B I A B Step Mash

[Ginger NZ]

Has anyone here done a step mash using BIAB?

I had a chat with another prospective BIABer and he mentioned that he was interested in brewing lagers. I've watched a few youtube clips on the theory behind step and decoction mashes and I can't think of any reason why it wouldn't be possible to strike and then rest, then raise the temp to mashing temps.

So, can anyone bring the science and tell me why it's a bad idea? Any gotchas that they've encountered

 

[phonos]

I've done a step mash on a bohemian lager - 50 degrees for 20 mins then 66C for 60mins. There was issues with the water chemistry which lead to a hazy beer (I get this with all my pale beers due to alkaline water). Apart from the appearance, the beer turned out great. Just ensure your bag isn't on the base of the pot when you raise the temperature.

 

[seemax]

You could also do a step mash via multiple water additions. For example, start with a 2.5L/kg ratio for the initial 50C rest, followed by another addition to get to 66C. It does slightly defeat the purpose of BIAB in that it's not a full volume, one pot deal, but... my bag sits on the bottom of the pot and it's easier to add hot water than to heat it up on stove.

 

[PistolPatch]

Have done a few of these Ginger.

It's a very easy process with a skyhook, rope and the paint stirrer type mash paddle.

When raising the temp, put your paddle in the bag and then lift the bag high enough so it is not touching the bottom. When you reach the desired step temp, lower the bag again and just give the stirrer a little jiggle up and down to make sure the mash is of even temp.

Monitor your temp and if you need to add more heat, just raise the bag.

This method of leaving the paddle in the bag is handy for those who like to step up to 72 and/or 78 as well.

Cheers,
Pat

 

[RobB]

You could also do a step mash via multiple water additions. For example, start with a 2.5L/kg ratio for the initial 50C rest, followed by another addition to get to 66C. It does slightly defeat the purpose of BIAB in that it's not a full volume, one pot deal, but... my bag sits on the bottom of the pot and it's easier to add hot water than to heat it up on stove.

I've done this and it worked a treat. I have an urn at home but it only takes 8 litres. However, if I use it three times and calculate my volumes correctly, I get protein and saccharification rests followed by mash-out. Saves gas too!

 

[Hashie]

I step mash all my brews.

Generally start at 54 for 15 minutes then step up to 65 for 60 minutes followed by mashout at 77 for 20 minutes.
I don't bother lifting the bag, I just use the paint stirrer/mash paddle thingy to keep everything agitated while the flame is on.
Never had a problem doing this.

 

[Thirsty Boy]

and if you want to play the decoction game - BiaB makes it easier (sort of)

You gather up the bag from one edge only and it slowly raises the whole grainbed up to the top of the pot - then its really easy to scoop out the "solid" portion of the mash which is what you want in your decoction vessel anyway.

But... you have to add heat to the main brew via your burner as well - the greater mash volume means that the decocted portion wont raise the temps by nearly as much as in a traditional mash.

Play with the brewing software and it isn't too hard to crunch the numbers and hit your temps - but life is too short for frequent decoctions - they are an occasional pleasure for when I am feeling particularly masochistic.

TB

 

[sumo]

I'm the other brewer Ginger is talking about, we had a good discussion about BIAB the other day, and I am looking forward to giving it a good try.

After reading the BIAB thread I have just got to the point where I have a vessel big enough to take a full volume, and a burner to run it. One last thing to buy is the rack for the bottom so the grain bag has about 50 - 100mm clearence from the bottom of the keggle.

 

[Thirsty Boy]

There is some debate about whether that rack is needed or not..... if you are careful when adding heat, lots of people are getting away with no rack at all.

Oh - and on teh step mashing front. With the large volume being heated, the steps are more like long gentle ramps. I would be very inclined to trade some of my "rest" time in exchange for some of the ramp time.

so as an example instead of

56 for 10min
step to 66
66 for 60 min

I would be thinking

56 for 5min
ramp to 66 over 15min
66 for 50min

and maybe even consider increasing any sach rest temps by one or two - because the mash spends a reasonable amount of times at teh lower sach temps on teh way up.

Its going to be a case of start at a traditional step regime - and tweak from there.

TB

 

[Hashie]

I see what you are saying thirsty, but I think a lot depends on the set up.

For me, it is only a 5 - 7 minute "ramp". I have no problem stirring the mash for a few minutes while the temp comes up to the next rest.

Nor do I use a rack to protect the bag. I find the bag floats while heating to the first rest temp (this is where I add the grain). Subsequent heat additions simply require the grain bed being stirred/agitated to keep it off the bottom and therefore protected from direct heat.

 

[sumo]

I was going to do a dry run this weekend before committing grain to the pot, however I may as well put the gumboots on and jump in because if I read any more I am liable to became an expert of the theory and never have touched completed a BIAB.

I anticipated my first run as follows:

My receipe: (Munich Helles)

Ingredients
4.50 kg Pale Malt (Weyermann)
0.15 kg Munich Malt (9.0 SRM)
20 gm Tettnang [4.50%] (60 min) Hops 12.5 IBU
15 gm Hallertauer, New Zealand [8.50%] (15 min) Hops 8.8 IBU
15 gm Tettnang [4.50%] (5 min) Hops 1.2 IBU
1 Pkgs Danish Lager (Wyeast Labs #2042) Yeast-Lager


- hit 57-58 using 30 litre (expecting 5 - 7 litre loss) boil then add 4.65kg grain (@ about 20) I should get 55.
- hold 5 - 10 min, then raise to 66 over 5 - 10 min (ever the optimist!).
- hold @ 66 for 50 - 60min (depending on time to rest and ramp.)
- raise to 77 for 20 min mash out.

- 60 min boil with above hop schedule

- no chill (as immersion chiller not ready yet)

Well I'll be off to my local craft brewer for my grains (and a beer) and hopefully have a brew day early next week .

Thanks for the information guys, I'll try to remember either to take photos or video.

 

[Damian44]

I hope it all goes well for you sumo. Im planning my first AG very soon too. What size and shape pot do you have? Arn't you suppose to start with 38 liters of water. Thats a loss of 15 litres. I have a 80 litre stock pot thats very wide. Im planning on starting with 40 liters and leaving the lid half on.

 

[Thirsty Boy]

I see what you are saying thirsty, but I think a lot depends on the set up.

For me, it is only a 5 - 7 minute "ramp". I have no problem stirring the mash for a few minutes while the temp comes up to the next rest.

Nor do I use a rack to protect the bag. I find the bag floats while heating to the first rest temp (this is where I add the grain). Subsequent heat additions simply require the grain bed being stirred/agitated to keep it off the bottom and therefore protected from direct heat.

Yeah, thats why I was sort of trying to state it as a range rather than a "you should shorten your rests by this much..."

So it'd definitely depend on how fast you can get heat into the system. Very much longer than your 5-7mins though and I'd be starting to think about shortening rest times and adjust rest temperatures. Even at say ten minutes to get from 56-66 thats 5ish minutes in the commonly recognised sachrification zone, but at the really low end of it, and when yo consider how many posts I've seen saying that conversion is virtually completed in 15-20mins... thats to 25-33% of your most effective conversion time spent at lower temps than you intend with a given rest temperature.

Anyway, it all sorts itself out in the wash once you've done a few brews, tasted the results and fed them back into your process - definitely an "experience" rather than a "theory" thing... just something to consider thats all.

TB

 

[Ginger NZ]

Thanks for the replies. I'm hoping to get going with this at the weekend.

 

[Thirsty Boy]

I was going to do a dry run this weekend before committing grain to the pot, however I may as well put the gumboots on and jump in because if I read any more I am liable to became an expert of the theory and never have touched completed a BIAB.

I anticipated my first run as follows:

My receipe: (Munich Helles)

Ingredients
4.50 kg Pale Malt (Weyermann)
0.15 kg Munich Malt (9.0 SRM)
20 gm Tettnang [4.50%] (60 min) Hops 12.5 IBU
15 gm Hallertauer, New Zealand [8.50%] (15 min) Hops 8.8 IBU
15 gm Tettnang [4.50%] (5 min) Hops 1.2 IBU
1 Pkgs Danish Lager (Wyeast Labs #2042) Yeast-Lager


- hit 57-58 using 30 litre (expecting 5 - 7 litre loss) boil then add 4.65kg grain (@ about 20) I should get 55.
- hold 5 - 10 min, then raise to 66 over 5 - 10 min (ever the optimist!).
- hold @ 66 for 50 - 60min (depending on time to rest and ramp.)
- raise to 77 for 20 min mash out.

- 60 min boil with above hop schedule

- no chill (as immersion chiller not ready yet)

Well I'll be off to my local craft brewer for my grains (and a beer) and hopefully have a brew day early next week .

Thanks for the information guys, I'll try to remember either to take photos or video.

Its my opinion that you don't need to leave the mash at Mash/out temps for the 20mins - in BiaB the Mash out really isn't for the same reasons a mash out is for in a traditional system. Its really not a mash out at all, its just raising the whole mash to sparge temperatures before you conduct your lauter - to increase the solubility of the sugars and decrease the viscosity of the liquid a little. Basically it means that your "lautering" step, ie pulling out the bag, is happening at the right temperature. No mash out and you are trying to lauter 10 cooler than everyone else in the brewing world does.

You have no need for the traditional mashout rest, because thats all about stabilising fermentability during a long lauter - and your lauter takes a couple of minutes not a couple of hours.

So when I BiaB - I bring the mash up to 78C, then pull the bag immediately, half the time I don't even turn the burner off - just get the grain out of the pot and let it continue on its merry way to the boil while I am buggering about with the bag.

You might as well cut the 15-20mins out of your brew day and spend a little more time drinking instead of brewing

Thirsty

 

[sumo]

I hope it all goes well for you sumo. Im planning my first AG very soon too. What size and shape pot do you have? Arn't you suppose to start with 38 liters of water. Thats a loss of 15 litres. I have a 80 litre stock pot thats very wide. Im planning on starting with 40 liters and leaving the lid half on.

Hi Damian

I have a converted 50 litre keg. From what I have read of the theory in BIAB it says you lose about .75 litres of water to grain absorption and and 15% per hour to boil. So I believe I'll lose about 5 - 7 litres being optimistic. I only need 19 - 20 litres for the keg, so this run will give me a good indication of the volume needed in the future.

You might as well cut the 15-20mins out of your brew day and spend a little more time drinking instead of brewing

Thirsty

I like your style... it's a done deal!

 

[reviled]

Good to see 2 kiwis getting into BIAB on the same weekend B) Best of luck guys!

 

[sumo]

Good to see 2 kiwis getting into BIAB on the same weekend B) Best of luck guys!

I'm blaming you for this.... my wife will not be happy with you.

 

[reviled]

I'm blaming you for this.... my wife will not be happy with you.

:lol: lol, I can handle that :lol: Its worth it...

Is this James P?

 

[sumo]

:lol: lol, I can handle that :lol: Its worth it...

Is this James P?

That's me! Ginger is Rusty.