Very low efficiency..not sure why!

[Rento]

I’m looking for some advice, I BIAB and usually get fairly good efficiency of between 70 and 80%. I’d did a Hefe clone the other night and only got 60% which is rather low. The recipe was:

1.8kg golden promise
2kg wheat malt
130g Munich malt.

I mashed at around 67c and as I don’t take a pre boil gravity I only have the post boil which is 1035 For 21l after an hour boil. My process is the same as usual, mash with 24l of water, drain/squeeze grain bag, then sparge with about 4l with a hot kettle over the grains to get the volume set for the boil.

Any ideas what’s happened?

Thanks

R

 

[foxy]

I’m looking for some advice, I BIAB and usually get fairly good efficiency of between 70 and 80%. I’d did a Hefe clone the other night and only got 60% which is rather low. The recipe was:

1.8kg golden promise
2kg wheat malt
130g Munich malt.

I mashed at around 67c and as I don’t take a pre boil gravity I only have the post boil which is 1035 For 21l after an hour boil. My process is the same as usual, mash with 24l of water, drain/squeeze grain bag, then sparge with about 4l with a hot kettle over the grains to get the volume set for the boil.

Any ideas what’s happened?

Thanks

R

When you say mashed at around 67 are you thinking the 67 isn't accurate?

 

[obscure]

It could be completetly unrelated but I always find I get lower efficiency when I use high levels of wheat (50% or more),

 

[Hazelwood Brewery]

Your water may be a contributing factor, the balance of salts and minerals, and the mash pH can affect conversion.

The milling of the grain might also be a factor. If you buy grain already milled then it’s possible you got a more coarsely milled batch? This could happen for example if the supplier was asked to supply coarsely milled grain for one customer and they forgot to reset the gap before milling grain for other customers.

For smaller differences it might even be different grain suppliers. For example Munich from BestMalz has an extract potential of 35 points per gallon where Weyermann’s is 38. I doubt this is the story in your case because the difference is quite high.

 

[Rento]

The grain is from my usual source and fine milled, although it didn’t look as fine as usual. I was wondering (as mentioned if it was related to using wheat and the mash temp as it’s my first time?

 

[Rento]

it dropped to 65 half way through So I heated up again to 68 which dropped back to 67.

When you say mashed at around 67 are you thinking the 67 isn't accurate?

 

[Hazelwood Brewery]

The grain is from my usual source and fine milled, although it didn’t look as fine as usual. I was wondering (as mentioned if it was related to using wheat and the mash temp as it’s my first time?

If it was malted wheat it should be fine because malted wheat has good diastatic power. If it was unmalted then that’s an entirely different story.

 

[foxbat]

Probably the crush. Wheat is huskless and the grains are harder and smaller than barley. If I were crushing it myself I'd probably put it through on its own once then maybe again with the rest of the grains.

 

[RoomWithABrew]

For wheat I always mill separately and with a finer setting as smaller grain and no husk.
Mash also is thicker due to lack of husk and so flow / mix not as good. Mash longer can help, use rice hulls or glucanase. As above if raw wheat you are also lower on enzymes so more time. Overnight mash can help. Testing your wort at the end of mash also indicates an issue.

 

[foxy]

it dropped to 65 half way through So I heated up again to 68 which dropped back to 67.

It isn't the temperature it dropped to, its the temperature that firstly you doughed in at, and secondly the temperature you mashed at. The higher the temperature the lower the efficiency, doughing in on the higher side destroys the enzymes.

 

[Rento]

I doughed in at 69 which is about normal as I loose 2 degrees and that brought the temp down to 67 for the mash. So should I have doughed in at a lower temp? Then my mash temp would have been too low?

I’m confused?

 

[Davvy]

Hello Rento,
I am a BIAB brewer and yes I have had exactly the same results in a wheat beer with roughly similar % components to yourself. I usually try to hit 1.050 -1.060 O.G. for all of my beer, bu this one was around 1.045 and particularly thin.
So my singular assumption was that wheat malt was was the cause.
So....never did it again, once bitten as they say.....

 

[foxy]

I fail to see why wheat malt would be a cause the diastatic power is higher than two row pale malt.
https://byo.com/article/understanding-enzymes-homebrew-science/

 

[Crappyfish]

Just done a wheat beer with Maris Otter 3Kg and Wheat malt the wheat weighed in at 1.6kg done calculations came out at 79% efficency also had a bit of Munich malt 0.1 Kg in it. I did it in a 3 in 1 and for first time I added bit at a time to the hot water and stirred it about 3 or 4 times and this is the highest efficiency I have achieved. The advice about adding a bit at a time came from this forum. I used to just dump the basket in with the grain in it. Thanks everyone best bit of advice yet was put grain in bit at a time. Also left the sparge plate off whilst the grain was in. 23l brew mashed at 67