Use undersized bag til I make new one?

Post #1 made 3 months ago
Hi my most helpful brewing compadres!
For my first BIAB I used a cheap LD Carlson brew bag that was plenty big, too big, for my 10 gallon kettle. It made a good beer and dis not fall apart despite its loose weave. In the meantime I bought voile and made my own simple tapered pillow case design bag. Actually made 2 from the fabric I bought. I used a calculator that I assumed gave me cut dimensions factoring in seams etc. I enlisted grandma's help in sewing and I got the bags back to find then much too small. My kettle is 16.31" tall by 13.5" inner diameter, 14.75" top(lip) diameter. Cut my fabric to 26.6" top width, 11.5" bottom width, by 19.8" tall + 2" for drawstring 21.8" total. The resulting bag does just fit around the lip and touch the bottom, but the tapered bottom does not fully line the kettle and I certainly cant fit the whole kettle in the bag... not sure where I went wrong (other than the mistake of not just calculating myself.) The big question is though, while I'm waiting to make a new bigger bag can I use this bag without really messing up my mash or am I better off using the cheap bag that is definitely big enough? I am confident the undersized bag I have will stay put but it will probably constrain the grain a bit. I'll try to post photos later...
    • BME Brewer With Over 5 Brews From United States of America

Re: Use undersized bag til I make new one?

Post #2 made 3 months ago
Dread piratewes -
1) use the site search feature (upper right corner) to look for the word truncated See the third and fifth posts down on the hit list.
2) You could fill your small bag(s) with grains, tie them shut and put one or both in the mash step inside the bag that is too big. That way the smaller mesh of voile works in your favor and the larger bag with larger gaps still helps. Stirring mid-mash then becomes a matter of slow dunking of a small bag rather than actually stirring.

Re: Use undersized bag til I make new one?

Post #3 made 3 months ago
Thanks @ShorePoints I took a look at the truncated cone and decided to go with the tapered pillowcase design since I wasnt sewing it myself. It was easier to explain. I may just have to make one of those. Though I've heard people have had a lot of success with the tapered pillowcase as long as it's big enough :lol:
    • BME Brewer With Over 5 Brews From United States of America

Re: Use undersized bag til I make new one?

Post #4 made 3 months ago
Drewadpiratewes - Whatever works for your kettle and process will give beer. :drink:

https://www.biabrewer.info/viewtopic.ph ... nce#p53465 has an old answer of mine regarding how to make a bag. In it I describe how my wife made mine without any taper. The full circle of voile (wider than the lid, diameter reduced by the seam) is the bottom of my cylindrical bag. The vertical part was a rectangle, not an arc. I do use a metal vegetable steamer placed on the kettle bottom for separation to avoid melting the bag. The height of the bag gets adjusted so that the bottom just touches the vegetable steamer. The diameter of the bag stretches slightly to wrap around the kettle rim and then binder clips hold it in place. The inside wings of the binder clips fold down (not wet in the mash) to allow the kettle lid to sit flat. 70+ brews later, the bag looks used, but still works. Oh, no - I've probably jinxed it now. :sneak:

I believe that the thread count is a significant factor in success. Too coarse and particulates escape into the wort; too fine and draining becomes a problem (more so with rye malt). My local home brew shop continues to stock BIAB bags that have a too-low thread count. :idiot: :argh:
I wish I had access to the analytical instruments that could detect tannins and prove my theory that hand-squeezing the bag of spent grains at below mash-out temperature doesn't extract any more than not squeezing. That deserves to be tested with multiple grain combinations and temperatures to be sure, but then the myth can die.

Re: Use undersized bag til I make new one?

Post #6 made 3 months ago
The short answer is 35 threads per centimeter. At the fabric store, the material is called voile. It is more often used as curtain sheers. I recognized it as the translucent curtains behind the window draperies at grandma’s house. It is not tuile- that’s for other stuff.

See this one for more general info: https://www.biabrewer.info/viewtopic.php?f=53&t=37

And I found the number 35/ cm coming from PistolPatch, so I know that’s good. :thumbs:
https://www.biabrewer.info/viewtopic.php?p=51849#p51849
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