How big and what material should my brew bag be?

[Brewer #480764]

Hey there!
Around a month ago i had made a post about wanting to upgrade to allgrain and asked for help and suggestions (thank you to all who commented and helped again your suggestions very really really usefull)
Before answering please note im from Turkey, we dont have a big homebrewing scene so its either stupidly expensive or impossible to get most if not all mainstream / brand equipment and supplies ( i cant even find protofloc tablets)
to give a short summary and update:

After some saving and research i have gotten a 39.7 liter stock pot, i am just about to finish my immersion chiller and have refurbished an old fridge i had in the office to use for lagering / cold room. i had an old 1500W heater and im going to get a second 1500w immersion heater to help bring it to boil fast. I found a malt shop that has some beer malts and they sell pre crushed

My question is: 1 how big should my brew bag be? in a local brewing forum i found a sewing sheet that makes a cone bag with the formula: Top= diameter x 3.14 x 0.5 x 1.20 Height= pot height x 1.15 + 2.5 bottom = diameter x 0.85
my pot has a diameter of 35cms and height of 38cms, when i put the numbers in the brew bag i get should be about 47-48 liters, asking ai it gave me: 72cm top, 42 height, 35 bottom. should be around 90 liters? is this any better?
another thing i keep seing is to just make a rectangle and sew a circle to the bottom but i dont have the formula for that. which should i use? is this right?
Sewing is not a problem i have a relative who used to work as a tailor so she will do it for me.
question 2 is what should my material be? after some research i had bought around a meter of voile textile its like a cheesecloth but more durable and with denser holes. But asking ai etc says its not right because its made out of cotton. Would cotton be too much of a problem? do you have any better ideas?

question 3, any other things i could / should get for my setup? a grain mill is on my list to buy but they are stupid expensive :/ im open to suggestions

Im thinking about making an octoberfest beer for my first beer on this setup, since i can use all the parts of the new kit and octoberfest was the first time i had beer, feels right for it to be my first all grain too
Any recipe recomendations for my second? im using a recipe book by greg hughes

 

[Donoroto]

Size: typically a cylinder about the same diameter of the pot, but perhaps 30 cm taller. The bag is normally in contact with the metal pot, and you want extra height (length) so it can be draped back over the outside of the pot and secured - you don't want the ends falling in, as the hot wort make it hard to grab the ends later, when you want to lift it (and the grain) out.

Use the formula W=d*pi. W is the width of the fabric before sewing, not including a few extra cm for sewing. d is the diameter of the pot, and pi is 3.14. The bottom is a circle, use the pot as a guide, but allow a few cm more for sewing.

Material: cotton is ok, but it will absorb color and flavor from the wort. It might be not good after a half-dozen brews, but don’t waste it, use it for now. Nylon or polyester is better. Tuelle is a similar fabric: you want a fairly tight weave. Muslin is also ok (but usually cotton), cheesecloth is not fine enough.

The only result from too loose a weave is some grain in the boil. Not a huge problem, but better avoided.

Equipment: a hydrometer or refractometer, a scale good down to 0.1 gram, a stirrer spoon, thick rubber gloves (to lift the hot bag), a place to put the hot, dripping bag of grain (a sink?), a thermometer and some way to get the boiled wort into the fermenter.

1500 watts is a lot: too much heat can ‘burn’ or scorch the wort, if the heating coil is directly in the wort (immersed). Better is something under the pot (think ‘cooking stove’). If immersion is required, go slower and stir almost continuously.

If you can get ground grain, wait on a mill. Have them grind it extra fine, almost like flour. Twice through the mill is good.

Pick a beer you have made before if you can. Being familiar with the goal will help you better understand how this set up will change your results. Brewing a completely new beer style won’t much help you understand how brew in a bag is different. That being said, it’s not that critical: if you really want an Oktoberfest, Brew an Oktoberfest. It will be beer.

 

[Sandy Feet]

You will have to brew small batches with a 10 gallon pot. BIAB is full volume. During the hot break you will overflow it making a 5-Gallon batch (19L).
For me, a 5 gallon batch starts with 8 gallons of water.
If you can find a false bottom, that might help to not burn your bag. Make sure you have the plumbing (ball valve) on your pot for transferring to the fermenter. You will want a very good pair of gloves for draining the bag. A controller for the fridge?
Book: John Palmer How to Brew.

 

[Zambi]

You will have to brew small batches with a 10 gallon pot. BIAB is full volume. During the hot break you will overflow it making a 5-Gallon batch (19L).
For me, a 5 gallon batch starts with 8 gallons of water.
If you can find a false bottom, that might help to not burn your bag. Make sure you have the plumbing (ball valve) on your pot for transferring to the fermenter. You will want a very good pair of gloves for draining the bag. A controller for the fridge?
Book: John Palmer How to Brew.

I'm pretty sure you will be fine making 19 litres batches in a 40 litre pot....
Just keep an eye on it.

How are you going to lift the bag? Just hand power?
It will be heavy.

Note on using recipes:
Most American are based on 19 litres, a lot of European ones use 10 litre as a base figure (easy to upscale in metric).

 

[Sandy Feet]

I'm pretty sure you will be fine making 19 litres batches in a 40 litre pot....
Just keep an eye on it.

How are you going to lift the bag? Just hand power?
It will be heavy.

Note on using recipes:
Most American are based on 19 litres, a lot of European ones use 10 litre as a base figure (easy to upscale in metric).

It probably depends on how much energy you have on it at the boil and what you are making. I use a Blichmann burner. During the hot break, it will foam about 7/8 or more up my kettle, and my kettle is close to 60L.
I agree about the weight of the bag for the 5 gallons. I use a pulley attached to a ladder. If you are strong, you can get away with a grill grate on top of the kettle. I used that method for awhile before I realized it was a pain in the ass.

 

[Minbari]

polyester voile is what is usually used to make the bags.

 

[Donoroto]

Hot break can be managed with a spray bottle of water. Just spray the rapidly-rising foam to keep it down.

 

[Zefram]

After a few (mindless) boil overs, I started using FermCap and have not had any issues with out of control hot break. Cheap insurance, but it also allows one to stretch their capacity.

 

[Zambi]

It probably depends on how much energy you have on it at the boil and what you are making. I use a Blichmann burner. During the hot break, it will foam about 7/8 or more up my kettle, and my kettle is close to 60L.

Yeah, makes sense.
I use my gas stove (as I only make small batches), and it's pretty slow.

There are some ways to increase volume, but I don't want to confuse OP just yet