First AG (BIAB) - way over gravity and lots of trub!

[grv]

Hey, so I decided to give BIAB a try today. :rockin: I used a Scottish 80 /- kit from Midwest. The grain bill was as follows:

11 lbs. American 2 row
.25 lbs. Biscuit
.5 lbs. Caramel 40L
.5 lbs Chocolate
.125 lbs. Special
.05 lbs Peated

For the kit, they list this as between 1.048 and 1.054 SG. The calculator on Brewer's Friend come out at 1.07 at 75% brewhouse efficiency, so that's a little weird.

Being BIAB, I would have expected my gravity to be less, but for the 6.5 gallons I sent to the brewpot, I had 1.064. My number into the fermenter after an hour and 15 mins boil was 1.075! I think (see about trub below) I ended up with about 5 gallons at the end, making me about 81% efficient according to Brewer's Friend, but dang, that's way off what the kit said to expect.

As far as crush, I set my gap at .03, which was a compromise between posts I read about small, .027 gaps that almost made four, and others who said that even with BIAB, a normal gap would do.

I did make some changes to the 60 minute mash they recommended. Due to the BIAB, I mashed for 90 minutes instead of 60. Temps were between 150 and 155 during this phase. Even with a blanket around the pot, it's cold here! I mashed the 12.5 lbs in 5 gallons of water, which was about all my 7.5 gallon pot could stand. At the end of 90 minutes, I raised temps to 165 as measured about 6" into the top of the mash after stirring. My pot is tall, and I was worried to go higher as I figured it's probably hotter down near the flame, even with the stirring I did at several points.

I lifted and drained the bag, putting it in a bottling bucket that had a small colander in the bottom. I put about 2.5 gallons of 175 degree water through the bucket, squeezing the bag at the end. Based on the final weight of the bag, I think I left around .75 gallons of liquid or so in there.

Anyway, the other thing is that unlike my extract batches, the cold break with my immersion chiller did not seem to drop all the crap to the bottom this time. There was a lot of it transferred to the fermenter, and it's slowly compacting. Not too worried about that, except that I can't really determine my efficiency very well due to not knowing how much liquid in my carboy is stuff that would have normally been left in the pot as opposed to "real" wort.

So I am left with that big SG. There's about a half ounce of challenger (full boil) and an ounce of fuggles (30 minutes) in there. With the SG, not sure that is enough.

What should I do? Yeast is pitched, but I could go back to the really old days of partial boil extract, and dump a gallon or so of water in there to reduce the gravity to the range the kit indicated. I could do nothing... Ideas?

Thanks!!

 

[grv]

forgot to mention - gravities were taken at 60 F.

 

[GetStrunk]

I'd either boil and cool some water and add that to bring the gravity down, or leave it alone and call it a wee heavy

 

[grv]

Given where I ended up, it seems like I am just about on target for a wee heavy... maybe I'll just say I meant to do that!

Still wondering what the heck happened though. Seems like the grain bill may be a little heavier than some other 80 recipes I looked at. Maybe they're expecting you to use a rolling pin to crush this stuff or something? Oh well!

 

[inhousebrew]

IMO that's an awfully big and overly complicated Scottish 80. My 80 recipe is three grains and 8.5 pounds to clock in at 4.1% ABV. If you have room in the fermenter I would add some water to thin it out. I'd be a tad concerned about the balance of the hops and malt especially if you mashed around 155* at times. Or you could ride it out and see what happens. Either way, enjoy!

 

[acidrain]

Not sure why the kit instructions were so far off.
BIAB efficiencies are usually in the 80% range. Not sure why you thought you needed to mash for so long.
Seams like your numbers are right on to me (grain bill and expected gravity).
Next time, use Irish moss at 15 minutes too help drop the break material.
Yeah, at the end of your boil, if the gravity is way higher than expected for the style, I would thin it down a little.

 

[grv]

IMO that's an awfully big and overly complicated Scottish 80. My 80 recipe is three grains and 8.5 pounds to clock in at 4.1% ABV. If you have room in the fermenter I would add some water to thin it out. I'd be a tad concerned about the balance of the hops and malt especially if you mashed around 155* at times. Or you could ride it out and see what happens. Either way, enjoy!

Yeah, looking at some other recipes for this style, I came to realize that this one was a bit odd! I thought that getting a kit, I was going easy on myself, but clearly that wasn't the case. Also gotta get a better handle on mash temperature control in the winter months if I am going to do BIAB. Maybe more blankets or something.

Not sure why the kit instructions were so far off.
BIAB efficiencies are usually in the 80% range. Not sure why you thought you needed to mash for so long.
Seams like your numbers are right on to me (grain bill and expected gravity).
Next time, use Irish moss at 15 minutes too help drop the break material.
Yeah, at the end of your boil, if the gravity is way higher than expected for the style, I would thin it down a little.

As far as the mash times, I think I just read too much A lot of BIAB threads talk about a longer mash to make up for what would otherwise be lower efficiency. My efficiency was pretty good, but maybe next time I should test with some iodine at 60 minutes, and mash out then if everything is done? I did use Whirlfloc in the last 15 minutes, as I have done with my extract brews, but it only seemed to coagulate the undesirables. They did not settle to the bottom during chilling as they normally do. And there is a lot of it! It is slowly compacting in the fermenter, but there is twice that of an extract brew.

Anyway, thanks for you help and suggestions. I will add some water. If I factor out all the extra trub and call what I have in the fermenter 4.5 gallons, this calculator says that if I was at 1.075 and want to hit say, 1.052, I should add almost 2 gallons of water. Not sure I can fit that, but I will get at least a gallon in there.

http://merrycuss.com/calc/gravityadjustmentwater.html

Thanks again

 

[grv]

Trub situation pic. Top line is the level right after transfer to fermenter. Picture was taken about 17 hours later.



Uploaded with ImageShack.us

 

[RM-MN]

Yeah, looking at some other recipes for this style, I came to realize that this one was a bit odd! I thought that getting a kit, I was going easy on myself, but clearly that wasn't the case. Also gotta get a better handle on mash temperature control in the winter months if I am going to do BIAB. Maybe more blankets or something.



As far as the mash times, I think I just read too much A lot of BIAB threads talk about a longer mash to make up for what would otherwise be lower efficiency. My efficiency was pretty good, but maybe next time I should test with some iodine at 60 minutes, and mash out then if everything is done? I did use Whirlfloc in the last 15 minutes, as I have done with my extract brews, but it only seemed to coagulate the undesirables. They did not settle to the bottom during chilling as they normally do. And there is a lot of it! It is slowly compacting in the fermenter, but there is twice that of an extract brew.

Anyway, thanks for you help and suggestions. I will add some water. If I factor out all the extra trub and call what I have in the fermenter 4.5 gallons, this calculator says that if I was at 1.075 and want to hit say, 1.052, I should add almost 2 gallons of water. Not sure I can fit that, but I will get at least a gallon in there.

http://merrycuss.com/calc/gravityadjustmentwater.html

Thanks again

Try the iodine test at about 20 minutes. If your crush/grind is really good (which helps you get great efficiency) your conversion may be done by then or soon after. since you are BIAB, your grains aren't sitting in the wort so you really don't have to do a mashout. Just fire up the burner when you pull the bag of grains out and your wort will be at mashout quickly.

The kit maker was probably planning on 50% efficiency and you got about 80%. Now you know to plan on better efficiency so you can adjust the recipe to take that into account.

 

[newnick]

This is a good calculator for BIAB. http://www.simplebiabcalculator.com/

Last weekend I did the same kit on my second BIAB batch.
I mashed at 152 for 60 min. in 7 gals. of water.
Raised the temp to 165 for 10 min.
Drained the basket and bag over the pot, rinsed the grain with 1 gal. of ambient temp water, moved the basket and bag over a smaller pot and squeezed out as much as I could.
Boiled for 60 min. (recipe calls for 90 min.)
Put about 5.5 gals. in the fermentor with about a quart left in the pot.
SG was 1.0536 after compensating for the 70 degree temp.

The recipe is for a 5 gal. batch and I ended with about 5.5 gals.
If I would have done a 90 min. boil the calculator would have suggested more water to start with.

 

[maltoftheearth]

GRV -- you will get some, but not much, additional conversion from mashing for over an hour.

I have had the same problems as you, last year I swung back to the other side of things (was having problems undershooting my SG.) You're in a good place if all you have to do is dilute to get the SG you want!

 

[grv]

Thanks all! I'm sure I'll get this dialed in a little closer on the next one.