Low tech brewing, and sewing a bag

My interest in brewing started whilst living with a homebrewer during my year in Australia. Beer there is expensive, so that was also part of my motivation. I like the low tech approach I experienced there. Water saving, for them, is a priority, so no chill is common, as is BIAB brewing.

Benefits of a Low Tech Approach

In the wet South West of England water is not a problem, however the low tech approach has several benefits for someone like me. Firstly, I live in a flat, space is an issue. Second, I am brewing mainly very highly carbonated beer (saison say) or very low (bitter etc). This means bottling is preferable to kegs, saving me a CO2 set up. I'm not worried about flushing everything with C02 either, because I don't really ever brew super hop forward american style beers, which react badly to oxygen. and will often be adding oxygen scavenging microbes like Brettanomyces. Having no chilling equipment also saves space and cuts down the length of a brewing session, which for my small batches is about 2.5 hours at the moment. I also find BIAB convenient because I often like to use "gummy" ingredients, which are no problem for a BIAB process.

Obviously BIAB doesn't  scale well to industrial sizes due to the requirement of lifting a bag, which needs to be tear resistant, and needs to be lifted in the first place. At the homebrew scale you can probably do bigger batches easier with three vessels, and it seems to create clearer wort. I also saw an experiment that seemed to suggest it can affect the perception of hops as well.

Making a Bag

Anyway I though I'd just give a quick overview of me making a BIAB bag. I bought Voile this time, which is a fabric of 100% nylon. I think it could also be other plastics, mine was nylon. Previously I have used muslin (cotton) which I can compost, but thought I'd try the plastic stuff this time. Good thing too, because a chap in front of me in the fabric shop had the roll of muslin and wanted all of it (150-ish m), the world is a fascinating place.

I use the old singer. Not as simple in form as a needle, but more than a modern sewing machine. I'm a pragmatist  I suppose. This machine is lovely. You can trace these by serial number. Victorian Scottish manufacturing, still going.

Basically its not rocket science, you cut the stuff, my fabric was already twice the height of the pot width-wise, so in length I just needed half the circumference of my pot, so that when folded left to right the top edges make the full circumference. The folded edge is the bottom, the sides get stitched. Excess is trimmed, and I guess you would normally turn clothes inside out at this point to hide the floppy bits of the seam. In beer making you don't want this, as the flappy bits are a hiding place for grains, so you want the flappy bits outside.

I have read some crazy plans for toroidal BIAB bags, which are somehow optimal (for maximising extraction per unit area of material?) Personally I feel if you are bright enough to make a torus out of material, it almost certainly isn't worth your time, just make an oversize "pillow case" such that the grain isn't constrained in the bag.

I trimmed the flappy bits and gave the bag a boil to finish.

Edit, having used the bag for the first time it is way better than my previous muslin ones. The friction is so low the grains just slide off with a rinse in the sink, my previous muslin bags had to go in the wash to remove all the caught bits of grain. It also seems to stain less and dry faster. Not having to go in the wash is a big plus because now my clothes don't have malt on them.