Mass efficiency problem with big beer

[PierreLo]

Hi guys,

I have recently brewed to big beer: One double IPA and one wheatwine.
I usually achieve a 80% mash efficiency. I don’t know why but for these 2 beers my mash efficiency dropped to 60%.
I have changed nothing to my process :
- I mill my grains with a double roller monster mill. My gap is set at 0.61 mm which is fairly narrow.
- I have a tree vessels system with one kettle and two coolers.
- I continuously sparge over a long period of time like 45 minutes.
- I don’t experience stuck sparge.

I’m wondering if its my mash tun (Igloo cooler) that have difficulty to handle too much grain.
Any clue why my mash efficiency get so low?

 

[DBhomebrew]

Your two recent big beers had the same pre-boil volume as your typical smaller beers? Larger grain bill, constant pre-boil volume?

Totally normal. A matter of more water lost to grain absorption. The wheat can hold on to even more water.

 

[balrog]

See for instance, @doug293cz post here.

 

[SrLobaugh]

Was you mash temp consistent, and were the grains fresh. Next time try running a parti-gyle to see if you left and fermentables behind, you could be getting a bonus beer.

 

[Dland]

It is normal to get lower efficiency if grain bill exceeds optimal capacity of ones rig & process.

I know my efficiency begins to drop if I brew with more than 22# of grist. I'm sure that number will vary depending on specifics such as equipment and sprarging technique.

 

[TheMadKing]

It is normal to get lower efficiency if grain bill exceeds optimal capacity of ones rig & process.

I know my efficiency begins to drop if I brew with more than 22# of grist. I'm sure that number will vary depending on specifics such as equipment and sprarging technique.

Its actually not a function of the system at all. It's a function of grain bill to preboil volume.

The larger a grain bill for a given preboil volume, the lower efficiency will be. So if you do a 60 minute boil and your preboil volume is 7 gallons, you will have much worse efficiency with 18lbs of grist than you will with 9lb of grist.

The solution is to extend your boil and thereby increase your preboil volume, which allows you to sparge more.

 

[Dland]

Its actually not a function of the system at all. It's a function of grain bill to preboil volume.

The larger a grain bill for a given preboil volume, the lower efficiency will be. So if you do a 60 minute boil and your preboil volume is 7 gallons, you will have much worse efficiency with 18lbs of grist than you will with 9lb of grist.

The solution is to extend your boil and thereby increase your preboil volume, which allows you to sparge more.

Yes, but capacity of system dictates how much pre boil volume one can realistically achieve.

 

[Holden Caulfield]

It's a function of grain bill to preboil volume.

^, below is a chart with data demonstrating the relationship of grain weight to preboil volume. 80% to 60% is quite large, so other factors may be at play, but in general, you should always expect a drop off in efficiency when making big beers. Here is a link to the article...

https://beerandwinejournal.com/estimating-ee-gravity/
One approach to help ensure you hit your OG when making big beers is to use a lower than expected efficiency % and then pour off any extra sugar points collected, if needed. Just add water back to hit your preboil volume. It may cost a few bucks more per batch, but it ensures you hits your beer vision almost every time.

 

[PierreLo]

thanks for the info.
I did suspect that the grain bill weight would affect my efficiency, but I haven’t never read anything on that subject.
happy to know that this is the case and it’s not related to my technique or system.

for my last batch, I did boil for a longer time and end up with a 3.5 gallon batch instead of 5. next time I will just dial my efficiency ratio in my setting based on your graph.

 

[TheMadKing]

Yes, but capacity of system dictates how much pre boil volume one can realistically achieve.

True enough but if your preboil volume is the limiting factor in your system and not your mash volume, it may be time for a kettle upgrade

 

[balrog]

it may be time for a kettle upgrade

This is a hobby forum.

It's always time for a kettle upgrade.

 

[DBhomebrew]

True enough but if your preboil volume is the limiting factor in your system and not your mash volume, it may be time for a kettle upgrade

I've no idea what you're talking about.