Low Efficiency / low sparge temps

Argh, so last night was the second batch in a row where I fell short of my expected OG by 6 points and I need some help so my next batch goes better.

I brewed up Biermuncher's Centennial Blonde last week and hit an OG of 1.034 instead of 1.040. The mash itself went fine: I hit my target temp of 150 and only lost 1-2 degrees over 60 minutes. I mashed with 3 gallons of water for a ratio 1.35qt/1lb. The next couple of steps were probably mistakes. First, I mashed out with 1.5 gallons of 175 degree water, which only brought the mash to about 156 degrees. I vorlaufed and drained (batch sparging with a rectangular cooler and ss braid, btw). Then, I sparged with 3 gallons 175 degree water, which only brought the temp up to 160-162. So, I blamed the low efficiency on the fact that some sugars probably didnt dissolve.

So, last night when I brewed up Orfy' Hobgoblin clone, I wanted to make sure I brought the grain bed up to 170 or so. Again, I hit the correct mash temp and held it for 90 minutes. Then, I mashed out with 1.25 gallons boiling water, which the tastybrew calculator said would bring the mash up to 170. However, it only got up to 164. I vorlaufed and drained. Then sparged with 3 gallons of 180 degree water and the grain bed still never got above 166. My OG turned out to be 1.052 instead of 1.058.

Sorry for all the detail, but I wanted to lay it all out so maybe someone could help critique my technique. I use a 30 quart kettle, so I'm already pushing the limit of how much runoff I can collect (last night I actually collected about a gallon too much and had to add it about 30 minutes into the boil).

Any help would be appreciated. Also, as a side note, the Blonde has fermented down to 1.001, whats up with that?

Svudah,
Do you mill your grain or buy it milled? The most common reason for low efficiency is poorly milled grain. If you mill it yourself, mill it finer. If you buy it milled, request that your supplier send it through the mill twice. When I sparge, my mash temp. will usually only rise about 10f. over 45min sparge. I still get 85% efficiency. I don't think it is your sparge temp.
mark
Beer Diary...

Are you batch or fly sparging?

Batch sparging. The grind might be the issue, I mill grain using a lhbs's mill, but I've hit better numbers using their mill before (last time I brewed the Hobgoblin clone the OG actually overshot expectations).

But, what can I do to raise the grain temp to 170? How do some of you out there who batch sparge and collect around 6.5 gallons run things, i.e. how much water and what temps (ballpark, I know each brew is different).

First off what efficiency are you using to calculate your grain bill? As mentioned crush is the leading culprit for poor efficiency, sparge temp helps a little but more so in big beers where the sugar concentrations are much higher.

As for your blonde is your hydrometer calibrated and did you compensate for the temperature of your beer? If it is truly 1.001 I would be worried about contamination.

GT

I've been calculating for 65%. The beer was 61 degrees when I took a hydrometer sample, so I figure its pretty accurate +/- .002

svudah,

I was having the same problem, you really need 185 to 188 temp water to put into the 150ish mash to bring it up to near 170 for the batch sparge. I kept missing that temp too. Once I hit that, my efficiency went from mid to high 50% range up to 72%... You'll get there... its just the fun of maintaining those water temps before addition!