Maintaining Mash Temp in an Electric Urn

Post #1 made 15 years ago
Hi All. Quick question, I have a Birko urn with a temperature dial and was wondering if I was able to set it at my strike temperature and leave it on through the mash? Or do I have to hit my strike temp then turn the urn off and cover up for the mash time? Correct me if Im wrong, but I don't see it being a problem to set and forget about the temperature.

Cheers

Post #2 made 15 years ago
Fair enough question blair!

Strike temperature is heating enough strike water to a particular temperature so that when you add the grain, the heat absorbed by the cooler grain will lower the overall temperature to hopefully around mashing temperature. If you use less strike water it will need to be hotter, more and it will need to be cooler, vice versa with more or less grain. If you have some thermostat controlling the urn, leaving it at strike temperature means that as soon as you add the grain, it will start heating back up to that higher temperature where it all began.
Regardless of which method is used to heat the kettle, the principle remains the same- you want the mash to remain at certain temperature(/s) for certain durations throughout the entire mashing process, and evenly heated too. In most single infusion mashes, this is just one temperature around 65C, but could be anywhere from 60C to 70C. Now, if you set your urn at strike temperature, when the water temperature is stable and you add the grain, the temperature will drop and if you turned the urn off, it would hopefully be the desired single infusion mash temperature. With some insulation it should remain about the same temperature until you want to either lift & drain or mashout. If you leave the urn on at strike temperature though, it will heat the mash back up to that higher temperature, which is not what you'd want.

So, my answer is no, turn the urn off and insulate it. If there's some reason you can't insulate it, you'll need to continually add heat during the mash to maintain the mash temperature. There's also a problem with the distribution of the heat, after you add the grain, if you add heat at the bottom of the urn, it will not evenly distribute unless you stir it.

Hope this helps!
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Post #3 made 15 years ago
Agree with Ralph, you need to turn it off and insulate, unless you are going to stand there and stir for the entire mash. Not only for heat distribution, but also to prevent the bag being scorched by the heating element.

Much safer and easier to insulate.
"It's beer Jim, but not as we know it."

Post #4 made 15 years ago
Yes, I'm a Birko owner as well and I'm terrified of burning a hole in the bag, so I don't switch on the power unless the bag is clear of the element. One of the best and cheapest lagging methods is to go to a charity shop and buy a big XL size mens' padded ski coat - I paid about $5 for mine - and just dress the urn up like a little guy :lol:

However it's easy to apply a burst of heat mid-mash if you need to, by hoisting the bag off the element, apply heat, switch off power, lower the bag again and give a good stir. I find the best method is to use a paint 'pumper' that looks like a giant potato masher - It's also a good way to do a mashout by upping the total temperature to around 76 degrees.
Image
Last edited by Beachbum on 02 Aug 2010, 12:51, edited 6 times in total.

Post #5 made 15 years ago
Great question blair. I am going to change your topic title a tad and move it to the Electric BIABsforum as it will be more useful to other electric brewers there in the long run. (You were by no means incorrect though in starting this topic in BIABrewer.info and BIAB for New Members. It's our job to move new BIABrewer's questions to a better place when this is warranted.)

Great first topic blair,
Pat
Last edited by Pat on 02 Aug 2010, 21:26, edited 6 times in total.
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Post #6 made 15 years ago
The grain in the bag drops to the bottom of the urn and forms a blanket that will keep any heat from below trapped below the grain bed, and any heat produced may not even make its way to where the temperature probe is, resulting in a pocket of heat that will be far too high and result in poor efficiency as it denatures the enzymes around it, while the rest of the water will not be up to temperature.

I tried this with my first two brews, and then changed to insulating, and would never go back!

The best approach is to get to your strike temperature (approximately 2-3 degrees above your mash temp, turn off the element, add your grain, stir *thoroughly* and then insulate your urn.

I normally have my urn wrapped in a camping mat cut to shape (the lid is covered by a circle of camping mat material also) and then wrap a single bed doonah around the urn. I would be lucky to lose 1 degree over the 90 minutes this way in the normal temperature range in Adelaide, and perhaps more in winter.

Insulating makes it easier to repeat the process for consistent results, which improves your brewing, and makes better beer!

cheers,

Crundle

Post #7 made 15 years ago
just thought i'd post my idea for maintaining mash temp here.

I just did my first BIAB in an urn and thought of a plan should i need to increase the temp. I bought a frying basket and removed the handle. It fits nicely over the element and provides about a 5cm gap between the bag and element. Stirring is essential to distribute the heat.

Post #8 made 15 years ago
Quick question about using the element during mashing. Anyone use a pump (I know it does add equipment and complexity) to recirculate the mash instead of stirring? Seems like that would work well in maintaing temps???

Post #9 made 15 years ago
Just the liquid.

I imagine a bag sitting on top of something (cake rack/cooling rack) with the spigot underneath the bag pulling the wort form there and returning the wort to the top of the kettle. Kind of a HERMS without the Heat exchanger.

Cheers,
Jeff

Post #10 made 15 years ago
looBrew wrote:just thought i'd post my idea for maintaining mash temp here.

I just did my first BIAB in an urn and thought of a plan should i need to increase the temp. I bought a frying basket and removed the handle. It fits nicely over the element and provides about a 5cm gap between the bag and element. Stirring is essential to distribute the heat.
Sounds great loobrew. Let us know how it goes :luck:
Last edited by PistolPatch on 03 Nov 2010, 20:23, edited 6 times in total.
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Post #11 made 15 years ago
jhollist wrote:Just the liquid.

I imagine a bag sitting on top of something (cake rack/cooling rack) with the spigot underneath the bag pulling the wort form there and returning the wort to the top of the kettle. Kind of a HERMS without the Heat exchanger.

Cheers,
Jeff
to get it to work correctly, you have to get the liquid to pump out through the grain bed and not only above the grain. something like the German Braumeister.
but i like BIAB because i like "keep it simple". leave the pumps for the 3V brewers.
Last edited by shibolet on 04 Nov 2010, 03:55, edited 6 times in total.
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Post #12 made 15 years ago
shibolet wrote: but i like BIAB because i like "keep it simple". leave the pumps for the 3V brewers.
Ramen :thumbs:
Last edited by hashie on 04 Nov 2010, 05:18, edited 6 times in total.
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Post #13 made 15 years ago
I put on a BIAB demo day for a local brew club yesterday and using the urn, a sleeping bag and a duvet we had 1.3 degrees temperature drop in an hour from initial mash temp of 66 degrees, so no complaints.
I had thought of doing a sort of poor man's Braumeister using a March pump etc but when I worked out the prices, it was cheaper to buy a second urn and do double batches, as I've posted previously.

For improvements in quality and clarity, I've found that with my latest round of brews, rather than trying to alter my BIAB process itself, a better way to go was to use a better water supply (I bought a Reverse Osmosis water kit, the usual range of water salts and downloaded the excellent EzyWater calculator.) And faithfully do a mashout at 76 degrees. :drink:

Post #14 made 15 years ago
Good stuff BB! Hope the mob didn't try to string you up on the day, rather than the bag? Or both?! :P

1.3C drop is fine IMO, well done with that. I've no doubt that high- quality beer is achievable with 'standard' BIAB without resorting to recirculating and so forth. Paying attention to things such as water composition, process, quality ingredients and tailoring the recipe are all means to achieve that.
For anyone struggling with excessive heat loss, one means I've found helpful to minimise the heat loss even further is to pre- heat the lagging and the bench where it will rest for mashing. What I do with a single infusion is to overheat the strike water by 5-10C, put the insulation on the bench*, stockpot on, lagging on, then leave to cool down a bit. Obviously, the rules of thermodynamics do their thing and after a while the lagging heats up, water cools down and temperatures equilibrate. Then after 15 minutes or so I'll take the insulation off, reserve some of the water out in a jug and drop the bag of cracked grain in$, stir and after a few minutes to stabilise, measure the temperature. If its about right I'll just add the reserved water, if low then some boiling, high some cool, that way I get the chance to adjust the temperature to exactly where I want it, the stockpot is full to the brim as I want it, plus everything is at working temperature so heat losses should be minimal. I can then confidently walk away for an hour or more and leave it to do its thing, usually I get just a degree drop, often less during a 90 minute sacc rest, even in winter too I might add.
One other bonus is that it isn't critical to get the strike water temperature or volume just right as there is an opportunity to correct any over- or undershoot. Even with a brewing program the calculations and measurements were a real bother and gave me no end of headaches when I was starting out, but now since I get the chance to adjust both temperature and volume, it means far less fuss and bother when getting a batch underway.

* I don't mash on the stove where the stockpot is heated. Usually I'll heat some sparge water up before the mash is complete and because I'm using a gas stove, the risk that the lagging could catch fire was just too great so I moved over to the bench.
$ Thanks to who ever's tip that was, Bob wasn't it?! Just dropping the bag of grain into the kettle/ mash tun and a brief stir is so much easier than raining in while stirring the bejaysus out of it! :cool:

Oh, pardon the essay... :sleep:
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Post #15 made 14 years ago
jhollist wrote:Just the liquid.

I imagine a bag sitting on top of something (cake rack/cooling rack) with the spigot underneath the bag pulling the wort form there and returning the wort to the top of the kettle. Kind of a HERMS without the Heat exchanger.

Cheers,
Jeff
I hate to revitalize an old thread, but I had teh same exact idea. I already have a Chugger pump and was thinking of reciruclating from the very bottom (under the cake rack) into the center of the mash. All the while I would keep a very low flame (I am not using electric) as I am sure I would lose some temp as the wort transfrers through the pump.

Just curious if anyone has finally tried this.

John
Last edited by johnodon on 09 Aug 2011, 21:31, edited 6 times in total.
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