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-   -   First All Grain + BIAB (http://www.homebrewtalk.com/f36/first-all-grain-biab-192349/)

ne0t0ky0 08-23-2010 09:23 PM

First All Grain + BIAB
 
Did my first AG BIAB this past weekend (only my second brew) wanted to share the experience and I've got a few questions at the end. Here are the details:

AHS Oaked Porter (11lbs), 5 gallon batch
9.5# 2-row
.75# Crystal 90
.5# Chocolate Malt
.25# Black Patent
1oz Brewer's Gold
1oz Willamette
1 300ml starter made from White Labs British Ale Yeast (#5)

I've got a 8G pot and sewed up a nice poly bag for the pot. I used Beersmith to calculate the tun volume needed for the recipe, and it just barely fit into the pot. I ended up with 2.4 quarts per lb. Heated 6.6gal of water to 165, added in the grains (crushed twice by LHBS), asst. stirred while I added the grain. Finished stirring and checked temp, 156, which was pretty close to the 155 I was shooting for. I wrapped the pot in bubble foil wrap and covered with towels. Check at 20 minutes (stirred) and was at 154, by 50 minutes, was down to 151, so I added some heat, and after 60 minutes, pushed temp up to 165 to mash-out. I tied up the bag, hung from a hook over pot and squeezed the bag for all I was worth collecting 5.75 gallons. pre-boil gravity was 1.054 after temp adjustment. Recipe said it should've been 1.048 pre-boil. Added some water to raise to 6.7 gallons for the boil, didn't bother to recheck gravity after water addition since it was higher.

Boiled for 60 minutes with hop schedule Brewers at the start, .5 oz Will at 45 minutes in, and .5 for last 5 minutes. After heat was off, but before I chilled, volume of kettle was 5.5 gallons with hot wort. Gravity was 1.068 adjusted for temp, target was 1.057. Chilled wort down to 75 degrees. After chilling, I measured volume again and noticed I now had 4.5 gallons. I added water to raise to 5.5, mixed and remeasured gravity, now at 1.055! (target was 1.057). And if I've figured Beersmith efficiency tool out, my brewhouse efficiency was 74%, not too shabby for a first time AG+BIAB. I transferred to my 6.5gall carboy and put into ferm chamber set at 64 and waited till the temp strip on the side read 72 degrees and pitched after some vigorous shaking of carboy and yeast. Fermentation started with in 3 hours and was going really well by 12 hours later.


Here are my questions:

I usually see posts about boiling 6.5 gallons and a ~1gall/hr boil-off rate, which I thought I had observed, but after cooling the wort (and I know heat does raise volume some amount, don't recall the value now) I had almost a full gallon less of volume. Do you think I really boiled off 2 gallons? or was my initial 6.7 gallons after the mash less than that because the temp was about 170? If so, how does one adjust the volume versus temp?

I used mrmalty.com to calc the starter size, but I'm a little confused about the size. I inputed 5.25 gallons of 1.057 wort with intermittent shaking and it gave me back 1.25L of starter. Is that volume of yeast slurry before pouring off the beer on top? I started with 3 cups (710ml) of water and 3 oz of Light DME (per my LHBS 1 liter starter instructions). After doing the boil and cool and pitch of the yeast into the flask, I had about 550 ml of liquid. Once I poured off about half of the beer on brew day and mixed it up, it was 300ml of yeast slurry. For the 1.25L of yeast from mrmalty, is that the volume into which you pitch the yeast? or is that the post fermentation volume of yeast I should have afterwards ?

BillyBroas 08-24-2010 06:01 PM

I had some trouble following your process, so I'm going to jump right into your questions. Let me know if you want clarification from there.

1. You could have boiled off 2 gallons. You said this is your second brew? It takes a few to figure it out, but it depends on a few factors. Here in Denver where it's low humidity I boil off around 1.75 gal/hr. Heat does raise the volume, but I don't have a formula for it and at the temperatures where I take my readings it really doesn't affect it much.

2. The volume on mr malty is the volume of wort after boiling. So for 1.25L, you will want to put slightly more than 1.25L into the pot, boil down to 1.25L, then pitch your yeast into that. You won't have 1.25L of yeast slurry.

ne0t0ky0 08-24-2010 06:24 PM

Quote:

Originally Posted by BillyBroas (Post 2235417)
I had some trouble following your process, so I'm going to jump right into your questions. Let me know if you want clarification from there.

Uh oh. If I can clear that up, let me know. It probably doesn't matter for this post, but I may have other questions and I definitely want to make sure I clearly communicate my brewing process.

Quote:

Originally Posted by BillyBroas (Post 2235417)
1. You could have boiled off 2 gallons. You said this is your second brew? It takes a few to figure it out, but it depends on a few factors. Here in Denver where it's low humidity I boil off around 1.75 gal/hr. Heat does raise the volume, but I don't have a formula for it and at the temperatures where I take my readings it really doesn't affect it much.

Ok, I'll be sure to keep an eye on it next time. It's going to take a few brews with the same process before I can capture that variable accurately. And since I'm getting close to OG with dilution afterwards, I think I can handle being low on volume as long as my efficiency is high enough.

Quote:

Originally Posted by BillyBroas (Post 2235417)
2. The volume on mr malty is the volume of wort after boiling. So for 1.25L, you will want to put slightly more than 1.25L into the pot, boil down to 1.25L, then pitch your yeast into that. You won't have 1.25L of yeast slurry.

Ah, that makes more sense. The volume is the amount of wort needed for the yeast to properly multiply. That clears it up. I shouldn't be surprised; I've always heard that starters are mini-batches, so the process should be the same, ie, more volume than needed to *target* a final volume of X. the mr.malty volume is the batch target into which you pitch yeast. Thanks for clearing that up.

BillyBroas 08-25-2010 07:36 PM

It's cool it seemed like the info wasn't critical to the questions you were asking. It takes many brews to really learn your system. And then you go and change something and you have to calibrate it all over again. My grain bill always has funny numbers because I factor in things like deadspace losses and evaporation rate.

Also remember that you can make adjustments on the fly. If you're efficiency tanks and your preboil gravity comes out low for example, you could always add malt extract to give it a boost. Like wise if it comes out high, you can dilute with water.

homebrewdon 08-26-2010 02:54 AM

Unfortunately I think you might have ruined your setup, you better give all of your beer stuff to your brother just to be safe, also the wort chillers.:ban:


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