You don't need to go to a smaller set up. I've been using the same size cooler for my 5 gallon batches and they come out just fine.
I may have missed it in the thread but are you using a copper manifold or SS braid in your mash tun? If not what are you using.
Do you collect the wort in the same vessel you boil your extract brews in?
What do you use to get it from your cooler to your boiling vessel. Its got to be something in these few steps prior to boiling, as long as the steps for all grain and extract are the same once it hits the boiling vessel.
BTW I batch sparge, have never had a problem, and don't have to check the Ph.
I have a SS braid... Brass fitting from Home depot...
I have a Silicone Hose (
http://www.austinhomebrew.com/product_info.php?cPath=178_59_549&products_id=10014 ) that I use to get the beer from the Mash Tun to the my Boil pot (which is the same one that I use for Extract).....
I agree that it has to be in the first steps before boil. Here is a quick overview of how I have been brewing...
1. Heat 1.25 qt of water per lb of grain to 175 degree.
2. Put water in Mash tun and close for 15 minutes.
3. add the grains (I have a mill, but 3 out 5 batches I ordered pre milled) to the mash tun and stir until I get to 154ish
4. close my Mash tun. Open it every 15 min to take temp reading (has been holding the temp really good usually drop only 1 or 2 degress in 60 minutes)
5. At 45 minutes I heat my Sparge water to 175 degrees (I use Beer Smith and it usually tells me to add about 3.5 - 4.5 gallon to sparge, but my yield have been closer to 5.25 gals, but this is probably cause I don't have Beersmith calibrated for my boil off)
6. at 60 mins...I run off my first runnings. I have a 2 qt pitcher that I do my run off into... I am usually doing about 4 qt before I put the hose into the kettle.
7. After I am done running off, I dump in my Sparge water... stir... and close the lid for 15 mins....
8. Run off my sparge running same proceedure of about 4 qts before I stop getting particles it in and it looks fairly clear...
9. Run it into my kettle... Been ending up with about 6.5 gallon (which is a little high I think that it needs to be closer to 6 or 6.25 for my boil off..
10. Do a 60 minute boil... (basically from here is the same as my extract) and add hops per recipe..
11. 5 minutes left in boil I put in my chiller.... and it takes me about 10 or 15 (tops) to chill to about 75 or 80....
12. Take my pot inside... I have a spout on it... and run it through a mesh strainer (it does work great to help aerate).... (obvisouly my strainer, funnel, carboy, hoses for spout, etc... are or have been in sanitizer for at least 30 minutes...
11. I shake my bottle after I pitch the yeast... put my airlock or blow off on... store at 65 to 70 degrees... and it does its thing...
Anything jump out at you in this... any questions to clarify my procedures?