pre-heat the esky? A lot of the that temp loss probably happened heating the esky.

--Chalky

Finally got a little esky mash tun setup for doing AG test batches, and just had a couple of questions before I have my first crack at AG, hopefully this week:

1) As a temperature loss experiment, I added 70 deg water to the tun and left it for an hour. Found that I lost 10 degrees by the end of it. Will this have any major effects on my beer? I assume it might make the wort a fair bit more fermentable.

2) When actual grain is mixed in with the water will this lessen the heat loss comapred to just water on its own? i.e will the grain husks and viscosity of the mash provide a bit of insulation from heat loss?

3) Anybody got any quick and cheap ways to minimise this heat loss if it is actually detrimental? preferably from stuff lying around the house.

Cheers guys :beer:

 

[Bribie G]

When using an esky to do partials using a water bath with a smaller container floating in it, I always had to top up the bath with boiling water a couple of times in an hour mash. And that's with a genuine esky brand one which I assume is top of the market (it's SWMBO's, I didn't buy it but I think it was fairly exxy)

Although the esky is an insulated container, let's face it - it's really designed more to keep things cold and it's probably a given that you will have ice bricks, party ice etc in it to provide extra chilling.

So in the case of using it as a hot box, there's probably a case for lagging the esky further using an old sleeping bag or a doonah. I use a sleeping bag/esky with my urn and get about 2 degrees drop in an hour. If you could do that with your esky you should of course do even better. I know they do that regularly in the UK where ambients are a lot cooler.

And sure preheat it as far as poss.

 

[Gavo]

I have a 15 lt tun and a 50 lt tun. I have never done a test with water with either of these.... but I have found that with both I loose about 3 degrees C over the hour. Two degrees of this is lost in the first 10 min so a preheat would help. I wrap the tun in a towel or two and wrap up the ball valve to retain heat. In the 50lt I use a piece of polystyrene foam over the top of the mash to limit loss to the large amount of headspace.

With most eskies under $100 (they are really picnic coolers) the lid has no insulation so putting some extra insulation over the lid will help. Checking the mash temp after about 10 min and add extra hot water to compensate will also help. I have read on another thread that grain will also help a great deal with heat retention during the mash.

Cheers
Gavo.

 

[mckenry]

For anyone about to go AG, I bought a 60L Campmaster Marine Ice Box. It has a 4 day ice rating. I lose less than 0.5 of a degree in the hour. Very happy with it. Cost about $120 but worth twice that. Never worry about losing heat in the mash B)

 

[Maxt]

I drilled holes in my esky lid and used expanding foam. I also cover with a blanket. Went from 8degrees loss to now about 1hr over 90mins.

 

[haysie]

Finally got a little esky mash tun setup for doing AG test batches, and just had a couple of questions before I have my first crack at AG, hopefully this week:

1) As a temperature loss experiment, I added 70 deg water to the tun and left it for an hour. Found that I lost 10 degrees by the end of it. Will this have any major effects on my beer? I assume it might make the wort a fair bit more fermentable.

2) When actual grain is mixed in with the water will this lessen the heat loss comapred to just water on its own? i.e will the grain husks and viscosity of the mash provide a bit of insulation from heat loss?

3) Anybody got any quick and cheap ways to minimise this heat loss if it is actually detrimental? preferably from stuff lying around the house.

Cheers guys :beer:

Adding 70 degree water would give you roughly a mash temp of 62deg, so you only lost 2deg thereabouts over the hour? If you are losing 10deg after you add water stir up (mash) thats heaps too much.
Wrap your esky with some old blankets,towels anything laying around the house if you need to, I do in the winter here in Melbourne. Otherwise I allow about 8deg loss of temp between the adding(hlt) and stirring(tun) and if I screw up a deg or two, stir some more or grab the immersion heater.

 

[np1962]

Finally got a little esky mash tun setup for doing AG test batches, and just had a couple of questions before I have my first crack at AG, hopefully this week:

1) As a temperature loss experiment, I added 70 deg water to the tun and left it for an hour. Found that I lost 10 degrees by the end of it. Will this have any major effects on my beer? I assume it might make the wort a fair bit more fermentable.

2) When actual grain is mixed in with the water will this lessen the heat loss comapred to just water on its own? i.e will the grain husks and viscosity of the mash provide a bit of insulation from heat loss?

3) Anybody got any quick and cheap ways to minimise this heat loss if it is actually detrimental? preferably from stuff lying around the house.

Cheers guys :beer:

You will lose temp quicker with just water into a cold esky.
I heat my strike water about 5 degrees higher than I want, add to tun, close lid. After about 5 mins I crack the lid and let water temp drop to whatever Beersmith said I need and then add and stirr grain. Lose no more than 1C over 75mins.
The grains will help hold the temp.
If you have excessive head room in your tun a sheet of styrene foam cut to fit and pushed down onto mash will help with that. Sleeping bag wrapped around will also help but I have not needed to do this yet. Preheating the tun and lid makes the most difference IMHO

Nige

 

[mckenry]

I heat my strike water about 5 degrees higher than I want, add to tun, close lid. After about 5 mins I crack the lid and let water temp drop to whatever Beersmith said I need and then add and stirr grain. Nige

+1 This is excellent advice.
Others flood the grain (plenty of chat here if you search), but you need to be sure of your strike water temp, as you are using an esky.

 

[winkle]

I am currently using a 38 litre Keep Cool - preheated, it will only lose 1 C over an hour and that is without filling the lid with foam (which I will do one day).

 

[dreadhead]

Thanks for the ideas..... will try pre-heating the tun next time, and I have a sleeping bag lying around somewhere. Have already filled the lid with some expanding foam, so would hate to see the temp loss without it.

Cheers

 

[RetsamHsam]

For anyone about to go AG, I bought a 60L Campmaster Marine Ice Box. It has a 4 day ice rating. I lose less than 0.5 of a degree in the hour. Very happy with it. Cost about $120 but worth twice that. Never worry about losing heat in the mash B)

I have been thinking about upgrading from a 55L Willow to a 100L marine Ice box, I have seen ones with 10 day ice ratings..