A Guide To All-grain Brewing In A Bag

[The King of Spain]

PM - here is a link to a published paper that supports your observation


Comparasion of brewing methods

 

[Kai]

From the theory that Dr K is preaching, the worts should be dextrinous. ie in thin mashes the alpha amylase will perform at a normal rate, but beta amylase will be retarded, thus leaving longer sugar chains that the yeast can't ferment, thus leaving sweeter, underattenuated beers. From what people are posting, this doesn't seem to be actually happening.

I thought that was it. I dislike referring to underattenuated beers as sweet, since sweetness perception also depends on grist composition and hopping levels. But I digress.

 

[Finite]

Just some more info guys.

My first BIAB and AG has been fermenting for about 4 and a half days now with a safale US-56 dried yeast which I reydrated as the instructions of their website. It has just slowed down now. Fermentation temp was around 20C

Stats for the brew so far are:

Efficiency into kettle: 70%
OG: 1.042
FG: 1.011
Attenuation: 73%

I expect this to drop maybe another point soon so will probably hit 75% on the button, I will let you all know where she stops.

Notes: Smells great and doesnt taste overly sweet at all however is reasonably hopped at 40 IBU which may mask the sweetness a little

 

[Chris]

6.2kg grain 30L at 1052.

Maxt

Well bugger me.
not bad at all.
Maybe you guys could some how incorporate a small fruit press to get the last little bit out like coopers do. lol

Cheers

 

[The King of Spain]

Lads, dough in with a "traditional" liquor/grist ratio of about 2.5L/Kg then mash for an hour, then add the rest of the water. Will give the beta amylase time to work in a sensible liquor:grist ratio then the additional water will allow you to soak out a little extra sugar

.

Will let you all know how PoMo's advise works. I used two boilers and added 13L at 70C to boiler with the grain in it. I had to give it some flame for a few minutes to get it to exactly 66C (try doing that with an esky).

All said a very simple interum step.

 

[PostModern]

I had to give it some flame for a few minutes to get it to exactly 66C (try doing that with an esky).

Immersion element I was a few degrees off strike temp today due to not pre-heating my tun (oops, boiled the kettle, made a cuppa, forgot to empty kettle into tun to pre-heat like I normally do).

Let us know how it turns out, though you're not strictly one-pot brewing now, are you?

 

[The King of Spain]

Let us know how it turns out, though you're not strictly one-pot brewing now, are you?

Nope, whatever works. Good beer is the outcome, will take shortest route.

OK, OG is 1.0045 into 23L
I may be supprised if Nottingham yeast does not pull the FG below 1.008 because thats where the last 2 ended with a full volume (BIAB) mash. Thats one serious yeast. Now the little beasties can chop into the tail ends of the c-tree (so theory goes) so lets see.

By way PoMo- thanks. No extra work so may owe you a beer(s). Had a smaller kettle from my 1 extract day.

 

[PistolPatch]

Merry Xmas Guys!

Just found a computer and will have to do a few other things before I write back anything of substance here. Have a fairly good idea of what has been happening here and it's great to see that there are enough knowledgable guys out there to reply to somewhat foolish posts. Donya guys!

Haven't had time to see how all the above started but for now we can all be confident that BIAB beers seem to be no different from any other beers. I, in some ways, am the least responsible poster here but, looking back, I can't see any claim I have made that is not at least now a fact or possibility.

Stick by your guns guys. BIAB is absolutely fine. It has already proved itself right.

What I'm interested in now is finding out where it is wrong. This would be of value and I'm sure there are some areas of real value where BIAB will fail. But let's do triangular tests first eh?

Looking forward to reading the above posts more fully when I have time but am already really pleased to have seen what I have seen

Donya,
Pat

 

[Finite]

Update on my brew.

Been in primary for 6 days now:

OG 1042
SG 1010

Apparent Attenuation: 75.4%

 

[The King of Spain]

Has anyone else done the Ross's Schwartzbier that came with PPs documentation. I had an OG of 1.0045 (23L). Its just about out of steam after 4 days using Nottingham yeast. Gravity is currently 1.0011 and cant see it getting much lower.

This was using a more conventional mash in volume of 13L with rest added at 60min.

Interested to see how finishing gravities compare with others

EDIT Note

Sorry folks

Calabrating for temperature the true OG was 1047 and FG (now 2/1/07) of 1010

 

[Finite]

Update on my brew.

Been in primary for 10 days now and its droped another 2 points.

OG 1042
SG 1008

Apparent Attenuation: 80.3%

 

[Finite]

Brewing my 2nd AG now. A Choc oatmeal stout. Its mashing atm ill let you know how I go.

 

[Finite]

Porter chilling in a jerry now. Efficiency was worse this time 66.1%.

I didnt end up mashing at a lower liquor to grain ratio as the stove I was going to heat the extra water in was being used. I also think I could have poored and mixed the grains a bit slower when I added them. The spent grains I tasted still had some sweetness. This also was a bigger batch @ 23L (35L strike water). And I probably mashed a little hot 66.7 - 64.5

Next brew I do im (really) planing to mash at a 2.5L liqour to grain ratio and heating the extra water on ther stove.

I was thinking I could lift the bag up and tie it off to strain over the pot and rinse the grain bag with the hot water im adding, what do people think about this?

 

[FNQ Bunyip]

HI finite , on my last one I removed the bag at the end of the mash and sat it in a 20lt stockpot then poured 3lts of warm water from a pot over the grains and lifted the bag to drain for about 15mins and got 3.4lts of 4.6brix wort out and added to the boil that was the rest of the brew. I dont know if it made any real differance to the end result but I feel better about it as the grain was rinced., and wasent as sweet as past batches.. can allways boil for a few extra mins to get back to right volume..

:beer:

 

[Finite]

Wow this US-56 is really efficient. 12 days in the primary now and heres the stats of the summer ale.

OG 1042
SG 1005

Apparent Attenuation: 87.7%

 

[The King of Spain]

Schwartzbier bottled today, 'tis very very good . As previously posted I did a very simple interum step using two boilers and a conventional mash volume of about 13L for first 60min...etc

Now thing is I can't see why I would want to change my current process (from 2 boiler brewing that is) . I can very quickly change my mash temp and if desired I can do a mash-out, though a stuck sparge is the least of my probs. And rather than rinse water through grain, I move grain in a bag though water and (least I think) get same result. Check the posted gravities, same OG but lower FG (OK used Notts which has better attenuation than US56)

Lets call it simply brewing

 

[Finite]

Just tried my first AG after being in bottle for 3 days.....I know but I couldnt wait. (Ross's Nelson Sauvin Summer Ale)

A little undercarbonated as expected but other than that... Smells amazing! The aroma of these hops just totaly kicks arse, wonderfull white wine and fruity aroma. Tastes great! A smooth malt profile up front followed by a crips wonderfull hop bitterness which shifts to the back of the palate and leaves a really nice dry and appleskin-like aftertaste with moderate bittnerness. Full body but so easy to drink..I drank this in the time it took me to write this post. Cant wait to try her after 2-3 weeks...if it lasts

This one is actually a little similar to knappstein.

Very nice!

Its all over, im hooked, condemed to brew AG and drink quality beer for the rest of my life. :chug: +1 to the list cause im never going back.

P.S: Apparent Attenuation finnished at 90.1%

 

[phonos]

From the theory that Dr K is preaching, the worts should be dextrinous. ie in thin mashes the alpha amylase will perform at a normal rate, but beta amylase will be retarded, thus leaving longer sugar chains that the yeast can't ferment, thus leaving sweeter, underattenuated beers. From what people are posting, this doesn't seem to be actually happening.

I don't know if its safe to bring this up again :unsure: , but I was reading this article which mentions that a "Thin mash dilutes concentration of enzymes slowing conversion, but leads to a more fermentable mash because the enzymes were not inhibited by a high concentration of sugar."

Could it be that it is actually correct that BIABers are finding good attenuation from their beers because although beta amylase is retarded do to the lower concentration, this is balanced by the lower concentration of sugar, allowing more "complete" conversion?

 

[Thirsty Boy]

I don't know if its safe to bring this up again :unsure: , but I was reading this article which mentions that a "Thin mash dilutes concentration of enzymes slowing conversion, but leads to a more fermentable mash because the enzymes were not inhibited by a high concentration of sugar."

Could it be that it is actually correct that BIABers are finding good attenuation from their beers because although beta amylase is retarded do to the lower concentration, this is balanced by the lower concentration of sugar, allowing more "complete" conversion?

Exactly !!! I pointed this (possible) effect out in an earlier post, but it seems to have gotten a bit lost in some of the shouting thats happened here since last I looked.

At risk of kicking it all off again, I'll shove in my 2 cent's worth (besides, I missed the chance to stir the pot before due to being away on holidays)

Firstly, I need to take a little offence. A little offence on behalf of the word science. Science has been being tossed about this thread recently as though it were the pointy end of a spear. There is another word starting with S that is appropriate for the situations I have seen science shoe-horned into lately, and its scripture. "The big book with all the knowledge in it tells us that it must be so.... and therefore it IS so" Sorry, but that isn't the science that I studied at university! It certainly isn't the science that is responsible for discovering new and wonderful things that make us re-evaluate the stuff that we thought we new. Science is about testing in a controlled fashion, looking at your results and coming up with a theory to explain your observations (not necessarily in that order) if your theory fails to match the observed results, then no matter how much pre-existing knowledge and experience says that its correct, it isn't.

So in the context of this thread. If "science" tells us that a very thin mash will always lead to an overly dextrinous wort, then any (repeatable of course) example where this does not happen means that the "science" is wrong. Doesn't matter how many times it DID produce a dextrinous wort, one time where it doesn't and the theory is wrong. Period, no dancing around objecting, just wrong.

So you put your thinking cap on and try to work out why. Do some more experiments, refine your ideas till what you think and what you see match. And when it does, and you're finally right; here's a clue. Writing it down in a textbook doesn't mean it will still be right tomorrow. NO matter how much you might wish it did.

Sorry. Rant over.

Couple of more practical points to privide food for thought on some of the very real concerns that have been presented with regards to Full Volume Mashing.

Beta enzymes - They still work just fine in thin mash. As pointed out by Phonos, more slowly, but in the end both they and the alphas will actually convert more completely because they aren't inhibited by their own byproducts. Thin mashes will however make them significantly more vulnerable to temperature variations. There also seems to be some confusion between optimum temps and de-naturing. Just because Betas dont work all that well at higher temps, that doesn't mean they have all been killed off. Take the temp back down into their range and there will be more than enough left over to start working again. I've done a reverse mash where I started at 70C and let the mash tun cool down to 62 over an hour or so. If all the Betas were denatured at the higher temps my wort would have been virtually unfermentable. But it wasn't. (see next point)

Alpha enzymes - Help Beta enzymes to work!! Think about it. Betas bite small fermentable (Maltose) sugars off the ends of starch chains. Alphas attack the starch chains randomly. They might bite off a glucose, or they might just knock it in half into 2 dextrines. Each time they knock a starch molecule into 2 dextrines, there are more ends for the Beta enzymes to work on. this is why if you mash low for a fermentable wort, you need to give it a bit of time. Betas only nibble away, but the alphas give them more ends to chew on. Single infusion mashes at compromise temperatures work just because of this.

Sweetness in beer - (Warning, I'm far from 100% sure that this is in fact true) Its my understanding that dextrines dont actually taste sweet !! They add body and mouthfeel to a beer, but they dont actually add sweetness. The sweetness is a result of fermentable sugars that the yeast have failed to ferment for whatever reason. I've tasted pretty much everything that I've put into a beer, and the dextrine based "body" improvers that my LHBS carries certainly dont taste sweet at all. Neither do any of the beers that I have brewed at higher temperatures to give them a dextrinous character, have indeed finished out with a higher FG and a heavier body, but yet, not sweet. This would mean that if you experience sweetness in your beer, its a result of something other that mash derived dextrines and high L:G ratios aren't the cause. If you know better than me, please correct me on this.

Conversion - Jeez, modern malts are so well modified that you have to go looking for a malt that makes it anything other than an exercise in bloody mindedness to do a decoction on! We all know that the greatest part of the conversion action is over in 20mins. So maybe BIAB takes twice as long?? Still less than the 60mins that most people mash for anyway. PM suggested that it might be a good idea to use a really High DP malt like galaxy if you want to go with BIAB. In general I suspect that that is playing it overly safe. On the other hand... if you are talking about brewing a beer with lots of adjunct, or at the ends of the amalayse temperature ranges, I think that that might be really good advice. If BIAB is a bit harsh on enzymes, throw more at it !! Hell, its not like Galaxy is a base malt you want to avoid.

Enough. Those are a few facts (sort of and I hope) about mashing and conversion. None of them I believe contradict the facts that have been presented by (among others) Dr K; and yet I draw a different conclusion than he does about what they mean with regard to BIAB. Oh well, thats science for you.

I say lets keep trying. There simply isn't enough experience out there to tell one way or the other. As we go along, we will find out new things. People will decide that BIAB isn't giving them the results they want, and they will move on (already happened) others will decide that the ease of the method tempts them away from their mash tun. The first people who decided that they didn't need to do a decotion mash were probably nailed to the side of a brewery because you couldn't possibly make good beer any other way. But in the end they were right. Maybe BIAB will be such a step for home brewing. Maybe it will just be a side excursion that leads us all back to our mash tuns. We will be the wiser in either case.

I for one like the ease of the BIAB method enough, that I plan to conduct all my "pilot" brewing in this fashion. 10 or so litre batches to try out new styles and new recipes. Hopefully the process of translating the recipes developed using BIAB to my 3 vessle system for full sized batches will give a good comparison of the results produced by the 2 methods. Will they be the same? probably not. But the same recipe brewed on 2 different systems is never the same. Question is, will the difference be bigger between BIAB and non than between 2 non-BIAB systems??

I hope BIAB turns out to be an ongoing viable method for producing great beer. The evidence so far suggests that it at the very least has great potential as a bridge between K&K/extract and AG brewing. The ease and low entry cost are powerful attractants for people who want to step up. Can I make beer this way that is as good as I could make on a 3 vessle system??? Only time will tell.

Thirsty

 

[Finite]

Wonderfull post Thirsty :excl: :beerbang:

Really cleared alot of things up for me regarding this method. Im going to be brewing my 3rd BIAB tomorrow and I keep finding that my attenuation is very good and im having no off results by having a thinner liqour to grist ratio.

I will ask one thing however. Baised on what you have said here, how long would you sudgest to do a mash for using a single infusion with BIAB? At the moment im doing 90min mashes.