RIMS and sparging

[dharalson]

I have been brewing for about 6 years and after a several year sabbatical I've brewed 8 batches this year with 6 all grain and the last 3 have been on my RIMS.  The RIMS is working well and I have been able to hold temperature in the mash and mashout.  My question is: should I continue to recirculate the sweet wort while I am sparging.  I have a drain tap on the outlet side of the heater that drains into the kettle.  I set this to drain about 2-3 cups per minute to get a 30-45 minute sparge and I continue to recirculate until the top of the grain bed is uncovered.

I have been debating with myself (I have won yet :-) as to whether makes since or not.  My first thought in doing this was to maintain the sparge temperature, but I am concerned that I am not washing the sugars out well if I keep putting sweet wort on top.

Thoughts?

David

PS:  Why isn't sparge in the dictionary on a brewing forum?

[scaryeyes]

I have been thinkin about this too. I only used my rims-like equipment once, and that time all was catastrophic with a stuck sparge immediatly.

[Troutguy]

I brewed professionally for about 4 years in the 90's.  The proceedure that we used for lautering was as follows:

Mash out to 168-170F.
For Homebrewing mix the mash very well right at the end of mash-out.
Let the mash rest in tun for 15 min before begining vorluaf (recirc).
Begin vorlauf and continue until desired wort clarity is reached.
Cease vorlauf and begin first kettle runnings - take first wort gravity reading.
Begin sparge with 168-170F liquor when bed is approx 1/2" below surface of wort in lauter tun.
Regulate hot liquor sparge to maintain this approx liquid depth over grain bed.
Rake into bed approx 1/2 depth gentally and occationally (if applicable...many homebrewers omit raking)
Take gravity readings at approx every 4qts of wort to kettle.
Stop sparging when you are approaching you desired pre-boil gravity.  (approx .010 SG or 5-10 plato away from target)
Keep draining wort to kettle until kettle wort achieves desired pre-boil gravity.
Dip Kettle for Volume and record Volume and gravity for start of boil.

So in essence, I'm saying that once i start my sparge, I do not vorlauf any further.

Does this help?

T-

[dharalson]

T
Thanks for the reply.  I've changed something in the process just about every time I've brewed.  I am try to stabilize the process and work on consistency.  The last couple of brews I continued to circulate during the sparge.  In the after action review, I started wondering about all that sugar rich wort I was dumping back on top of the grain bed.  Your answer has convinced me that I should not do that. 

Again, thanks

David

[beercheer4me]

What about circulating mash to keep correct temperature in the mash second? Should a second running of the mash for 10 gallon brew then sparge the last 3-4 gallons? Tks

Or what would be the correct way to lauder10 gallons

[dharalson]

I brewed this weekend and here's my take

I am brewing 5+ gallons with 3.5 gallons in the mash (10.5 lbs at 1.25q/# rounded up) and 4.5 gallons in the sparge.
After mashing at 151 deg I ramped up the temperature to 168 deg continuing to recirculate.  After reaching 168 deg I stopped the recirculation and started the sparge.  The final SG of the runnings was about 1.008 - 1.010.  I got an OG in the fermenter of 1.058 with 10.5 lb grain and 5.38 gal for an efficiency of about 80% :-)  (best yet)

Comments on recirculation while sparging.  The idea of the sparge is to wash the sugars off of the grain.  If you continue to put high sugar content wort on top of the grain bed it will be counter productive.  Sort of like trying to clean with dirty water.  If you need to maintain temperature in the HLT then that water should run through the heater in a separate circuit.  The other option would be to batch sparge and recirculate each batch to clear and maintain temperature.  I will try that in the future to see how that works.

Hope this helps, David

[CR]

Answer your  own question by doing it both ways and observing the color and taste of the wort extracted.
I think you'll feel comfortable with the result.