Efficiency and adjuncts

Should I expect lower efficiency when I’m using adjuncts?

This is the second brew where I’ve come out significantly lower.  Today I used 4 lbs. of 2-row and 2.75 lbs of instant rice.

I came out about 15 pts lower than I expected. About 50% efficiency rather than the 75% I usually get.

A month or so ago, I used Munich as my base in a stout I’ve brewed many times.  I came out at least 10 pts low.  I blamed it at the time on the Munich, as I’ve hit my OG before using 2-row and/or Pilsner.

I typically mash 5 lbs or so in a grain bag and the rest of the fermentables come from DME.

I don’t experience a lower efficiency when I’m using adjuncts.  As I sit here and type I’m sipping on a CAP I made with 20% flaked corn and I ended up with about 84% efficiency on this one (I did use some rice hulls).

Could it be lautering efficiency?  That might explain the rice.  Not sure why the munich would cause problems since it’s really more of a base malt, not an adjunct.

It was Munich with a bunch of flaked barley and oats.  I believe it has lower diastatic power than 2-row.

My second batch today was spot on and didn’t have any adjuncts.

You want the weighted average of the malt and adjuncts to be probably >40 for insurance.  It will convert around 35 -40 Lintner if all goes well.

If you used Munich I it is around 40 lintner.  If you used 6 lbs of Munich and 2 lbs of adjuncts you will have (240+0)/(6+2)=30 as the weighted average.  That might have some problems.

This is why for adjunct lagers the breweries use NA 2-row which is in the 140-160 range or 6 row at 160 lintner.  Those are pretty “hot” as far as enzymes and will convert easily.

The ratio was nowhere near that positive, and it was dark munich.  All I had at the time, and it was time to brew.

It does sound like that might have been Joe’s problem, but FWIW when I get light Munich it’s ~80-120°L.

From which malster?

Weyermann (~80) and Cargill (~120). I think I may have had one lot from Weyermann that was around 60-70, but I’m not sure.

OK, many places have Weyermann Munich I in the 40-50 Lintner range  For example:
http://www.midwestsupplies.com/homebrewing-ingredients/grains/light-munich-weyermannr.html

Can you share data?

Sorry, no. I don’t have a lot analysis around and we switched almost a year back. It could just be that my memory’s faulty. OTOH, that page also has it at 6 SRM, and I know for sure that what we got was 7-8 SRM. So maybe Midwest is worked from an old analysis too.

Just a pound of American 2-row, 6-row or even wheat can make a big difference.

I can see that the lots can have different values.  The analysis sheets would tell the true numbers.