Brew In A Bag, or BIAB, is a method of making beer that seems to be gaining in popularity, likely because it is a very easy way to jump into all-grain for experienced extract and brand new brewers. Admittedly, this is the method I use the least, though it’s the only way to go when I’m making a small batch. Another reason I’ve chosen BIAB over my standard batch sparge process is when the grist of the beer I’m making consists of high amounts of grains rich in beta glucan, as it is impossible to get a stuck sparge using this method. For a more detailed review of my BIAB process, check out my prior blog post, Brew In A Bag: All Grain Brewing Made Very Easy.
I always mill my grain and collect my brewing water the night prior to brewing; in the case of BIAB, the grain is milled directly into the bag.
Here’s what a typical BIAB brew day looks like:
- Heat full volume of brewing water water to ~7˚F above target strike temp
- Add bag full of grains to brewing liquor, stir to reach mash temp, cover kettle with sleeping bag, set timer for 60 minutes
- Check mash temp every 10-15 minutes, turn burner on very low and stir to maintain temp
- Once mash is complete, slowly remove grain bag and twist to squeeze wort out
- Start boil and make hop additions as usual
- Clean grain bag while wort is boiling
- When boil is complete, chill to pitching temp, transfer wort to carboy
- Place carboy in fermentation chamber, clean kettle, put everything away
- Pitch yeast and wait…
BIAB is a truly fantastic method for making delicious all-grain beer. If you have a friend who’s considering getting into the hobby, I highly recommend you consider helping
41 thoughts on “Brew In A Bag (BIAB)”
I’m currently an extract brewer looking to get into the all grain game (still working hard to afford all the MLT equipment, etc.) and this seems like a good way to start without needing to buy everything up front. What are some suggestions you have regarding efficiency? Can I pretty much buy the same amount of grain as the recipe calls for and what about the impact to OG and FG?
Just found this website through the wonderful world of Reddit and have been devouring everything I can, thanks for the good work!
As far as efficiency goes, you probably won’t know until you brew a couple batches. Stirring every 20 min seems to help with consistent efficiency, as does squeezing the bag. Cheers!
Just started with BIAB (3 batches in so far), and so far each one has been above 70% efficiency (most recent was 76%). I haven’t made any modifications to recipes and each batch has turned out great (hit or exceeded OG each time)! My process has an added step that was recommended to boost efficiency.
First, rather than mash with the entire pre-boil volume of water, I mash with a gallon less so that I can rinse the grains after mashing is done. After mash is complete, I transfer the brew bag from the kettle (after holding above the wort for a minute or so to drain) to my bottling bucket with spigot, which has an upside down colander sitting on the bottom. I sit the brew bag on top of the colander, then start heating the wort in the kettle. I let the grains drain for 10 minutes or so, then transfer those runnings to the kettle. After that, I add about a gallon of water heated to 168F to the bottling bucket with the bag of grains and let that sit for a few minutes, then drain that into the kettle until I achieve the desired pre-boil volume.
I’m not sure how much of an effect this extra drain/rinse step has on boosting efficiency, but as I’ve been turning out good beer, I haven’t messed with it at all. Sure, it isn’t as simple as straight BIAB, but since I usually have to wait at least 30 minutes or so for my shitty stove top to heat the wort to boiling, I might as well be doing something during that time.
Yeah, that’s actually a pretty common method that is sort of a modified “sparge.” I’ve done it and noticed not significant impact on my efficiency, hence I don’t do it anymore. But, hey, I’m all for doing whatever works best for you!
I tried this method 3 times & didn’t care for it due to; inconsistent high efficiency (77%, 78%, 84%) and it was messy with the bag dripping on the garage floor while moving the bag from one kettle to the other. I did modify that technique to one I’m happy with & results are scary consistent; mash in 4.5 gallons of water & heat remaining 2.5 gal to 190* in another kettle on my stove, after mash is complete I add the second batch of water directly into my mash, this gets me really close to “mash out” temp so adding a little heat fixes that. I pull the bag, drip drain, a little squeeze here, a little squeeze there and I’m off to the races!
I’ve tried BIAB once and I used a second smaller kettle to “sparge” by dunking the bag in 170 degree water after the original 60 minute rest. But I was thinking about trying it a different way.
Have you ever tried or thought about leaving the bag in the kettle you are mashing in and turning on your burner until it reaches sparge temps and THEN taking it out? What kind of effect do you think that might have?
That’s exactly how many people do it, it’s referred to as a mashout and it works fine.
Would this require a false bottom so I don’t scorch by bag and grains at the bottom of the kettle?
I don’t start the burner until the bag is removed, but if you want to mash out, yeah, a false bottom is a good idea.
“Add bag full of grains to brewing liquor, stir to reach mash temp, cover kettle with sleeping bag, set timer for 60 minutes.”
The above statement is confusing to me. I assume you meant “steeping bag”, and the kettle lid is what I should cover it with?
Also, the bags I have found with my research so far seem to line the inside of my brewing kettle. Is there any concern with the grains sitting on the bottom of the hot kettle, or should I try to suspend it as it steeps similar to how it is done in extract brewing?
Thanks in advance for the help!
I’m considering a move from extract to BIAB with the help of your great articles.
Haha. No, I actually meant “cover kettle with sleeping bag,” which serves to insulate the kettle and limit heat loss. The grain (steeping) bag absolutely goes inside the kettle.
If you have any further questions, please don’t hesitate to email me directly. Cheers!
Yep, big fan of this method too. I started doing BIAB back in October 2012 and still going with it now with no plans to move onto 3V setups or anything like that. I actually have a hot water urn, rather than a kettle and gas burner. I’m really happy with the results I’m getting and have worked out my system over this time to be able to create recipes pretty accurately in Beersmith and have them turn out as planned. Can’t ask for much more than that really. 🙂
I occasionally perform a modified BIAB with a portion of the wort I collect from a larger batch. I have done this for efficiency in time when I make a series of beers of similar profile. For example, I recently brewed an 11 gallon batch of ESB (so bout 14 gal preboil vol.). Divert 9 gal to my BK (boil kettle) and finish as normal.
Normal for me is 8-9 gal. prB vol. (preboil vol) at about 6-8 pts lower than my cooled knockout OG. This achieves my 6 gal of cooled wort in my BK & thus 5.5 gal to FV (fermentation vessel).
Now I take the 5 remaining gallons of wort and experiment. For ESB wort I dilute the wort to either Best or Ordinary prBG (preboil gravity). Add some other malts, as desired, in a bag (ie Brown, Biscuit, Aromatic, Spec B, C120), and mash in the wort as I slowly raise to mash out temps. Add more hops if needed. Finish as normal.
I’ve also done this with Hefeweiss wort. With that I mashed (in a BIAB sack) with a few lbs of Munich and Vienna to make a Dunkelweiss and Weizenbock.
Two or three beers. One or several types of yeast. One clean up.
I’m really interested in trying this method. I started with kits, then basic extract and have done half a dozen partial mash brews but love the idea of BIAB mainly due to the cost of Malt Extract. Would it work at well using partial mash volumes i.e. 10-12L mash and then topping up in the primary fermenter? Thanks in advance Alan
It seems you didn’t finish writing the last sentence of your post.
It’s a great post anyway. BIAB is so easy and simple that convinced me to get into the hobby.
This may be a dumb question, but when you take your pre boil gravity reading to calculate efficiency, do you have to correct the hydrometer reading for temperature or does beersmith already take that into account?
Not dumb. Good question.
You need to either cool the sample to the temperature at which the hydrometer was calibrated (ie 60,65,68F), or you need to correct for the difference. There are often charts that accompany the hydrometer or you can find load if online calculators.
Hope this is still an active thread. Lots of good ideas! Brewed BIAB other day and am wondering would there be benefit to draining off about a gallon or so of post mash wort when bag is raised and draining and pouring those runnings over the grains while still in the draining bag? Would that help with efficiency?
I’ve tried something similar and it didn’t do a thing.
I remove my BIAB grains from the bag and place them in a fine mesh colander over the kettle. I then sparge my grains using the heated wort first, then with water heated to 140°F. Try a taste test of your grains. Set aside an ounce or so of the grains before sparging them. After sparging the rest of the grains with wort and hot water, do a taste comparison. Compared to the sparged grains, the sugar content in the un-sparged grains is very noticeable.
Greeting!
I just all the rest of the things i need to do BIB…quite a few have mentioned “mash out”- But I have not seen it mentioned here- that is at the end of the 60 minutes raise the temp to 170` for 10 minutes to increase the efficiency-
Just wondering is it worth it?
Thanks
Brew Steady!!
In my experience, a mashout step is not necessary, and while we have an xBmt planned to test it out, I forgo it whenever I brew BIAB or otherwise.
Great News- Thanks
When will we see that xBmt?
Well Gents- I have my first pint of my first BIAB all grain brew- TODAY
I kit I got from Jasper’s- Cold Hard Bi!@#- very nice- not bad for my first BIAB.
Getting the water amount was a little tricky as I got different amounts in different places.
The advice on the BIAB web site is pretty good I found. 10 days fermenting in primary- 3 days with dry hops and into the Keg- hopefully it will clear up a little more but other wise no complaints.
Marshall- thanks for the advice and the experiments!
Brew Steady!
Peace
I have had some attenuation issues with BIAB (consistently getting around 65%). I lift the bag up and start the burner to maintain mash temp throughout a 60 min mash. My though is that with direct heat I am denaturing beta-amylase resulting in a less fermentable wort.
I recently picked up a HERMS coil to modify an electric kettle I have to do kind of a “recirculating mash BIAB”.
Has anyone tried anything like this?
Sounds like you’re having efficiency issues, and to be honest, 65% is totally fine. Unless you’re actually struggling with getting fermentation to fully complete (attenuation), but that’d be an odd thing to blame on BIAB.
I’ve tried one BIAB batch and had a very similar issue. No matter what I did, it wouldn’t ferment beyond 1.030. I’ve brewed 3 extract batches that had the same fermentation conditions, and they all fully attenuated quickly. I even used the yeast cake from the BIAB batch on my latest extract batch just to test a theory, and it fermented violently and made a delicious beer. I’m trying BIAB again next weekend, this time with a better thermometer, an iodine test, and ph strips.
I sort of saw this question above, but no answer. Can one mash with less water and then top off in the brew kettle before boiling? I have an old 5 gal Igloo and I am too cheap to buy a 10 gal. I did BIAB in my brew kettle, but as many have pointed out, it was hard to maintain temp.
Yeah. I would recommend using software like BeerSmith to determine proper volumes to mash and top off with to achieve the right OG.
Just started biab this weekend after doing batch sparging for a couple years. Couple questions
Is the addition of 6ml of lactic acid appropriate for a 7 gallon batch, which has an 11 lb grain bill and 7.3 water pH?
Is it appropriate instead of making to a certain time to keep checking gravity, and end the mag when you got your predicted preboil gravity? I.e. allowing higher efficiency to shorten mash rather than increase abv?
1. Completely depends on your starting water. But 6 mL is probably fine.
2. I’m drunk and have no clue what you’re asking 🍻
I’ve been doing this although I use just though water for a normal mash, not the full amount. I was led to believe that too much water dilutes the enzymes and reduced efficiency. Anyway, I use an iodine test to evaluate conversion and have achieved full conversion in 60-90 minutes with very high efficiency, generally exceeding what BeerSmith defaults to. I then take the rest of the water and bounce the bag in it for a while as a kind of sparge. Last batch I was within one point off the target OG for a normal mash.
I place the bag in a Bayou Classic 30 quart perforated basket and hold it in place with metal clips at the top of the basket. I pour the milled grains into the bag, and I then lower this perforated basket into the brew kettle of hot water. I mash the grains at 154 degrees for 60 minutes, and i then mash them an additional 15 minutes at 170 degrees. Every 15 minutes I use the large kettle spoon to stir the grains in the bag for less than a minute. Here is a link to information regarding the perforated basket:
https://www.amazon.com/Bayou-Classic-B300-Perforated-Accessory/dp/B00062VZOW
The perforated baskets come in various sizes to fit average size and large kettles. I have used this method to brew good tasting ales and lagers.
Hey Marshall,
It looks like this description of your process is pretty old. Have you changed anything since moving to electric? Are you still using a sleeping bag to insulate your kettle?
Actually, yeah, I’ve changed a few things. I’ll look into making an update soon!
I do use BIAB exclusively and use a sous vide to maintain temp. It’s a breeze.
hey! im starting BIAB and i was asking myself if it is important to have a ratio for water/grain when i mash??? im doing 1 pounds of grain for 1.5 liters of water and then sparge to complete my desired volume. last brew i sparge 2.2 gallons of water.. is it too much???
You should be a-ok.
sry for the english maybe im talking french ahha
It sounds like you add grains to bag and then the whole lot to the heated strike water. Does this not cause more doughballs?