Questions about my mash process

So I got my first all grain in this past Tuesday and I'd say it went really well. I was only 1°F off on my numbers and my efficiency according to tastybrew.com's calculator was 69.2%. I'm definitely pleased with that for my first time but I would like to get it a consistent 70-75%. It also seems I some how left some sweet wort in the tun. So I'll just post what I did and see what you all say. Also, if it helps I'm using a 10 gal mash tun with a copper manifold I made and was collecting 6.5 gal to get 5.5 gal post boil.

Kolsch
10 lb German Pils 2 Row
8 oz CaraPils
1 lb White Wheat
Wyeast 2565

I brought the strike water to 172°F and added 4.3 gal of it to my tun. I let it drop to 170°F and then added my grains stirring them in slowly. Although I don't think I had any dough balls, next time I think I'll try to slow it down even more. After some stirring it hit 152°F so I called it good and shut the tun. I stirred it 3 times during the mash. Looking back I probably should have just left it after the first stir in, but I've read that some people stir it occasionally during the mash. (opinions?) At the end of the 60 min mash the temp had dropped to 150°F due to the stirring. I vorlaufed 3 times to get the wort clear. I started with the valve a quarter of the way open and then half way through I opened it to about three quarters of the way. I only collected 2.9 gal and I know some of this is due to grain absorption, but I'm wondering if I would have left the valve open only a quarter of the way if it would have effected how much was collected.

Next I brought my sparge water to 183°F and added 3.8 gal of it to the mash. It stabilized at 167° which is only a degree lower than what the recipe called for. I stirred it in and let it sit for 10 mins then began vorlaufing. I collected 3.5 gal from the sparge which seems a little low. Since the grains were already saturated I was expecting next to no loss. Again I'm wondering if the draining speed had an effect. The runnings that I collected from the mash were 1.070 and 1.033 from the sparge, both at 77°F. The sparge SG seems high.

Thanks for taking the time to read this. Any insight you can give me or improvements you see I can make would be greatly appreciated. I definitely want to improve my process as much as I can.

Your technique seems perfect. I wouldn't change much, if anything, but here are a few thoughts.

I assume you were batch sparging- if that's the case, no need to go slow with batch sparging. You don't have to let it sit for 10 minutes, either.

You really can't stir too much, but you don't need to stir the mash at all unless you're getting "cold spots". What I do is stir when I mash in, and stir, stir, stir, stir. Then check the temperature in several spots- if it's different, stir some more. Look for doughballs and thick areas. Once the mash is fluid throughout and the temperature is the same throughout, you can cover it and walk away. There is no need to do any gentle stirring- stir like you mean it!

After the mash, vorlaufing and draining is done at full speed but it sounds like you did just fine with that. "Losing" a gallon of water to absorption in that size grainbill in the mash is just about the same as I do. You shouldn't lose any in the sparge, but maybe you mismeasured, or you had some deadspace. Do you have some tubing on the ball valve to drain the MLT? Sometimes that sucks out more wort than with no tubing.

My only suggestion is that you may have left some sugar in the grain as the SG reading after the sparge does seem high. I would have done a second sparge. Of course, you are limited by your BK size as well. 69% is not all that bad. We have gone to a HERMS system and our efficiency improved. We always added 1/4 pound extra 2 row to a 5 gal batch for our lower efficiency but now we just have to add water to get the final SG correct. We plan on brewing about 16 gal batched but normally end up with 17 gal now. (That slightly effects the HBU but in my mind, not enough to worry about, as we make good beer!)

Yooper, I did use some silicone tubing. Next time I'll just open up the valve and let it flow. I was kind of concerned that I would get a stuck sparge, but I guess that is a smaller chance than I thought. When I did my "dry" run with no grains I only had 2 cups of water left in my tun. I'm not sure if having grains in there would effect the dead space.Oak, I'll try a splitting my sparge water in two next time and see if that helps any. Thanks for the advice.