First BIAB - bad efficiency - bag to small?

Hey guys,

on monday i had my first BIAB batch. Positiv things were the very easy method and the short brewday. But i only got 9.5 litres with 13°P (~ 1.052) from about 2.5kg. Thats a bad efficiency. My first thought - my bag is to small for my vessel.
(other problem was a high vaporisation, but thats something easy to handle with).

Is it the small bag? My vessel is 30cm in heights and abput 37cm diameter. My bag got a smaller diameter. Got it from a local shop (in Germany, they git just one sice) but i guess i could buy a better one here: http://custombiab.com/
My mashing was a single-step-infusion at 68 °C for 70 minutes. Next time i would try a mashout at 75-78 °C before i remove the bag from the vessel.

What to do with the old one? For hops maybe?

But at least the brewday was finished in about 4 hours, my other system i used at my parents took me way longer.

Another question - with wich formular do you calculate your efficiency? Some time ago i read somewhere, that in the states another way or point of the brewingprocess is used to calculate it.

Thanks and have a nice weekend

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Thank you guys!

Pre-cook the Oats, the mash can better use geletanized sugars.

The way you buy them here in Germany is already good for that ("vorverkleistert")
At about 40 minutes of mashing time, temperature decreased to 65 °C. Maybe need some better isolation.

Ok, i orderd some voile and overlock polyester thread. (in different colours, but was cheaper :D - bag is white)

Did i understand that right - i cut two pieces of this (just a fast crappy skatch):

biab_modell_diy.jpg

and then sew those two together with the right measurements for my kettle - about 75cm on top, 37cm on height and 35 on the base, right?

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I'll have to say it again unfortunately but josh's maths are not correct. You did not get 50%, you achieved 66.5%. You can check this on any efficiency calculator such as this one here. (The answer you get will vary slightly depending on what grain you select).

So, you are only 3.5% different from your old brew.

My 50% are based on calculators from germany, the 70& as well. Im trying to see the difference between the efficiency calculations you guys do and those we are using here. One difference i see, we just use the total number of grains...

Efficiency = Volume of wort at the end of boil (100°C) (Litres) * Gravity (g/100mL) / Grainbill in kg

(To use the Volume at 20°C u can multiply with 0,96)

I will read more about that...

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The calculator you linked gives me 66%, right. (not all malts i used in this batch are available in the list - German Wheat Malt smoked with oak wood (this) for example - i used the normal "wheat malt", guess thats ok, i used a belgian "peated" malt, too)

I guess the difference is "the individual grains as they contain slightly different amounts of 'sugar.'"
It definitly makes sence to do this if you are using ingredients like flaked oat, but thats not allowed for commercial german beers (Reinheitsgebot) - of course we homebrewers dont care about that. Maybe thats the reason for the easy formula that i posted before.

Here is an example how we german homebrewers are used to calculate efficiency. (this website is from a german homebrewer, nothing commercial ofc)

Anyway - if i post something on this board, i will use your linked calculator. For the german one i have to use the ~50%

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Thank you a lot

I guess im going to find out, why everyone (!) is using this (maybe just old?) method of calculating efficiency in Germany.

Anyway, with my old system i got numbers between 80% and 87% based on

"Brew House Efficiency - An all inclusive measure of efficiency, which counts all losses to the fermentor. This can be thought of as 'to the fermentor' efficiency. Hops absorption factors into this, and is reduced on the same equipment by ~1% in super hoppy beers.

Gravity - OG (measured after cooling, before pitching yeast).
Volume - how much wort went into the fermentor."

So i will try to get the 70-75%. Starting with a larger bag, longer mashing time and mashout. Was my understanding of making it correct? (crappy drawing some posts before)
And ofc. i have to collect some more measurements, one batch is definitly not a number to relate to my brewingsystems effieciency.

And what raelly matters - getting a good homebrew, and thats what i always end up with (more or less, but never bad)



edit: another Link - this wiki is linked to our board. And no, no one ever wondered about different efficiency, because thats what really everyone is using - no confusings like EIF, EIK etc.

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the numbers you used to get of 80 and 87% on your old brews will have definitely come from a 'correct' calculator not the German one

Sure, i converted my old numbers with your linked calculator

Keep it Simple

On your next brew, remember to not only measure your volume into fermentor but also your kettle trub losses. Taking these two volume measurements means you can get both your 'efficiency into fermentor' and a 'kettle' efficiency.

Finally, help stop the cycle of abuse and never use the words, 'brewhouse efficiency' or an undefined 'efficiency' again .

I will do that

Messlatte_Einkocher.jpg

Thats my measuring stick for my kettle, guess i have to make something for my fermentation bucket.

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If, for some reason, you want to know your fermentor efficiency as well then just tip what trub is left in the kettle after transferring to the fermentor into some sort of measuring jug. Your end of boil volume X 0.96 - kettle trub will be your volume into fermentor. Put that number in as your volume figure into the efficiency calculator to get your into fermentor efficiency. That will save you having to find a dipstick for your fermentor. Personally, I wouldn't worry about the fermentor efficiency though.

Good idea

Got another question:

Never read about it in the english-speaking homebrewingscene - do you know "grünschlauchen"? Is there a word for?

It means to convert the wort quite before the fermentation finished to bottles/kegs to get a carbonisation without adding sugar or a need of forced carbonisation. (Not easy to hit the right point, ofc some risk of bottlebombs, easier with kegs)

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It sounds like you mean krausening or using speise to prime bottles (for carbonation)

Exactly NOT using "Speise" for carbonation. "Speise" is a part of the wort not added to the fermentation, what is "krausening"? (thats not a german word).

Otherwise can you offer a better alternative to translate?

No, thats why i asked

"Racking of beer that has not completed fermentation"

Yes, filling the not completely fermented beer into bottles/kegs without anything in addition to get the carbonisation from the "restextract" thats not fermented yet but later on in the bottles/kegs.

I guess there is no good short translation for that. Well, not important. I used this method some years ago, but its not easy. Now i let the beer completely ferment and then i add sugar when racking to bottles/kegs.

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