Originally Posted by neomantra
Quick question. For us batch or double batch spargers, it seems the common convention is to not perform a mash out to allow more water for sparging.
How would you recommend raising and stabilizing sparge temp for us?
The meat and potatoes of the primer is hitting your desired rest temp for a single infusion mash. It gets a little hazy once you get to the sparge step because that process is very system dependent....but I'll take a shot.
Look at this question in two parts.
1) Mash-out and Recirc
Mash-out and Recirc
I know the mash-out is technically there to quickly raise the grainbed above 170F, and denature the enzymes in the mash; essentially, locking in the fermentability of the wort. In truth, I don't know if that gallon (or in some cases, less than a gallon) of boiling water I add prior to recirc is enough to get me to 170F. Rather, I look at the "mash-out" as one last opportunity to liquify my mash as much as possible, and to get the wort to a temperature more capable of dissolving sugars into solution - whatever that temperature may be. As I said before, don't sweat specifics of the mash-out.
However, in my experiences, the mash-out and the recirc go hand in hand, and one would be borderline useless without the other. Obviously, the process does not need to be automated with a pump, and reviewing your question, is also independent of the upcoming fly/batch sparge. Even if I were to batch sparge, I would still follow my advice as given and add about a gallon (if it fits) of boiling water to my mash about 10 minutes before I want to begin my sparge. I would give the mash a good stir to incorporate the boiling water, and then begin a varlouf (or as I say, "recirc"). My recirc is automated, but slow. Over 10 minutes, I would be surprised if I recirculated more than 2 gallons. Recirculating 2 gallons can easily be done manually. Up to this point, there is no difference between your system and mine, so that mash-out + recirc process should be familar.
I appreciate your concern about "If I mash-out, I have less water to sparge", but in my opinion, that is exactly what you want to do. Again, this is only opinion, because I do not batch sparge. Look at it this way, you are essentially moving that gallon from the last bit of wort collected to the first bit of wort collected. In my mind, the first runnings trump your last runnings. This plays to the logic of no sparge brewing from a wort quality standpoint, but in this case, you give yourself a little help in the efficiency department by doing that second (or third) batch sparge. To be honest, I don't really understand the concern about maintaining
sparge temps, because if you follow the infuse, recirc, drain method I just laid out, each upcoming "batch" sparge you do after first runnings is like its own mini-mash-out (you just don't need the water to be boiling because the grain you are adding the sparge water to is "dry"). So to take a guess, you would only have to heat the sparge water to 180F or so, infuse, stir to incorporate, recirc, and drain - and do that as often as you need to reach the designed preboil volume. Maintaining temperature should be a non issue, because you are controlling what is going into the tun for each sparge step, and you know better than me what temp that water needs to be. Temps only need to be maintained long enough for you to run your recirc and get the tun drained.
So in summary, if I were to batch sparge, I would still do a mash-out. I think you would want to collect as much of your pre-boil volume from first runnings as possible, because those first runnings are going to hold the highest quality wort. Additionally, the mash-out will aid in dissolving the sugars back into the solution you are about to drain, and the now slightly thinner mash will make recirculation easier.
This process may change the efficiency you have become used to, but I really think the wort quality will be better. To me, that is the name of the game.