Course-weave BIAB Bag?

Does anyone use a bag with a weave this coarse for BIAB? If so, what are your experiences? It's the same weave as a nylon hop bag.

I've seen in other posts that some BIAB-ers use a course-weave straining bag made by L.D. Carlson. If you use that bag, please tell me--is its weave as course as the weave you see in my photo?

I used to use a paint strainer bag about that coarse. Depending on how finely you grind the grain, it should work. I was using a finer bag and grinding pretty fine, but when I switched to the coarse bag, I got 6 batches in a row that were pretty astringent. I traced it back to the switch in the bag coarseness, and getting more draff into the boil kettle.

I also tried the lauter-in-bag method, and got good results with the coarse bag. It just took a while to vorlauf all the grain bits out, and it's easier to just use a finer bag.

That weave looks similar to my BIAB bag. I have no issues to report. Works great!

frailn said:

That weave looks similar to my BIAB bag. I have no issues to report. Works great!

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How fine is your crush, frail? I have close to 10 lbs of double crushed grains, including Maris Otter I had to mail-order, and if this is not the right bag to use, I'll take it back to the LHBS rather than take a chance on my winter warmer. I've really been looking forward to this brew.

FWIW I was having my issues with milling conditioned grain at about 25-30mil. I switched to 45mil and the coarse bag worked ok, but still had more draff than I cared for without vorlaufing. I've switched to a proper MLT since then, which makes vorlaufing much easier.

tonyolympia said:

How fine is your crush, frail? I have close to 10 lbs of double crushed grains, including Maris Otter I had to mail-order, and if this is not the right bag to use, I'll take it back to the LHBS rather than take a chance on my winter warmer. I've really been looking forward to this brew.

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I have my LHBS double mill my grain. Not sure how fine the crush is, because I don't have access to the mill behind the counter. I can't really say if I have too much trub, because I don't have anything else to compare to in my limited experience. Since the cost is low on these bags, I would recommend trying a finer weave if you have any concern. Or you could calculate your water volumes to account for more trub in the BK and/or fermenter.

Nateo said:

I used to use a paint strainer bag about that coarse. Depending on how finely you grind the grain, it should work. I was using a finer bag and grinding pretty fine, but when I switched to the coarse bag, I got 6 batches in a row that were pretty astringent. I traced it back to the switch in the bag coarseness, and getting more draff into the boil kettle.

I also tried the lauter-in-bag method, and got good results with the coarse bag. It just took a while to vorlauf all the grain bits out, and it's easier to just use a finer bag.

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How much draff were you getting in the kettle? I may have had this problem as well in the past and am wondering if my bag may be too course.

Where can you find less course paint strainer bags?

Draff - meaning husk material? If so, then I have noticed some, but I always thought it was from my bag slipping when I stir the mash, and having to pull it back up. I have started re-straining going into my ale pail, and I don't end up with any husks in the final brew that I can tell.

After the mash, I throw the bag into the washing machine, then into a bucket of star san. Then I fit it into my ale pail, and dump the cooled wort into the bucket. It catches the hop trub and any husks that may be lurking around.

I have been thinking about switching to a custom sewn bag made from voille, rather than using the course bag I use which I purchased from the LHBS. I think a tighter weave would always be better.

But for now, there is not enough husk material to make much, if any, difference.

I used to use some cheesecloth bags my wife sewed up for me, but they disappeared somewhere. I suspect my mother-in-law threw them away when she was doing the washing after coming over for dinner. But anyway, they're gone so I bought some paint strainer bags, and had a bunch of problems with astringency.

You can buy cheesecloth by the yard at fabric stores. It comes in different coarsenesses, and I'm not sure what you'd call the different grades, but it was pretty fine. So you can just buy a couple yards and sew them together to make a bag.

I was getting probably 1-2" of draff (bits of grain husk and endosperm) collecting in the bottom of the fermentor, more than the thin layer I was getting previously. I traced the astringency back to too much grain in the boil.

I don't think my problem is very common, and you probably won't have any issues, but just a bit of warning.

Would doubling up with 2 paint strainer bags cut down on the amount of bits getting through? Or should I just look into getting some better bags?

Now you have me worried. My last 2 batches have been BIAB using paint strainer bags and I have way more junk in the bottom of my fermenters that I use to. A good 2 inches or more. I also use these same bags for my Hop pellets so my Plate chiller doesn't get clogged.
Would wracking to the secondary sooner help or is it too late?

From what I understand, astringency is only extracted from husks at high temps above mash temps (otherwise all our beer would be super astringent right?). So once you're done with the boil the husks really wont make too much difference I don't imagine. It's husks in the boil the cause the bad flavor.

I tried doubling up the coarse bags, and that didn't really help. I really noticed the astringency on lighter-in-color beers. Darker weren't as noticeable.

Zeekage is right, it's the husks (and I'm convinced endosperm too) in the boil that extracts tannins. Once it's boiled, what's done is done.

@Nate it's possible your beers are fine, but if they're not, I'd start with the bags. AFAIK, all the aussies who came up with BIAB used very fine voile.

Thanks for the discussion, everyone. I ended up taking my course-weave nylon bag back to the LHBS for store credit. I'll make a big BIAB when I have the time to get some voile and sew it up.

Though I'd been looking forward to mashing 10 lbs of grain all at once in a big bag, for my winter warmer brew day this weekend, I think I'll try my luck with reiterating mashing, BIAB-style. That's two mashes in two (smaller) paint strainer bags, the first mash in water, the second mash in the wort created by the first. With decent efficiency, the result should be a high-gravity wort, as much as 1.090, made with humble equipment on my stovetop, without having to boil forever.

There's an excellent Basic Brewing podcast on reiterated mashing, definitely worth looking up.

http://media.libsyn.com/media/basicbrewing/bbr11-22-07reiterated.mp3

Some people just go to Walmart and buy a Voile curtain and don't sew them into bags. It's a bit crude for me but if you are careful it is a cheap easy way to get BIAB done. I have several of the coarse bags shown in the OP and wouldn't consider using them for my BIAB. I had some overpriced bags made for my use and get very clear wort for the boil.

I've just ordered from here:
http://custombiab.blogspot.com/

Very excited to see the results from my next brew.

sjjn said:

I've just ordered from here:
http://custombiab.blogspot.com/

Very excited to see the results from my next brew.

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Very cool. I may have to order one of these. Way better than what I could come up with.

Also, check out this BIAB Bag maker and HBT forum member if you live in the USA.

http://www.brewinabag.weebly.com

frailn said:

Also, check out this BIAB Bag maker and HBT forum member if you live in the USA.

http://www.brewinabag.weebly.com

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brewinabag.weebly.com is now bagbrewer.com

I used to use 5 gallon paint strainer bags. NO astringency problems, but I did get a lot of trub in the bottom of the primary fermenter. Almost 1 gallons worth, so it was chewing into my finished beer volume.

I still use the paint strainer bag on the inside and a voile bag I sewed from curtains as the main bag. I've noticed I'm back to 1/2 to 2/3 of a gallon of trub and get an additional 6'er of bottles at packaging.

I've noticed absolutely no change in taste between the two. I even tried a batch that was whirlpooled, leaving most of the break behind in the brew kettle. No difference in taste from just throwing it all into the fermenter. And whirlpooling is a PITA. Two pennies.

Paint strainer bags are a little coarse but will work for smaller batches, polyester voile material is a very fine weave and works very well, and can be found at fabric stores, Target, KMart, Walmart, etc.

I use the paint strainers at home and end up with a fair amount of flour in the boil. Don't get any astringency at all, and the beers clear up just fine. All my grains are double-crushed at the LHBS standard mill setting.