Biab - Maintaining Mash Temperature

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stowaway

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Currently I leave the flame on and turn it on and turn it off as needed to maintain the temperature.

I really have my doubts about how I can mash with the flame off just by putting a rug around my Aluminium Stock Pot..

Who does it that way? Get the temp to say 67degrees and just insulate and holds the temp at 67 without flame?

I honestly think over the hour period it'd drop atleast by 10degrees.

But then others have said that by leaving the flame on i get an inaccurate temp reading as it is hotter at the bottom..
 
hi i did a 75 minute mash the other day and my mash tun has no insulation and the temperature only droped buy 1-2 deg by the end of the mash
i think insulation is not really needed as the grain helps insulate.
cheers paul
 
with biab the thermal mass of the mash is much greater than with a traditional mash cause the water to grain ratio is much higher, i loose around 1.5-2*c over a 75 minute biab mash not something i'm too concerned with.
 
Hey buddy,

I simply chuck a rug and a sleeping bag over my ss pot and leave it for an hour, then bring it back up after an hour (usually 1-2 degrees), havnt had any problems this way...

Ive heard that aluminium is a better thermal conducter than ss, so in theory I think it should hold temp better than ss, so you should be fine with just throwing a rug or whatever over it (sleeping bags are really well insulated and work mint)

Cheers


Currently I leave the flame on and turn it on and turn it off as needed to maintain the temperature.

I really have my doubts about how I can mash with the flame off just by putting a rug around my Aluminium Stock Pot..

Who does it that way? Get the temp to say 67degrees and just insulate and holds the temp at 67 without flame?

I honestly think over the hour period it'd drop atleast by 10degrees.

But then others have said that by leaving the flame on i get an inaccurate temp reading as it is hotter at the bottom..
 
Ive heard that aluminium is a better thermal conducter than ss, so in theory I think it should hold temp better than ss

Well you're half right.

Aluminium has a higher thermal conductivity than SS, so more heat will transfer through the Aluminium under the same conditions --> more heat loss with Aluminium.
 
Currently I leave the flame on and turn it on and turn it off as needed to maintain the temperature.

I really have my doubts about how I can mash with the flame off just by putting a rug around my Aluminium Stock Pot..

Who does it that way? Get the temp to say 67degrees and just insulate and holds the temp at 67 without flame?

I honestly think over the hour period it'd drop atleast by 10degrees.

But then others have said that by leaving the flame on i get an inaccurate temp reading as it is hotter at the bottom..

Have you tried it??

I have watched at least 10 brews where the 76L aluminium pot was brought to temp, insulated and simply checked every now and again for temp (adjusting if required) And that was only with a couple of layers of cardboard as insulation. Talking a degree or two here and there.

I also know that people who don't insulate the pot at all & are generally only having to switch on the flame every now and then in order to maintain temp, and that quite a few don't even bother with the every now and then bit.

I can't actually think of a worse way to run a BiaB mash than to leave the flame on for the whole time - unless you are constantly stirring, you have no idea what the temperature actually is. If you want to constantly stir... fair enough, but IMHO you are making your life unnecessarily hard.

If your pot drops by 10 over an hour mash, you either mash in the antarctic, or your pot is magic in some way, and it probably isn't, so don't worry.

Strike and hydrate/stir - adjust to temp if you missed it - insulate - check temp and adjust if needed at the 10minute and 20 minute mark, then ignore it for the rest of the mash. If you are seriously worried - check the temp more often for a few brews, until you either confirm that you have to worry, or discover that you don't.

The vast majority of the action will be over by the 20min mark and the rest of the hour is just to finish off completely - it might drop a degree or two over that period, but it wont really matter all that much to the final result.

The only way you are going to find out is to try - all the advice in the world isn't going to help a lot, because everyone's system is different. We cant tell you what will happen on yours, only what we have seen happen on ours.

TB
 
I honestly think over the hour period it'd drop atleast by 10degrees.

I recorded my temps as I stirred my last BIAB. I lost half a degree by the twenty minute mark, by which time most of the conversion is meant to have finished. At the end of a sixty minute mash, I had lost a total of 1.5 degrees.

I wrap my kettle in a 12mm camping mat and don't apply extra heat during the mash. Also, my BIAB mash would probably have less thermal mass than most since I hold back 7 litres (the capacity of a little urn which I have) and dump it in at the end for a mash out.
 
Hi

Im up to batch 4 now and I have a insulated electric 60L Ali boiler. Before insulation I use to lose 4-5c ove 90 min(I stir every 5 min for 20min then every 20) with no heat applied. Now I have added a layer of foil bubble wrap and a 12mm camping mat and I am only losing 0.5 to 1c over 90min depending on how much I stir.

Hannes
 
Hi

Im up to batch 4 now and I have a insulated electric 60L Ali boiler. Before insulation I use to lose 4-5c ove 90 min(I stir every 5 min for 20min then every 20) with no heat applied. Now I have added a layer of foil bubble wrap and a 12mm camping mat and I am only losing 0.5 to 1c over 90min depending on how much I stir.

Hannes


Do you insulate the lid?
 
I use a couple of beach towels tied around the outside of the pot and another one folded on top of the lid.
Seems t hold temp really well and only 1 maybe 2 degrees loss.

Horses for courses with what you have handy at the time.



edit: spllin and grmmr
 
Yes the lid is the most important. Double insulation if you can.

Hanzie
 
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