Low mash efficiency - help?

[fbsf]

That's a point Dr. Mike - maybe I was expecting too much from a small volume. But don't BIABers mash with their full amount and only do a minimal sparge?

Maybe it's the malt, but I am thinking it might be more along the water/treatment lines, or that my filter is making the water too pure and removing a lot of the minerals.

I've tried both BIAB and Mashtun with manifold, doing from 2L/Kg up to 4L/Kg and still get the same result.

I might try some Tesco Ashbeck bottled water for my next brew (at worst it'll cost me around a fiver) just to see if it makes a difference... Have I seen somewhere that people add Gypsum to it or am I going mad?

 

[RobWalker]

well, i just mashed about 4.5kg grain, total volume of the mash was 28L so about 23-25L water. that got me 1.058 after mashing, and 1.068 after boiling, so you shouldn't be running into major issues water quantity wise with BIAB.

 

[fbsf]

In that case I think the first thing to eliminate is the water. This brew ended up ok (after the life saver that was the DME) with 13L @ 1.085.

 

[Dr Mike]

That's a point Dr. Mike - maybe I was expecting too much from a small volume. But don't BIABers mash with their full amount and only do a minimal sparge?

A similar logic applies to BIAB - When you lift the grain out of the wort, it will hold about 1L/Kg of wort even once drained. That wort will have sugar in, and with minimal sparging it won't find it's way into the boil. In a lower stength beer, the concentration of sugar in the wort will be less so you lose less with the grain and there are less kilos of grain. In a strong brew, the concentration of sugar in the 'lost' wort is higher and there is more of it.

I doubt if anyone, BIAB or 3 vessel is getting 75% efficiency on 1090 brews unless they go for a very big pre-boil volume with an extended boil time to concentrate it down

 

[RobWalker]

perhaps so dr mike (that sounds odd,) but what you've gotta remember is that the sparge essentially occurs in the main mash using BIAB. it's not a neglected step as such, but there is more room for the sugars to dissolve into the liquor, so what sparging achieves in the mash and sparge method of brewing isn't a neccessary step in BIAB - sparging isn't used because it isn't required, not because it's impossible. in fact, it's a different method of mashing altogether.

the only time you sparge with BIAB is with maxi biab, which is required for high gravity brews or lower gravity brews on a smaller system - again, out of neccessity. i'm not saying you're wrong at all mike, hahah - i wouldn't like to try a high gravity brew with BIAB.

 

[richardagutteridge]

: : I've also been having the same problem and have asked for help in a different section.

When I started AG 3 years ago I was getting the correct BHE of 70% following Wheeler's recipes, this has however dropped over the last few months to 65 then 60%. I buy all my grains from the same shop as I have always done, I buy the Pale Malt in 25K bags and never had a problem until the last few brews.

IMHO I think it has something to do with the MT not holding the heat and/or I'm not taking as much time over doughing in as I used to.


Ther last brew I made I had to rush as we had our grandaughter staying with us and I had to take her to school, as she got let down with her lift just as I was half way through doughing in.

Looking back through my notes some of my earlier brews were below the OG and these were when I was rushing the start, also I've been sparging a lot faster than I used to, so all in all I think that all or some of these may also apply to fbsf.

:drink: Richard G

 

[bunkerbrewer]

in fact, it's a different method of mashing altogether

Yep, I BIAB, have never sparged and average about 78% mash efficiency (including a brew with 66% mash efficiency). For what it's worth I'm averaging 0.5L/kg grain absorption rather than 1L/kg.

The biggest improvements I got to my efficiency were stirring the mash more often, and doing a final mashout to 78°C while stirring. I also mash for 90 mins.

Simply stirring the mash made the biggest difference :)

 

[Dr Mike]

...but there is more room for the sugars to dissolve into the liquor, so what sparging achieves in the mash...

This is true for normal strength beers but once you get up to high OG, say over 1080, a BIAB brew is going to be using a similar liquor to grist ratio as a 3 vessel brew (and said 3 vessel brew would have little space for sparge water in the boiler anyway.)

I'm not saying you can't get good efficiency with BIAB. The point I was trying to make is that, irrespective of whether it's BIAB or 3 vessel, efficiency declines as you go for higher OGs (My first AG worked out at 74% for a 1042 bitter. My second two were only 70% but at 1058. My 4th today was 73% at 1050). The OP is dissapointed about not getting 75% efficiency with a 1090 brew. No matter how good your technique, malt and water are, I'd say that is unattainable unless you're prepared to aim for a big pre-boil volume and boil it down for 3+ hours.

 

[fbsf]

Cheers for all the responses guys - that's certainly one to bear in mind. I think my conclusions are that my BIAB setup seems to work ok (and is less faffing than the 2FV tun I've used before), and that 60-65% efficiency on a 1080ish brew probably isn't that bad or far out. :

So all I'll do is to start at 73%, and drop 3% efficiency for each 10 points above 1.045 that I'm going for, and I *should* hit target!

I still think I'll try the Tesco Ashbeck next time just as a cheapish worth-a-try though.

Either that or keep a stock of DME in :lol:

 

[adomant]

Ph can't be emphasised enough, it is important for efficiency, hop utilisation, yeast health and microbe control. An old rule of thumb goes "6 in the liquor, 5 in the mash and 4 in the beer".

Use ams or any alkalinity reduction acid to regulate the mash. Calcium chloride flakes to regulate the mash to get the required ph.

It's worth noting that ph was first discovered in brewing