Miserable efficiency making it hard to follow recipes!

[poggor]

Hi guys- I have been doing some all grain brewing (BIAB) for the first time and Im having difficulty with my efficiency. Any advice would be greatly appreciated.

Today I wanted to make a bohemian pilsner. Im aiming for a finished batch of 17L


I mashed 5kg of finely milled grain in 12L of water in my esky at 68c. I lost a few degrees over the hour.
I squeezed the hell out of the grain bag over a colander and had 9L of wort (ie lost 3L to grain). Poured into kettle.
I sparged with 3L water at 77c by putting the grain bag back in the fresh hot water and stirring it around, squeezed, poured into kettle.

So 12 L in the kettle ready to boil.

My brewing software (beer alchemy) tells me that my pre boil gravity should be 1.085 (and this is at only 65% efficiency!) but i measured and after correcting for temperature it is only 1.070. Apparently this makes my efficiency about 53.7%

I can adjust my software to 54% efficiency but then I will have to make smaller batches. I have read the forum extensively and most people seem to be having no problems getting high efficiencies into the pot with BIAB.

Any suggestions?


cheers g

 

[spryzie]

Try more water. I think about 4 litres to 1kg grain is good.

 

[nzefactor]

Try more water. I think about 4 litres to 1kg grain is good.

If you've got the mash tun space then I'd give this a go first. 5kg into 12L sounds really low. Correct me if I'm wrong but even with a 3L sparge ~20L sounds on the conservative side for full(ish) volume BIAB?

Other steps you could try are a longer mash (90min instead of 60) and more/better lagging for the mash tun. Personally these two steps helped me go from mid 50s efficiency to 70s with BIAB.

 

[Kingy]

When I biab I use 37 litres of water for a 23 litre batch from memory it's around 7.4litres of water per kg of grain (no sparge). Efficiency is 73%

 

[poggor]

Well thanks for the tips. I made a second batch this afternoon- a Duvel clone.

This time I mashed 5kg of grain in 15L (3L/kg- the max my mash tun could deal with) I also mashed for 90min instead of 60 and added a litre of boiling water midway (temp was 65 at end of 90min from strike of 68).
Sparged with 2L of 77c water and put 15L in the kettle... hey presto: efficiency 71% as per beer alchemy.

... easy!

thanks

 

[Bribie G]

An OG of 1085 ain't Bohemian Pilsner, dat's Malt Liqou', bro homie, mah main man. :beerbang:

For "normal" strength beers with 12-15 L batches I'd only be looking at around two and a half to three kilos. Why are you brewing so strong?

 

[poggor]

Bribie- preboil gravity of 1.085 is for 12L boil. This would normally then be diluted to 18L in the recipe for an OG of 1.056 or so. which is Pils.

 

[Camo6]

From my understanding poggor, when you're trying to hit those higher OG's you're going to get a drop in efficiency. I tend to drop my efficiency in Beersmith 10% or so when doing bigger beers and I still find it a bit hit and miss at times.
It sounds to me like you need a bigger mash tun!

 

[rbtmc]

poggor, consider investing in a 40L Eletric urn kettle or a big-ass stock pot.

 

[spryzie]

You're a Big W pot person then?

Yeah, I can fit 5kg of grain just in mine too. But 4kg is better.

With your small pot, always fill it to the brim when mashing.

Also, I don't worry about mash temp much, I simply mash in at 50c, ramp to 60c for an hour (or less sometimes), and then ramp to 70c for an hour (or less sometimes). Then mash out and sparge.