Robobrew as a self heating Mash tun?

[Ch4rd]

might be an odd question but here goes...

I have a 3 pot system with a 50L kettle and 45L square coolbox mash tun.

my last brew was supposed to be about 1.060 but I only managed 1.042 from a 10kg grain bill - about 50% efficiency.

i think my mash tun is at fault (square design and bazooka filter not as good as a cylinder apparently) and no way of controlling temp - so i thought i'd upgrade to a shiney mash tun and look at HERMS options.

its looking quite pricey and as I see it the robobrew (about 35L) could in theory be used as a big mash tun could it not?

then once its all done, just pump it all into my kettle?

it might be madness but then i would be able to do smaller 1 keg brews on the robobrew and then bigger 2 keg brews in the robobrew/kettle.

let me know thoughts/opinions/examples of people that have tried this and failed miserably

 

[VikeMan]

i think my mash tun is at fault (square design and bazooka filter not as good as a cylinder apparently) and no way of controlling temp - so i thought i'd upgrade to a shiney mash tun and look at HERMS options.

There's nothing inherently wrong with rectangular a mash tun configuration or with bazooka filters.

Are you having problems hitting your initial mash temperature? If so, that's calculation issue and not a hardware problem.

Or are you losing too much heat over the length of the mash? Or...?

 

[Ch4rd]

a bit of both @VikeMan - its also that sometimes by equipment is cold (garage in the UK) and sometimes I remember to bring it in - same goes for the grain so the calculators are usually a degree or two off in either direction)

i managed 65oC (after adding a couple of kettle fulls of water) at the start so not too terrible but then it did drop away on me and there was no way of bringing temp back up. id also like to recirculate with my pump but don't want to loose more temp doing that - hence the idea of going down the HERMS route.

even then I'm not sure a few degrees alone can account for such a poor efficiency. I've done a LOT of brews but this was my first attempt at a double batch of higher gravity beer.

 

[VikeMan]

a bit of both @VikeMan - its also that sometimes by equipment is cold (garage in the UK) and sometimes I remember to bring it in - same goes for the grain so the calculators are usually a degree or two off in either direction)

Well, if you forget to bring your equipment and grains in to warm up, you could still switch temperatures in the calculator. And make sure you're using a calculator that actually cares about the tun's temperature and heat capacity.

i managed 65oC (after adding a couple of kettle fulls of water) at the start so not too terrible but then it did drop away on me and there was no way of bringing temp back up. id also like to recirculate with my pump but don't want to loose more temp doing that - hence the idea of going down the HERMS route.

So, how many degrees did you lose?

even then I'm not sure a few degrees alone can account for such a poor efficiency. I've done a LOT of brews but this was my first attempt at a double batch of higher gravity beer.

Higher gravity beers (i.e. large grain bills), all other things being equal, have lower mash efficiencies than smaller grain bills. Recipes with larger grain bills (but the same pre-boil volume) require more total water, because of more grain wort absorption. So the ratio of absorbed wort to total wort (including absorbed) is larger. Therefore a smaller percentage of the total sugars/dextrins produced makes it to the kettle). It sounds like part of the problem was in expectations.

 

[Ch4rd]

i appreciate the advice and suggestions but question still stands though ... robobrew... could i use it effectively as a mash tun?

 

[VikeMan]

i appreciate the advice and suggestions but question still stands though ... robobrew... could i use it effectively as a mash tun?

I don't own one, but the way I see it, it is a mash tun, so I don't see why not.

 

[Sammy86]

might be an odd question but here goes...

I have a 3 pot system with a 50L kettle and 45L square coolbox mash tun.

my last brew was supposed to be about 1.060 but I only managed 1.042 from a 10kg grain bill - about 50% efficiency.

i think my mash tun is at fault (square design and bazooka filter not as good as a cylinder apparently) and no way of controlling temp - so i thought i'd upgrade to a shiney mash tun and look at HERMS options.

its looking quite pricey and as I see it the robobrew (about 35L) could in theory be used as a big mash tun could it not?

then once its all done, just pump it all into my kettle?

it might be madness but then i would be able to do smaller 1 keg brews on the robobrew and then bigger 2 keg brews in the robobrew/kettle.

let me know thoughts/opinions/examples of people that have tried this and failed miserably

The Robobrew is an all in one system...meaning you mash and boil in the same "pot." Why you want to transfer out when you can just pull out the mash basket, sparge and then boil is beyond me.

 

[RePete]

i appreciate the advice and suggestions but question still stands though ... robobrew... could i use it effectively as a mash tun?

Yes. Although you suggest that your idea is to use it as a mash tun when you do 10 gallon batches? Is that what you mean by a 2 keg brew? The 35L is really designed for 5 gallon batches. And the grain capacity is limited. The stated limit of a grain bill is 18 lbs, although some of us have fit slightly more occasionally. 18 lbs isn't a large grain bill for a 10 gallon batch. You might want to consider the 65L version.

 

[chipmunk]

The stated limit of a grain bill is 18 lbs, although some of us have fit slightly more occasion

You might be able to increase the grain volume by not using the basket, and instead use a BIAB bag inside the pot. The robobrew does have a perforated platform at the bottom that would support the grain bag off of the heating element. I think this would also allow the pump to operate properly to recirc. You’d probably want to insulate the sides of the pot really well though since the grain basket does help maintain temps inside the basket. I haven’t tried this myself although I do regularly use a bag inside the grain basket for normal batches.

 

[RePete]

You might be able to increase the grain volume by not using the basket, and instead use a BIAB bag inside the pot. The robobrew does have a perforated platform at the bottom that would support the grain bag off of the heating element. I think this would also allow the pump to operate properly to recirc. You’d probably want to insulate the sides of the pot really well though since the grain basket does help maintain temps inside the basket. I haven’t tried this myself although I do regularly use a bag inside the grain basket for normal batches.

You could do that. I bought the jacket with mine, which insulates the kettle. To me, a bag seems like it would be a pain to deal with, and I get along with the basket just fine.