HERMS and sparging

[Jeltz]

If you have a HERMS system is there a need to sparge if you can fit all your brewing liquor in the MT?

My thinking is that while a looser grist ratio will produce a slightly dryer beer BIAB does it without significant problems. By recirculating the wort you are in effect rinsing the grain and you could mash out at say 77°C at the end.

Is that viable or am I barking up entirely the wrong tree???

 

[adomant]

Don't know of anyone who does this, I think it will play havoc with the the mash bed and enzyme activity. There is a recommended grain to liquor ratio for a reason, not sure exactly why but you might end up finding out the hard way.

 

[adomant]

Oh I remember now, the weight of the water will compact the mash and it will get stuck - don't do it!

 

[Jeltz]

I've read an interesting article on grist ratios and as I said it has a tendency to produce a more fermentable beer and the theory suggests that once you get above a 4X ratio you risk enzyme stability. However in practice BIAB does this all the time and does achieve saccharification.

If its just a question of water weight and stuck mashes a counterflow system like a Braumeister could be employed.

 

[adomant]

The braumaster is an interesting concept since it is effectively a rims in reverse in that it flows up through the mash bed. I have been wondering how to achieve that in a standard mash tun with herms and the pump the other way. The issue I feel is picking up the flow from the top. Maybe a mash pipe effect with a "false top", interesting..,

 

[Jeltz]

Indeed, you either have to have an internal grain container or an over flow tube running down to below a false bottom, the later would be slightly easier to achieve.

 

[Fil]

full volume mashing is something ive considered, and to maintain the mash consistency you can employ a number of tricks,

first raise the tun FB high so a large volume sits below it,

OR employ a 2nd insulated vessel as a large volume underback to hold the excess liquor.

OR consider using an insulated kettle as a BIG volume rims heater under pid control.

 

[PD]

I'd like ro know something similar re herms.
The process of sparging as I understand it is to wash all the converted sugars out of the grains.
So if we have a large enough mash tun that can hold say all the water required for the brew, could we not just continually recirculate water at the correct temperature through the grains until all the sugars are in solution and flowing around with the water until its drained off to the kettle ?

I've never done herms so I might be talking tosh and if so I apologise.

 

[Jeltz]

I think that's exactly what I am asking, PD!!!! :mrgreen:

 

[pittsy]

I have herms and you would still be better to sparge after mashing either by fly or batch . Your grains will be coated in the sugar solution and so sparging just gets that extra bit that would of been missed . I still don't get why fly sparge though , after i have mashed as normal it takes 5 mins to drain , 2 min to re fill , 10 mins rest and 5 mins to drain and that's it . While fly sparging takes an hour ish , i get great efficiency too.

 

[adomant]

another thought is that with the water volume so high, would the concentration of enzymes be high enough to effectively convert the sugars, I can imagine those little enzyme fellas swimming around going "hey, where are my friends, where's all the grain?" (sorry that if that thought lacks technical microbiological description).

I guess the tradition has been to treat them as 2 separate processes, conversion and sparging for some reason or other.

I think an experiment is in order to see if it really does make any difference, I recall from my BIAB days that I would use 15/20 litres for 5kg of grain but we would be talking something more significant here.

 

[adomant]

I still don't get why fly sparge though

Fly sparging does get you more efficiency but this is not so important at the homebrew level. some prefer to fly as they feel it better ensures the grain / filter bed integrity which might be important for some styles, whereas batch sparging disrupts the filter bed to some extent I guess.

 

[oldjiver]

I always mash in my IGLOO tun at 3kg malt to 15litres of liquor. I do it to nearly fill the tun for thermal efficiency. I have never had a problem with conversion. I use a mash bag with a coarse bottom and have never had a stuck mash. I cant follow the "weight of water" theory as if its covered its floating?

 

[adomant]

I always mash in my IGLOO tun at 3kg malt to 15litres of liquor. I do it to nearly fill the tun for thermal efficiency. I have never had a problem with conversion. I use a mash bag with a coarse bottom and have never had a stuck mash. I cant follow the "weight of water" theory as if its covered its floating?

it normally floats in a simple infusion but when you turn on herms you are removing the water from underneath and flowing back on top which will weigh it down. As for conversion, a ratio of 5/1 should be ok but as has been mentioned earlier it is more than ideal - how much does this impact efficiency ? not sure, would need to do a comparison.

 

[brewtim]

I sparge with a small volume in the Braumeister 2-3 litres (and I think most BMers do) just to rinse remaining sugar from the grains in the malt pipe, this appears to get a couple more sugar points. I mash with ~34 litres and an average 5Kg grain, this is a 7L/Kg grain ratio which is way outside the 'recommended' and have had no problems with conversion with my stepped mashes (I've not heard about problems from other BMers or BIABers either).

I'm not sure where the 'recommended' water to grain ratio comes from, maybe its based on traditional brewing practice rather than chemistry and has become a modern myth, with modern brewing systems, modified malts, water treatments etc things have been changing for a while now (in homebrewing at least).

Re full volume with HERMS - I think Fil has hit the nail with his post. An underletting method might work also, but you would need some way of keeping the grain from rising with the water, the BM uses a heavy filter plate, the BM also has one (or two in the case of the 50L) powerful pump pumping directly under the mash tube providing enough flow to run through the mash, I'm not sure if you would have enough direct force with a tun with a false bottom and bends in the pipework, worth a try though

 

[theboytony]

Interesting ideas, I've often wondered where the ratio comes from. Might be worth seeing if aleman would mind popping his head in and explaining it for us

 

[adomant]

The article posted by Jeltz (3rd from top) explains it in a way I can understand, so it must be simple