I’ve been brewing with a BIAB set-up for a while now and love the convenience but lately have been thinking about ways to increase my efficiency & quality and am debating on using the following techniques:
Dunk Sparge: Basically I would add a couple gallons less to my kettle/mashtun, put it in a second pot, and dunk the grain bag in it after removing it from the main kettle? Assuming the sparge water is set to 168f would this basically perform the function of a mash-out as well or would it still be beneficial to leave the bag in the kettle and bring it up to 168f?
Bag Squeezing: I’ve always heard this was bad news as it led to tannins & astringent beer but I came across this forum (http://www.biabrewer.info/viewtopic.php?f=21&t=586&hilit=squeeze) where everyone seems to be squeezing the bag for significant efficiency gains. Does anyone know if the squeeze technique actually affects the quality negatively?
Not fully mashing Dark/Crystal Grains: Has anyone experimented with adding the dark/caramel grains at a later point to minimise harshness? I heard Gordon Strong’s presentation where he strongly recommends only mashing pale grains. Any thoughts on how to implement this with a BIAB set up? Maybe just adding the dark malts for the final 30m of the mash? An added benefit was the ability to achieve a proper pH with less water treatment for darker styles.
What are your guys thoughts on incorporating these methods into my brew day?
I just brewed a stout weekend before last that was the first time I tried cold steeping the dark grains and adding the resultant liqour to the kettle. Taste test saturday (it was done! gotta love session beers) and the roast was present but very very smooth. I only steeped for about 4 hours but I doubled the amount of roasted grains from the last time I brewed this recipe. don’t know about crystal malts but it works well for roasted malts.
Hmm, makes me think of cold brewed coffee’s smoothness. A cold steep I assume is what it sounds like? Just soak the roasted grains in room temp water for some hours?
I don’t think the dunk sparge will work because of the temp. If your in the 148-157 your going to get more from your grains. At 168 your already past conversion temp and at the rinse temp. The squeezed method I’ve done and didn’t see a problem but others might have.
I’ve rinsed the BIAB bag with several different methods, and they all help with efficiency. I can get upper 80s or even 90+% efficiency if I rinse or sparge the bag.
Personally I have never squeezed a bag, I just let it drain by gravity and that’s it. I’m afraid of squeezing out tannins or starches. It isn’t necessary to risk this. You can get better extraction in other ways.
What I did for many years was a sort of Papazian old-style method, where I’d actually put the grain bag into a colander, heat up some water on the side to 170 F, then very slowly pour the water over the top of the bag in the colander. It’s very time consuming, and basically constitutes a sort of fly sparge but without the sparge arm. Kind of a pain, but it will get the efficiency way up even into the 90s.
I have also toyed with the dunk sparge method. This also works well and is almost as good as the colander method, I can get maybe upper 80s with this method.
And yes, I have also reserved the dark roasted grains for the end of the mash, and this definitely works. I would add mine in like the last 5-10 minutes of the mash. However this can also reduce color contribution so you might need to use a little more than the recipe specifies to get the right color and enough flavor. I need to experiment more with this to get it just right.
These are all great ideas and deserve more experimentation to find out what works best for YOU.
If your bag has a very fine mesh, then squeezing is fine. The issue is really only with something coarse like a muslin bag. Then you can get husk material passing through to the boil. This can lead to astringency in your beer.
Just like in batch sparging, I always tried to ensure I sparged with the same volume as the first runnings in a 50/50 ratio. Probably not necessary since this is more akin to a fly sparge, but that’s what I’ve done. Takes a long time to pour that much water through a nearly stuck sparge. The grains are ground very fine and it’s just a tiny stream of water being poured over the grain bag, maybe 1/2 the thickness of a pencil, something like that – very slow stream.
I’ve squeezed the bag without problems although you need to adjust down the volume of water for grain absorption because you’re pulling that liquor back out of the grains when you squeeze.
Drain the mash tun w/first runnings (add to kettle & start the boil)
Top off with 170f sparge water and stir
Let the grains sit for a few minutes
Drain the mash tun w/second runnings
Move the grain bag to the top of the tun and let it drain
Squeeze and compress the bag to collect as much run-off as possible
Condense these runnings on the stove-top and add to the kettle at flameout
The condensed runnings go from about a gallon to a few cups (or less). Thus far, I have not had any issues with squeezing the bag and get 80%+ efficiency.
I appreciate all the replies. As a follow up I had a couple thoughts:
By switching to a dunk sparge instead of a mahout in the main kettle would I be loosing some benefits by not having the grain sit in the kettle as the temperature travels from 152 to 168?
If using the cold steep method would I use the same amount of grains I initially intended to for the batch? I suppose this would produce a smoother result and stronger aroma than adding the dark grains at the end of the mash?
Mashout is usually unnecessary in a homebrewing setting where you can get your sweet wort up to a boil within a few minutes after the mash is done. It’s more useful for commercial brewers where it can take hours to get up to a full boil.
I was wondering what kind of efficiencies you were currently getting, although in my world I’m much more into consistency. The biggest thing thing that upped my biab efficiency what milling my own grain. My process is a little different because I mash in the bag in a 10gal cooler then transfer to kettle (I found adjusting temp on stovetop to be very difficult). I usually squeeze the bag and have never had a tannin issue because the tannins would be coming from higher ph sparge water (I don’t dunk sparge) or possible stringency from getting grain in the boil, but I doubt that either. I did increase my efficiency a lot by pouring 170F water through the bag at the end, but it was inconsistent and with my normal method of just squeezing I get 74% every time. If you are getting low efficiencies (in the 65% range) I would look to crush (mine is very fine) and mash PH.