Efficiency Discussion and Question

Hi all -
New to the Beersmith forums... I have seen a few questions on here regarding brew efficiency and thought I would provide some information on what I have learned so far - although keep in mind I am a newbie to all grain brewing - only my 9th batch so far. 
First, I use a very basic setup for my brewing - I have one 9 gallon brew pot and 2 coolers (one 10 gallon round igloo cooler for mash tun and one 48 quart cooler for hot liquid tank). 

First lesson learned was not to use a Stainless steel hose (plumbing line) as the mash tun filter/false bottom.  Pay the money and get a real false bottom for your cooler - especially if you are fly sparging.

Second and most important if you are fly sparging you will need to use very hot water if you are not mashing out.  I have found that I need 185-190 degree water to fly sparge with to get the grain in the mash tun up to temp (168-170)  I found that when I used this very hot water my effeciency increased dramatically - 10-15%.  Also, keep in mind that if you are using a cooler like me for a hot liquid tank you will lose a lot of heat when adding your hot liquid to the cooler.  I found that using my 48 quart cooler that I would lose nearly 15 degrees in temp when transferring the hot water from the boil pot to the cooler.  So boiling water at 212 degrees in the pot would quickly turn into 190 degree water in the cooler.  I think this is probably one of the single biggest lessons learned so far for me and was not something I saw or read a lot about before brewing.  Keep in mind my initial fear was getting the mash too hot and having issues with tannins etc... but keep in mind if you have 150-154 degree mash it will take quite a bit of hot water to get that grain bed to 168...

Now for my question --  I recently brewed a Double IPA that had about a 16-17 lb grain bill.  What I found was that when fly sparging I noticed that with my thermometer about mid way into the grain that it was not getting up to the 168 degree temp.  I am wondering if with larger grain bills if I would be better off just performing a batch sparge to ensure getting the mash up to temp (168) vs. fly sparging so that the sugars get into the wort.  My efficiency wasn't terrible as I got to 73% but it wasn't my normal 76-80% that I have been seeing lately.  I am just wondering with larger grain bills if fly sparging may not be the best alternative vs batch spargin??  Any thoughts or lessons learned in this area??? 

Thanks --- Joe

I have a suggestion that will make things a lot easier for both regular grain bills and for large grain bills.  It will also allow you to use the same method for any size grain bill.  Instead of heating your hot liquor tank to boiling and letting it settle at 190F before going into your mash tun to fly sparge, you can try the following.

Heat your sparge water to 185F and put it into your 48 quart cooler/HLT, so that it settles at 170F.
Then recirculate your mash by slowly pulling off about a gallon and pouring it back on top of your mash to get it to run clear.
Once it is running clear, pull out most of the wort from your mash and bring it up to about 200F.
Once it is at about 200F, put it back into your mash tun and stir well to get the temperature stabilized at about 170F.
You can then recirculate it until it is running clear, then start your fly sparge.
Both your mash tun and HLT will be at about 170F, providing you with the best efficiency that you can hope for.  You'll also be at 170F throughout the entire mash!

I hope this helps.  I do this for batch sparging and found that I get my best efficiency by heating my wort up to get to mash out temperatures.  It should work even better for fly sparging!