How to go from Extract to AG for < $10.00

[staldor]

Hi! I have a question about mesh size. Have anyone experienced tannin taste because of bags with too coarse mesh size? I have tried to do biag with the following bag from brouwland.com that probably has a bit too coars bottom


Especially on the light colored beers i notice a kind of bitter aftertaste that makes it rather undrinkable. Almost a bit slimey taste. Is this likely do be due to the to coars bag? And how fine does the bag need to be in numbers (micron)?

[Hop]

So, I've been formulating a BIAB plan. My plan goes something like this:

Get a big polyester or nylon bag with a drawstring (like a laundry or sports bag).

Get one or two finer mesh bags available from places like MoreBeer or Northern Brewer--enough to hold 15+ lbs of grain.

Brew with the smaller bag(s) in the larger bag, and use the larger bag to shoulder all the weight from the water-saturated grain when it's dripping.

I don't plan on going with a finer crush than I normally would for a few reasons. Mainly, I don't like husks being ground-up because they can give a beer undesirable flavors. The coarser grind will also steal less of my precious wort when dripping out. I'm also willing to mash for an extra 30 minutes if I need to.

Does anyone see anything wrong with this approach? If not, I'll probably start by trying this method rather than looking all around town for someone skilled enough to make me a bag out of curtains. If I make a $15 batch of beer with $15 of new supplies and it doesn't turn out, I'll chalk it up to another experimentation failure.

[PistolPatch]

Nice to see a few more people have been having a crack at BIAB. Just to help out with the last two posts...

staldor: It's a bit hard to see how coarse your bag is from the pic. The fact that I can see the grain so clearly through it tells me it probably is a bit too coarse but I don't think this would be the cause of your bitter/slimy aftertaste. I'm pretty sure this is totally unrelated. (See my note to "Hop" below as well.)

As for correct size mesh, have a scroll through the first few pages of this thread. SpillsMostofIt put a magnified pic of a coin on the material. Too give you another idea, if you put flour in the bag, a bit would fall through it but not much.

Hop: Having the small bags inside a large bag will not work well as you won't be able to agitate the grain freely inside the small bags and so your efficiency will be horrendous. A well-sewn nylon bag is heaps strong. You should also have no worries with a fine crush if your pH levels are okay - same as for any all-grain method. Then again, a coarse crush is fine too

To help with the making of bags I will try in the next post here to put up an FAQ written by ThirstyBoy and myself that I haven't as yet posted on [url]http://biabrewer.info/]BIABrewer[/url]

I'm not sure how I'll go posting it here as it has pics. Wish me luck

[PistolPatch]

Should I Make a Bag or Can I Buy One?

The bag is a critical part of the BIAB process. You need to have a bag that is of the right material, size, shape and strength.

Bags Designed by BIABrewer

BIABrewer has designed a bag that is tapered, elasticised, tabbed and designed to suit 40-100lt pots. It is quite complex and therefore expensive and time-consuming to make as a one-off item. As BIAB grows, BIABrewer, will look at finding a source of affordable bags to supply retailers. Until then, the bag specifications and use thereof have been provided free of charge to Gryphon Brewing (BIABrewer’s local retailer.)

If you are unable to purchase one, let’s have a look at how to make a perfectly adequate bag...

Material

The best material to make your bag from is sometimes known as “Swiss Voile.” This is a 100% polyester curtain sheer. It is a fine mesh, a lot finer than fly screen for your windows but not as fine as muslin cloth. If women’s stockings were the right shape and size, their porosity would probably be perfect! For instance, if you filled it up with flour and shook it, the flour would come through, but nothing else would. Water would fall through it without resistance.

So, if you are making your own bag, go for an un-dyed (e.g. white or ivory) polyester material that approaches the above description and you won’t go wrong.

Size

Size does matter! Your bag must be BIG enough to line your pot completely and without restricting the grain in any way. In BIAB you are not mashing “in a bag” you are mashing in a pot that just happens to be lined with a bag.

A fail-safe rule of thumb is that you need to be able to fit your pot inside the bag.

Design/Shape

The ideal BIAB bag shape is tapered, difficult to sew and hard to describe but simple shapes and designs such as pictured below work perfectly well. (Forget the carry straps though!)



(You might have to click on the above image to see the third shape properly.)

The third shape is very simple to make and works extremely well. It is based on a tapered pillow slip shape. All that needs to be done is to cut two pieces of material in the shape above and sew them together. Get your measurements from your kettle and cut your material to the following formula..

top = (kettle top circumference x 0.5) + 15%
height = kettle height + 15% + 2.5cm (1”) for drawstring or elastic.
base = kettle base diameter – 15%

A drawstring or elastic and tabs, hold the bag securely and allow lifting out of the kettle.

Stitching

Make sure all your stitching uses polyester thread. Use over-locking, or another form of strong stitch to sew your bag. Check the stitching regularly on your first few brews. The right material with strong stitching should give you a bag of indefinite life.

There you go!

[staldor]

staldor: It's a bit hard to see how coarse your bag is from the pic. The fact that I can see the grain so clearly through it tells me it probably is a bit too coarse but I don't think this would be the cause of your bitter/slimy aftertaste. I'm pretty sure this is totally unrelated. (See my note to "Hop" below as well.)

As for correct size mesh, have a scroll through the first few pages of this thread. SpillsMostofIt put a magnified pic of a coin on the material. Too give you another idea, if you put flour in the bag, a bit would fall through it but not much.

Thanks for the reply! Has anyone any ideas how a BIAG beer will taste if not using a fine enough bag (mesh size)? I'm not sure my tasting vocabulary is correct..

I tried a new BIAG session this weekend with a extra cotton fabric around the bag that filtered out all the fine particles. I hope this will help the beer turn out better.

Would a "85-95 mesh 124 micron" be fine enough? I found a big enough straining bag in nylon on ebay with this mesh size.

[jhollist]

Staldor,

I would really try to stick to the advice that has been given on the bags. The guys from Oz really have worked it out.

I got my fabric from: http://www.onlinefabricstore.net/sheer- ... abric-.htm

Just get a couple of yards, and cut it into a circle with a radius equal to the radius of the kettle plus the height plus a few about 15% extra. I had a drawstring sewed in on the top, but you can easily do with out it. The easiest way to cut a circle is to do the fold in half, in half ... trick. See here http://www.flickr.com/photos/smitten/696411765/ for a diagram. You then just cut to the length desired.

This does result in some excess fabric and (i believe) has led to some hot spots for me.

Cheers,
Jhollist

p.s. I recently did a demo for my brew club of BIAB. I did it simultaneously with a 55 gallon batch of stout being brewed on another members system. There was interest, especially with the new guy who had only done one extract batch. As I was brewing, I didn't take pictures. If i get some I'll post them!

[staldor]

That store had pretty hign postage cost to norway, but i found '118" Wide Voile Sheer White' on ebay with a nice price.

I hope it does the trick!

[Thirsty Boy]

I actually am not sure what affect it might have on taste to use a bag that is too course - I would be mainly concerned with physical effects.

BUT - the words bitter & slimey when used together - well that shouts alkaline to me.

Your dark beers are OK?? Your light beers are bitter, harsh and have a nasty mouthfeel?

Not BIAB - Water chemistry!!!

Do you measure your pH?? If not, I would get some pH strips and check it out. Read John Palmer's How to Brew and look for the Water chemistry, residual alkalinity parts - Listen to the Brew Strong series of episodes on Water Chemistry - obtain a local water report if you can - and consult the Residual Alkalinity Spreadsheets by John Palmer that are stuck to the top of the All Grain sub-forum.

I think thats where your problem is going to be. Its where I would look anyway.

TB