Efficiency

[Netflyer]

I have a q about efficiency... grain efficiency vs. brewhouse efficiency...

I was reading somewhere that really 70% is all you can maximally get out of grain... not sure why if this is true we don't call that 100%...

That said, I found myself getting more than the target OG's so I told Beersmith and it said my brewhouse eff. was something crazy like 90% ... this was on a high gravity beer I made a while ago... and I read here all the time that we are very eff. many folks say they are getting over 70% anyway...

So my question is, can you really get more than 70% out of given grain? And if that is true is our brewhouse eff. not more a measure of if we got or did not get that 70%? That doesn't seem right either.

I ask this because I always seem to overshoot BUT when try to compensate with a lighter grain bill I always undershoot ;p, it's maddening and I don't need to become any madder...

I compensate by taking gravity readings during the boil and change the boil or the volume but I shouldn't have too

 

[Pappers_]

How far off is your original gravity from your targeted OG?

Just to understand your question: if you brew the same beer twice, you will get significantly different efficiencies? For example, you brew an APA, you get 90% efficiency. So you adjust your recipe for the APA and plug in 90% efficiency, but this time you get 70%. Is that what is happening?

 

[diS]

I think you are confused with theoretical maximum potential of malt which is in 70s% range. This maximum potential is reached when all sugars are dissolved and it is calculated by multiplying extract potential of malt with potential of sugar (since table sugar is completely soluble and its potential is 46 pppg).

BS calculates that efficiency as 100% (malt potential percentage of 46 ppg).
eg. if we mash 2-row malt which potential is 77%, maximum pppg would be around 36 (46 x 0.77 = 35,42), and 1 pound of grain in 1 gallon of water could result with OG 1.036 wort. But this is theoretically, and in real world OG will be lower since we cant extract all sugars from grain.
Try to make test recipe in BS and see how it changes OG based on changed efficiency.

Your efficiency shouldn't change during the boil since gravity is in relation with volume:
C1V1 = C2V2
where C is concentration and V is volume.
You can calculate eff. pre-boil and (if all readings are right and you didn't added extra sugar) it wont change after boil.
Doing math this way, you can measure OG pre-boil and calculate what you"ll get after boil, so there shouldn't be surprises.
Most important thing is to learn your system and set all parameters in BS correctly (pre-boil volume, boil off volume, brewhouse efficiency) and you"ll hit target OG close enough that you wont bother with it.

 

[Netflyer]

Yes, diS, that is what I am confusing or trying to understand but you explained it, beersmith considers the maximum extraction to be 100% eff...

And Pappers, I figured out what I did wrong I think was to assume that because my system could brew one beer at 80% eff. if I used another recipe that said its grain bill was for 70% eff. I would use beersmith to lower the grain bill to compensate for my extra 10%. The mistake I made was that the beer I was brewing was a MUCH lighter beer than the ones I normally brew and get high eff's on and my eff. was just not gonna be as high... so I cut down the grain and also the OG

Thanks guys for helpin!