Help With Stovetop Ag Biab Please

[donburke]

OK, i have done 2 half batches of AG BIAB, 1st one has been tasted and is fantastic, although a little on the sweet side, probably from a high mash temp, so i am now focusing a little more on accuracy.

i will be brewing an over gravity wort and then diluting with water for fermentation

if someone can answer the following, it would be greatly appreciated.

1) wanting to mash 4kg of grain (grain at 22 degrees), mash temperature of 66 degrees, i calculate my strike temperature to be 72.1 degrees, does this sound right ?

2) i am doing this on an electric stove, and will turn off the hotplate when putting in the grain in, is the temperature likely to rise as the pot is still on the hotplate, even though switched off ?

3) I am increasing my bittering hops by about 20% to allow for the decrease in utilisation because of the over gravity wort, wort will be around double the gravity, does 20% sound like enough compensation ?

thanks

 

[apd]

1) Sounds ok but given you've got the option of direct heating your mash tun, I wouldn't worry about being too accurate.

2) Yes, I would think so. When you're getting close to strike temp, turn off and let the temp stabilise, THEN add your grains. And continue stirring for 5-10 minutes to make sure temp stabilises where you want it for the mash. OR, could you take the pot off the hotplate?

3) Depends on the gravity I think. Have a look at How To Brew (howtobrew.com). I think Palmer has calcs for that sort of thing.

Andrew

 

[mxd]

1) start with a couple of liters less then add hot or cold to adjust

2) depends on the element, but it may

3) you can do this in beer smith, set it up via equipment, then it will give you precise amounts, but the 20% might be a little high ?

 

[donburke]

thanks for the replies,

i guess i have to be flexible

might do a trial run of just water and see what happens after 10 minutes still on the turned off hotplate

 

[jbowers]

That's a very good idea.

 

[stm]

1) Have a look at this calculator:

http://www.grainandgrape.com.au/articles_o..._StrikeTemp.htm

2) Can you just move the pot to a cold hotplate or a cork mat on the bench as soon as you hit the strike temp?

3) Simple IBU calculator here, so you play around with the boil gravity to see how it affects bitterness for a given amount of hops (if you don't have beersmith):

http://www.brewheads.com/ibucalculator.php

 

[argon]

1) start with a couple of liters less then add hot or cold to adjust

2) depends on the element, but it may

3) you can do this in beer smith, set it up via equipment, then it will give you precise amounts, but the 20% might be a little high ?

+2 for setting up via beersmith best tool you can have for high og post top up brews. Plus it'll do all you calcs for other stuff for you too!!

 

[Nick JD]

Over a lot of stovetop brews, I've found that when I turn the element off at 69C water temperature my initial (there's always a loos this way - but it doesn't matter too much) mash temperature will be 71.5C due to the residual heat left in the electric element acting on the mash.

So I factor in 1.5C after "element off".

However - next time you are mashing or paddling or chopsticking your grain around before the lid goes on and the insulation goes on top - leave your thermometer in during this period (being careful not to paddle it) and you'll notice a slight drop in temperature here too.

It's a balancing game. Weighing up how long you like to stir and paddle against your strike temperature and the overall loss in your "tun".

My heat loss over an hour is often 3C. So if I want 67C, I'll aim for 68 (losing 1C pissing about with the grain) and end on sixty something. Not exact, but close enough for the Blues.

But this all resta on your thermometer's accuracy. If you live at sea level, bring a saucepan of water up to the boil and put your thermometer in it. Check it reads 100 (don't rest it on the metal though).

EDIT: if you want a less sweet, thinner beer 67C is quite high still. Maybe aim for 63C. Almost all of the sugaz are converted in the initial 15 minutes of the mash - so a 3C loss is no problem at all. I've done a few 30 minutes mashes with negligible losses in efficiency, but the rule is - the lower your mash temp the longer you need to mash for. If you're in a hurry, a 20 minute mash at 70C is all you need. But you'll have a beer you can eat with a spoon. YUM!

So: don't piss about between adding your grain and insulating your mash tun because your initial mash temperature is the most important thing ... not the temperature of the mash after 15 minutes - that's almost irrelevant

 

[Bribie G]

Over a lot of stovetop brews, I've found that when I turn the element off at 69C water temperature my initial (there's always a loos this way - but it doesn't matter too much) mash temperature will be 71.5C due to the residual heat left in the electric element acting on the mash.

So I factor in 1.5C after "element off".

However - next time you are mashing or paddling or chopsticking your grain around before the lid goes on and the insulation goes on top - leave your thermometer in during this period (being careful not to paddle it) and you'll notice a slight drop in temperature here too.

It's a balancing game. Weighing up how long you like to stir and paddle against your strike temperature and the overall loss in your "tun".

My heat loss over an hour is often 3C. So if I want 67C, I'll aim for 68 (losing 1C pissing about with the grain) and end on sixty something. Not exact, but close enough for the Blues.

But this all resta on your thermometer's accuracy. If you live at sea level, bring a saucepan of water up to the boil and put your thermometer in it. Check it reads 100 (don't rest it on the metal though).

EDIT: if you want a less sweet, thinner beer 67C is quite high still. Maybe aim for 63C. Almost all of the sugaz are converted in the initial 15 minutes of the mash - so a 3C loss is no problem at all. I've done a few 30 minutes mashes with negligible losses in efficiency, but the rule is - the lower your mash temp the longer you need to mash for. If you're in a hurry, a 20 minute mash at 70C is all you need. But you'll have a beer you can eat with a spoon. YUM!

So: don't piss about between adding your grain and insulating your mash tun because your initial mash temperature is the most important thing ... not the temperature of the mash after 15 minutes - that's almost irrelevant

Yes, even using a 40 L urn, the process of doughing in, stirring and then insulating with a sleeping bag and doonah is a scene of frantic activity followed by an hour and a half of doing nothing. Sometimes I even go out shopping, and don't get back till the 2 hour mark. As Nick says, after the first twenty minutes or so a couple of degrees drop is not going to make a huge difference. That's the thing I've never 'got' about HERMS, why they go to all that huge expense and worry - although I suppose it does give them control to the Nth degree, if that's what turns you on. :icon_cheers:

 

[Nick JD]

Yes, even using a 40 L urn, the process of doughing in, stirring and then insulating with a sleeping bag and doonah is a scene of frantic activity followed by an hour and a half of doing nothing. Sometimes I even go out shopping, and don't get back till the 2 hour mark. As Nick says, after the first twenty minutes or so a couple of degrees drop is not going to make a huge difference. That's the thing I've never 'got' about HERMS, why they go to all that huge expense and worry - although I suppose it does give them control to the Nth degree, if that's what turns you on. :icon_cheers:

Here's an interesting table:

Mashing period 15 30 60 120 180

60 C
Extract (%) 50.2 53.4 57.2 60.7 62.2
Ferm ext(%) 36.0 39.0 43.1 47.9 50.2
65 C
Extract (%) 60.6 62.2 62.8 63.6 63.6
Ferm ext(%) 44.2 46.6 48.5 50.7 51.7
70 C
Extract (%) 61.2 62.5 62.9 63.4 63.6
Ferm ex(%) 40.9 42.0 41.6 42.2 42.7

As you can see, a "warmer" mash of say 69C will gain less than 1% sugaz after 15 minutes.

This completely changes my views on mashing. I can just add another hundred grams of malt and whip the bag out at 15 minutes.

Something to try next brew.

 

[donburke]

Over a lot of stovetop brews, I've found that when I turn the element off at 69C water temperature my initial (there's always a loos this way - but it doesn't matter too much) mash temperature will be 71.5C due to the residual heat left in the electric element acting on the mash.

So I factor in 1.5C after "element off".

However - next time you are mashing or paddling or chopsticking your grain around before the lid goes on and the insulation goes on top - leave your thermometer in during this period (being careful not to paddle it) and you'll notice a slight drop in temperature here too.

It's a balancing game. Weighing up how long you like to stir and paddle against your strike temperature and the overall loss in your "tun".

My heat loss over an hour is often 3C. So if I want 67C, I'll aim for 68 (losing 1C pissing about with the grain) and end on sixty something. Not exact, but close enough for the Blues.

But this all resta on your thermometer's accuracy. If you live at sea level, bring a saucepan of water up to the boil and put your thermometer in it. Check it reads 100 (don't rest it on the metal though).

EDIT: if you want a less sweet, thinner beer 67C is quite high still. Maybe aim for 63C. Almost all of the sugaz are converted in the initial 15 minutes of the mash - so a 3C loss is no problem at all. I've done a few 30 minutes mashes with negligible losses in efficiency, but the rule is - the lower your mash temp the longer you need to mash for. If you're in a hurry, a 20 minute mash at 70C is all you need. But you'll have a beer you can eat with a spoon. YUM!

So: don't piss about between adding your grain and insulating your mash tun because your initial mash temperature is the most important thing ... not the temperature of the mash after 15 minutes - that's almost irrelevant

spot on, the heat keeps rising after switching hotplate off, i found out today

i caught the strke temp on the way back down, and hit my mash temp exactly !!

strirred every few minutes in the first 20 minutes, ended having to fire up the hotplate on low heat for a few minutes to get me back up 1/2 degree that it dropped !!

i was aiming for 20 litres of 1.046 but ended up with only 17 litres of 1.044, hopefully the higher boil gravity underutilised the hops also so my bittering is on par

thanks for the replies

 

[RdeVjun]

Interesting data Nick, where's that from?

[Begin idle speculation]
If my interpretation is correct (highly unlikely), what it does suggest to me is that for consistency in drier beers (which is what I am targeting with TTL- inspired ESBs), it is perhaps better to aim low at the 'rain in' and then top up with hot water to the target mash temperature rather than aim high and add cold water as things seem to happen pretty quickly at strike water temps by the looks. This might explain the unpredictable nature of some of my TTL- style beers which I usually mash around 65C.

It might also explain the hyperattenuation I've been getting at these temps (excuse the mouse in the screenshot ...).
BribieG, I suspect HERMS may enable some consistency, a gradual increase up to targets rather than an abrupt occasional slightly- overshot step which is what I get with my pillowcase. As we've all probably wondered, and a few have measured, no matter what the setup, just how homogenous is the mash? Patchy mash/ overshoots would explain the occasional not- so- dry one I get, ingredients aside of course.
[/End idle speculation]

I guess that to a point Nick, adding that extra bit of grain might not account for low brewhouse efficiency, at least as I understand it...

My 2c... :icon_cheers:

 

[Nick JD]

Interesting data Nick, where's that from?

Brewing Science and Practice.

Do you think that attenuation may be more to do with your yeast than your sugar profile?

EDIT: I'd like to see what happens between 0 and 15 minutes in a mash. Does the stuff just go BANG! Sugaz? Seems to.

Listen to us stovetop brewers compensating for lack of equipment...

 

[bum]

So fermentable sugar is the only thing we want to be extracted in a mash? You can buy it in bags at the supermarket if that's all you're after.

 

[RdeVjun]

1469? Not the world's most attenuative strain (67- 71%, reportedly), but a good point nevertheless. I've been using it exclusively for some time now and with lower- temp mashes (<66C) I've been getting consistent hyperattenuation.

Yep, lots seems to happen in the first few minutes, that's why the data intrigues me. I'll try for the lower strike temp and a top up, with what little room there is in a 19L stockpot! :icon_cheers:

Edit: BTW thanks for the data!

 

[Nick JD]

spot on, the heat keeps rising after switching hotplate off, i found out today

i caught the strke temp on the way back down, and hit my mash temp exactly !!

strirred every few minutes in the first 20 minutes, ended having to fire up the hotplate on low heat for a few minutes to get me back up 1/2 degree that it dropped !!

i was aiming for 20 litres of 1.046 but ended up with only 17 litres of 1.044, hopefully the higher boil gravity underutilised the hops also so my bittering is on par

thanks for the replies

Nice one. A lot of this is just getting to know your gear.

At what efficiency did you calculate your 20L of 1.046? Stovetop brewing is not the best for efficiency, but we make up for in money spent on shiny equipment and that makes the pigeons in my back yard happier for all the sugaz in their fat bellies.

 

[Nick JD]

So fermentable sugar is the only thing we want to be extracted in a mash? You can buy it in bags at the supermarket if that's all you're after.

Take a closer look at the table I posted above, Bum.

 

[bum]

I can just add another hundred grams of malt and whip the bag out at 15 minutes.

This is what I'm commenting on. Your suggestion is that an extremely high percentage of what we want from malted barley is done in 15 minutes and, by extension, the other minimum of 45 minutes is a waste of time where nothing useful occurs. Don't you think that if this were the case someone would have noticed this before you?

 

[donburke]

Nice one. A lot of this is just getting to know your gear.

At what efficiency did you calculate your 20L of 1.046? Stovetop brewing is not the best for efficiency, but we make up for in money spent on shiny equipment and that makes the pigeons in my back yard happier for all the sugaz in their fat bellies.

my recipe was a scaled down version of tony's LCBA, i.e. 20 / 52 X grain .... 20 /52 x hops

i adjusted the first hop addition only, i used double the scaled down amount, i downloaded beersmith and plugged the hops additions in

i calculated that if i was boiling only 12 litres of 1.070 wort, then to keep the IBU on par i had to double the first addition

i mashed approx 4kg of grain in 10 litres for an hour then strained the bag, then soaked the bag in another 6 litres of 78degree water for 10 mins then strained the bag and poured the runnings into the pot, boiled and added hops

from the 16 litres, looks like i lost approx 8 litres to what the grain kept, evaporated and cold break left in the pot

after chilling the remaining 8 litres i added 9 litres totalling 17 litres and measure 1.044 at around 20 degrees

i decided to not add any more water, so pitched my yeast

 

[Nick JD]

This is what I'm commenting on. Your suggestion is that an extremely high percentage of what we want from malted barley is done in 15 minutes and, by extension, the other minimum of 45 minutes is a waste of time where nothing useful occurs. Don't you think that if this were the case someone would have noticed this before you?

Okay, lets make it simple for bum...

70 C
Extract (%) 61.2 62.5 62.9 63.4 63.6
Ferm ex(%) 40.9 42.0 41.6 42.2 42.7

At 15 minutes into the mash 61% of the grain has been turned into sugaz, 41% of this is fermentable (ie. not more than four glucoses stuck together).

At 60 minutes into the mash (still with me?) 63% of the grain has been converted to sugaz, 42% of it fermentable.

I'm not sure how much simpler I can make it. And yes - most people don't understand what they are doing when they brew beer. I didn't understand mashing until a few days ago when I bothered to read about it.

Will my beer be any better? Probably not.

Did someone else notice this before me? Of course - but you didn't. So I'm slightly less dumb than you.