BHE all over the place

[specialkayme]

The last 3 brews I did (all the same equipment) had very wide ranging BHE. For example (all SG's listed are OG's and removes the honey I added to each):

1. Belgian Strong Ale - 15 lb. 2 oz grain bill - SG 1.076 - BHE 74.69%
2. Cascade Pale Ale - 10.5 lb. grain bill - SG 1.061 - BHE 86.36%
3. Milk Stout - 6.1875 lb. grain bill - SG 1.061 - BHE 79.93%
4. Helles Lager - 9.375 lb. grain bill - SG 1.055 - BHE 91%

The milk stout was a 3 gal batch. The rest were 5 gal batches, but as I'm dialing in the grain absorption and boil off rates for my system, I've had between 5 and 5.75 gallons going into the primary for each of those 3 brews above. Dancing back and forth between mid to high 70's and low 90's is making it difficult for me to make an accurate guess on grain bill going into the mash. I don't really care where it lands, as long as it's consistent and I can estimate it (and low 90's seems wrong).

I didn't do anything different between these brews (process wise at least). Is this type of BHE swing normal, or am I doing something off?

 

[RPh_Guy]

Posting mainly to subscribe.

From my understanding many factors may affect efficiency, including (but not limited to):
crush size
mash time, technique
sparge technique
sparge water temperature
mash temp
mash pH
boil time
equipment losses

Variability in these factors may partly explain the variable results.

Also consider possible measurement error. Are you sampling the "OG" at the hydrometer calibration temperature?

You're removing all added sugars from the calculations?

Cheers, hope the beers are good regardless!

 

[specialkayme]

From my understanding many factors may affect efficiency, including (but not limited to):
crush size
mash time, technique
sparge technique
sparge water temperature
mash temp
mash pH
boil time
equipment losses

Variability in these factors may partly explain the variable results.

Now that you mention it, the first one was run through the mill once, the rest were run through the mill twice. Which impacted crush size. But other than that, the rest were all done the same.

Also consider possible measurement error. Are you sampling the "OG" at the hydrometer calibration temperature?

All adjusted for temp.

You're removing all added sugars from the calculations?

The only thing I'm removing is the honey I added. No other sugars were added (or subtracted).

Variations on batch to batch may result in a 5%+/- swing, but I didn't expect that much of a swing.

 

[RM-MN]

[QUOTE="specialkayme, post: 8374573, member: 212722"]Now that you mention it, the first one was run through the mill once, the rest were run through the mill twice. Which impacted crush size. But other than that, the rest were all done the same.



All adjusted for temp.



The only thing I'm removing is the honey I added. No other sugars were added (or subtracted).

Variations on batch to batch may result in a 5%+/- swing, but I didn't expect that much of a swing.[/QUOTE]

As you noticed, the crush of the grain is the biggest factor in brewhouse efficiency. The other variations are much closer, perhaps due partially to measurement differences in the amount of wort into the fermenter and any wort left behind such as a whirlpool to limit the amount of trub into the fermenter.

 

[FunkedOut]

Dismiss the 1st one due to the different crush.

Keep track of the smaller batch separately as the BHE should be lower for smaller batches.

That leaves you with 2 batches; 86% & 91%.
Aim for 87%-88% next time and keep building a trend.

I’d suggest tracking your mash efficiency as well. That’s a more direct number for you to predict grain bills. It removes some variables compared to BHE.