First AG BIAB

[freakish]

Hey folks,

I've read and re-read both step by step BIAB threads. Love them, great info. There's only one question i have, when using a kettle/pot to mash, is there any huge, 'omfg' effect if the temp drops from 152 down to 148 for a little while? (yes i'll be watching it but we all know things happen where you dont check it for 10+ minutes) As long as i get it back to 150 for a majority of the mash, things should be aok, right? I wont be using direct heat to bring up the temp, i'll be doing this on my electric stovetop, i'll use some of the sparge water and stir.

and fwiw, the recipe is something like this.. (3 gallon batch, mashing in 5 gal pot)

8.0lb 2-row (89%)
0.5lb Caramel 60 (6%)
0.5lb Carafa III Special (6%)

.75oz Columbus @ 60
.40oz Centennial @ 20
.90oz Centennial @ 5
1.25 oz Dry Hop for 10 days

6.7% abv (65% efficiency)
95 ibu's

7.5% abv (75% efficiency)
88 ibu's

I'm guessing i'll be in the range of efficiency i listed, so it'll be right where i'd like it (7ish% and 90ish ibu's)

 

[WhiteEagle1]

From what I've read on here.....not a big deal if your a couple degrees off on your target temp.....

 

[TopherM]

If you fall from 152 to 148 during your mash, you are going to lose a few points of efficiency/gravity and have a lighter bodied beer.

Will your kettle fit in your oven? Lots of stovetop guys will just set the oven for the mash temp and throw the kettle in there for the mash. BooYah, constant mash temp.

If you can't do that, find an old blanket, sleeping bag, or big towel and wrap the entire brew kettle up and keep it in your warmest room during the mash, paying special attention to a good insulating layer on the top where most of the heat escapes. You should be able to keep it within a degree or two with a good thick blanket.

If you can't do THAT, then you can either add a bit more of your base grain (an extra 3-5% or so should do it) or mash at closer to 156-158 to compensate for the efficiency loss.

 

[freakish]

Thanks for the quick replies, appreciate it!

No, my 5 gal pot is too tall for my oven. Measuring my oven was the first thing i did lol

I saw the towel method in one of the threads... i know its off heat but im not comfortable putting it on a hot-ass pot... then again, if plenty of people do it and nothing bad happens... i could take a stab at it. The pot i'll be using is 1mm thick, that should hold a decent amount of heat for 60 minutes, but obviously the more heat retained in the pot is always better.

Since its my first time, i think i'll try the blanket trick and stick with the 9 total lbs of grain and see what happens. Cant know without trying!

Thanks again, fellers.

 

[Doed]

I have used both an old sleeping bag and an old electric blanket to insulate my pot during mash. No problems. Plus I heat in the garage using propane, of course if I am going to add heat I remove the blanket first.

 

[RM-MN]

If your crush is fine enough most of your conversion will be done in 20 minutes or so. Your mash wouldn't have lost more than a couple degrees by then.

 

[wilserbrewer]

No, my 5 gal pot is too tall for my oven. Measuring my oven was the first thing i did lol

Did you remove the racks from the oven? I fit a 6 gallon pot in my oven filled w/ chili the other day. I removed one of the two racks and realized I could have fit an even larger pot had I needed to remove both racks??

 

[TopherM]

i know its off heat but im not comfortable putting it on a hot-ass pot

I use an old shipping blanket, and mine has a few scorch marks, but nothing major. Cotton isn't anywhere close to catching on fire at 155ish, but I wouldn't use a fuzzy blanket. Worst comes to worst, head down to Goodwill and get one.

FYI, just for my own knowledge (and now yours), I looked up the combustion point of cotton, and it's 842 degrees. Interestingly, the book Fahrenheit 451 is thus named because 451 degrees F is the combustion point of paper, a.k.a., books.

 

[tennesseean_87]

If you fall from 152 to 148 during your mash, you are going to lose a few points of efficiency/gravity and have a lighter bodied beer.

Why will lower mash temps cause a loss of efficiency? Will you routinely get higher efficiency when mashing higher? I know you'll get a lower final gravity my mashing lower, and thus a thinner beer, but why a lower efficiency?

 

[TopherM]

My bad....after further research, what I said was misleading. Mash temps affect enzyme activity, not efficiency. So efficiency is not affected, but fermentable sugars and body are.

 

[C-Rider]

Hey folks,

I've read and re-read both step by step BIAB threads. Love them, great info. There's only one question i have, when using a kettle/pot to mash, is there any huge, 'omfg' effect if the temp drops from 152 down to 148 for a little while? (yes i'll be watching it but we all know things happen where you dont check it for 10+ minutes) As long as i get it back to 150 for a majority of the mash, things should be aok, right? I wont be using direct heat to bring up the temp, i'll be doing this on my electric stovetop, i'll use some of the sparge water and stir.

and fwiw, the recipe is something like this.. (3 gallon batch, mashing in 5 gal pot)

8.0lb 2-row (89%)
0.5lb Caramel 60 (6%)
0.5lb Carafa III Special (6%)

.75oz Columbus @ 60
.40oz Centennial @ 20
.90oz Centennial @ 5
1.25 oz Dry Hop for 10 days

6.7% abv (65% efficiency)
95 ibu's

7.5% abv (75% efficiency)
88 ibu's

I'm guessing i'll be in the range of efficiency i listed, so it'll be right where i'd like it (7ish% and 90ish ibu's)

W/8 lbs of grain how much water did you squeeze into the 5 gallon pot? I did a BIAB w/6 lbs and could only get about 3.25 gallons of water into my cooler mashtun.

 

[borden]

W/8 lbs of grain how much water did you squeeze into the 5 gallon pot? I did a BIAB w/6 lbs and could only get about 3.25 gallons of water into my cooler mashtun.

I do up to 10 or 11 lbs with 3.25 gallons of water in a 5 gallon pot. Gets close to the top, but doesn't spill over. Though I do a dunk sparge (3.75 gallons) in a bigger, 7.5 gallon pot.

 

[Strangelove]

Every says how easy it is, but I can't hold mash temps doing BIAB despite blankets, old sleeping bag and bungee cords. I get to mash temps on my Bayou propane heater. I then mash and transfer the kettle to a glass top electric stove. Keeping the knob at 9 o'clock maintains the heat very nicely. This also allows me to give the mash a nice stir every 10-15 minutes. I take the kettle back to the propane to heat for mash out and for the boil. Easy, except that my new 15 gallon Blichmann Boilermaker takes 2 people to move safely (or semi-safely).

 

[C-Rider]

I do up to 10 or 11 lbs with 3.25 gallons of water in a 5 gallon pot. Gets close to the top, but doesn't spill over. Though I do a dunk sparge (3.75 gallons) in a bigger, 7.5 gallon pot.

I was worried about spill over. Next time I'll try w/more grain.

I mash in a 5 gallon cooler holds temp w/loss of only 1-2 * in an hour.

 

[borden]

I was worried about spill over. Next time I'll try w/more grain.

I mash in a 5 gallon cooler holds temp w/loss of only 1-2 * in an hour.

I sometimes refer to the "Can I mash it?" calculator if I'm getting to the higher end of the spectrum in terms of grain bill: http://www.rackers.org/calcs.shtml

From my experience, I can do up to about 4.3 gallons of volume without making a mess. So that's about 11 pounds at 1.25qt/lb.

 

[msa8967]

Looking to try a few smaller sized brews with the BIAB method on an electric stovetop. A buddy of mine also wants to try BIAB for the first time and I am wondering if 154 F is too hot for a nylon bag to be in contact with the bottom of the kettle during the mash? Could the bag be scorched at this temp while in contact with the bottom of the kettle?

 

[RM-MN]

If the bag is in contact with the bottom and you apply heat it certainly will scorch. I've done several 2 1/2 gallon BIAB batches on the stovetop and I bring my water to strike temperature, turn off the heat and stir the grain in as fast as I can, and put the cover on and wrap the whole thing in a bath towel, maybe even a kitchen towel added on the top and leave the whole thing covered for the hour. I usually only lose a couple degrees over the hour. If you open the cover during that time, expect about 2 degree drops each time.

 

[Number2]

I have heard that it can scorch the bag but I have never had it happen. I occasionally use low heat to raise the mash temp from my propane burner and I have not had a problem.

I will say that I am constantly stirring while applying heat so that I can see what the temp truly is at the thermometer. I am sure that helps to keep the bag from scorching.