Okay, so I managed to brew my first all-grain batch today. I encountered a few (normal) first time glitches and I'm curious about something. I couldn't take a gravity reading after the first running, but took one as I was transferring the wort (1st and 2nd runnings-batch sparge) from my fermentation bucket to the boiling kettle. I started with 7 gallons of water and got about 5.5 gallons of wort into the boiling pot with a measured gravity of 1030. I took the reading about 1.5 gallons into the transfer. I had a hose come off, resulting in some loss of wort. So the grain absorption and loss from the hose problem was about 1.5 gallons. Went through the boil, ran the wort through a counterflow chiller and wound up with about 4.25 gallons of finished wort. When I took the gravity reading, the reading was 1050. Would the roughly 20% boil off explain the increase in gravity? I know I need to increase my initial water temp by at least 10 degrees, from 170 to 180. I was shooting for a mash temp of 155 and missed it by 5 degrees. I missed my target batch size by .75 gallons or so - I'll assume that I lost maybe a quart on the hose, but that would still leave me about 2 quarts short. How much water do you usually use for a 5 gallon batch? How long do you let the batch sparge water sit on the grain bed before draining? I let it sit for 10 minutes today.

Additional info:
1) Mash temperature was 150 degrees at the beginning and 148 at the end of the hour. (4 Gallons)
2) Recipe called for 11#s of grain (2-row, honey and crystal 40L).

I appreciate any and all feedback. Thanks! Uli

for a grain bill that size probly around 9-10 gals. i lose about 27%/hr in my boiling rig, and usually let the sparge sit 15-20 with a stir or 2 and a 2 -5 min sit before runoff

Uli,

You might want to check out John Palmer's "How to Brew" for a good description of all-grain brewing and the required calculations. There's an online version that's free. But, here are some answers that might help:

Boiling 5.5 gal wort at 1.030 down to 4.25 gal would increase your gravity to 1.0388. You can calculate this as follows: 5.5 * 30 / 4.25 = 38.8. Not sure why your gravity seemed to increase more. Are you correcting your gravity measurements for temperature? Are you sure all of our volume measurements are calibrated?

As for volume loss, I usually assume the grains absorb 0.12 gal per lb. You'll also lose some volume to your mash tun's dead space. For me, it's another 0.35 - 0.4 gal.

I usually try to collect 0.5 to 0.6 gal wort per lb grain from my mash, depending on how big a beer I'm doing and how long I'm willing to boil. Collecting more will increase your efficiency, but could require a long boil to get back down to 5 gal.

I don't let the second batch sparge sit for any more than a few minutes...usually just long enough to stir. Not sure if letting it sit longer might increase extraction...seems like it might, but I haven't bothered.

Thanks Paul! I used the Joy of Homebrewing and The Homebrewer's Bible, as well as online resources to prepare for this batch. I will admit to just taking the plunge, without doing too many calculations. I figured this was experimental anyway, trying to figure out what the boil off rate is going to be and how much mash tun dead loss to expect. I really wonder what happened with that gravity reading. I mean, I'm happy that I wound up with 1050. I now have some numbers to use with my system, but that @#$#@$#@ hose disconnect caused me to miss the dead space calculation.

Uli, that sounds like a pretty good brew day, especially for your first attempt. I wasn't thinking at all about gravity readings and that stuff my first time in. Didn't know about batch sparging back then, so that takes a lot of work out of it. Congrats in the success.

Congrats, Uli. Now, start thinking about your next batch.

Paul - looking back at my notes, you are correct, I had a brain cramp. I DID NOT correct for the temperature. So, the 1030 was actually 1046, once I corrected for the temp. That was one of those things that slipped my mind in middle of the process. I bet if I add that boil off now, it'll get close to the 1050.

Dk and BB - thanks for the words of encouragement. Let's see how this batch pans out, but gotta admit, I'm already thinking about the next batch. I'm a process design engineer by trade and having an 'uncontrolled' process drives me nuts. Personality flaw....must understand what is happening at every step along the way. Looks like I grossly underestimated the amount of water needed. Do you typically batch parge more than once to get all the sugars out of the grains?

Thanks for the help! The collective knowledge on this board and the quick answers make Tastybrew an awesome resource.

Well, you passed the first hurdle... (getting started on AG) now it's just a matter of practice.
148 - 150 is still within range
I say good job dude!!

Uli, congratulations. I'd like to echo something that Paul touched on. It took me three head-scratching batches before I thought to double check something I had taken for granted -- that all of the equipment I was using was accurate. Turns out that the actual volume of a pitcher I was using was at least 15% off from factory markings. Really messed with my calculations and results.

Uli,

If you're an engineer, you'll probably have the process nailed in no time.

I usually calculate my boil off during each brew. I plan for a 90 minute boil and estimate the boil off during the first 20 minutes. Then I decide how much boil off I'll get between my 60-min hop addition and the end of boil (allowing for kettle losses and shrinkage...not the George Costanza shrinkage!). That tells me the volume at which I should add my 60 minute hops.

I think most who batch sparge do two sparges...meaning you drain the original mash water, then refill and drain. If you want to collect more wort, you can add to the original mash water after the mash is complete, and use a bigger second sparge volume. But I've never had to do a third sparge. I suppose if you were trying to do a really big beer in a small mash tun you might need to do a third sparge.

I wouldn't worry about leaving some sugars behind. You don't actually want to oversparge or you can get some off flavors. You should stop sparging when the gravity drops to 1.008 - 1.010 (corrected for temp). I think you also want to make sure the pH is in range. These really aren't things to worry about unless you're fly sparging or batch sparging with a lot of water.