Why is my efficiency so low? - BIAB All grain

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DTimblin

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Hey guys, first post here and new brewer as well.

I've done 3 all grain BIAB brews now, two attempted Imperial IPAs and a Pale Ale.

For the first Imperial, I was aiming for 1.085 OG and I used a grain bill of 9.75 lbs, single ground, and was planning a 2.5 gallon into the fermenter batch. Got 2 gallons and 1.065 OG.

2nd Imperial was scaled up but about the same.

Pale Ale was shooting for 1.070, and this time it was a 5 gallon recipe. Double ground the grain and used 13 lbs. I ended up with only 3.5 gallons and almost hit the OG but added .5 lbs of dextrose as well.

All times I have taken the bag out, allowed it to drain, then placed it into a 1 gallon at 170 degrees 'sparge' which I have added back into the wort.

So, what am I doing wrong? And a sub question - how can get my volume calculated correctly to end up with the correct amount for my recipe?

Thanks for any help in advance!

-Dave
 

theseeker4

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Hey guys, first post here and new brewer as well.

I've done 3 all grain BIAB brews now, two attempted Imperial IPAs and a Pale Ale.

For the first Imperial, I was aiming for 1.085 OG and I used a grain bill of 9.75 lbs, single ground, and was planning a 2.5 gallon into the fermenter batch. Got 2 gallons and 1.065 OG.

2nd Imperial was scaled up but about the same.

Pale Ale was shooting for 1.070, and this time it was a 5 gallon recipe. Double ground the grain and used 13 lbs. I ended up with only 3.5 gallons and almost hit the OG but added .5 lbs of dextrose as well.

All times I have taken the bag out, allowed it to drain, then placed it into a 1 gallon at 170 degrees 'sparge' which I have added back into the wort.

So, what am I doing wrong? And a sub question - how can get my volume calculated correctly to end up with the correct amount for my recipe?

Thanks for any help in advance!

-Dave
Are you checking whether your conversion is complete with iodine? How well are your temperatures being monitored? Have you calibrated your thermometer?

If all these are fine, you would probably want to look at what your water chemistry is, as this can have an effect, sometimes substantial, on your efficiency.

I think the volume issue is mostly a matter of getting to know your "system." Once you do a few batches, you will have a better feel for boil-off rate, how much water is retained per pound of grain, etc.
 

BigDog007

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+1 on dialing in your system.

I initially verified my boil off rate as well as my cooling shrink ,etc... I use Beersmith 2 to get my calculated volumes, strike temp, etc... Once I had the actuals I put them into Beersmith for my equipment profile and volumes have been nearly dead on.

I brewed a batch this morning and realized my gap on my mill was much finer than I anticipated so I only single crushed and I got 76% efficiency, expected 1.051 SG but got 1.052 and volume was dead on pre-boil. I also use a RIMS for the mash and found that I had to do the auto-learn function to get it to reach temperature appropriately, also learned today that part of my problem of hitting mash temp was that I wasn't heating up the rims tube before mashing. This caused temp drop when I started mashing which was an issue.

Anyway - Keep at it, you will get there, record all of your volumes, etc... and learn from that, it's really helping me. Also - This forum is a kick ass resource to get lots of great info. I feel advanced compared to my Mr. Beer experience 4 months ago....

Brew On!
 
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DTimblin

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Thanks guys! I was less worried about the volume because as you guys said, I can just adjust for that.

Never tried iodine for the conversion being complete, might do that. I've just gone by sweetness of the wort.

Temp has fluctuated some during the mash, mostly going low. How do you guys keep from losing too much? Thermometer is accurate I believe, but worth checking again.
 

brewmesomewater

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Thanks guys! I was less worried about the volume because as you guys said, I can just adjust for that.

Never tried iodine for the conversion being complete, might do that. I've just gone by sweetness of the wort.

Temp has fluctuated some during the mash, mostly going low. How do you guys keep from losing too much? Thermometer is accurate I believe, but worth checking again.
As for the thermometer just boil some water, and you calibrate from the 212 differential.

Are you doing 60 minute mash times? if you have a hard time maintaining your temp, you may want to increase mash time to get a higher conversion.

With that being said, I did a 90 minute mash, let the bag drag, squeezed the life out of the bag, sparged 160 degree water til I met pre wort volume and decided to squeeze the bag again. The hefeweizen was projected to have a 1.056 OG and I hit 1.070! Couldn't believe it.
 

wilserbrewer

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Who is crushing your grain? I suggest posting a clear close up pic of your crushed grain. Are there many uncrushed kernels if you examine it very closely? You can even inspect the spent grain for uncrushed kernels, the goal is none to few for a good crush!

Regarding volumes, I suggest making a measuring stick to measure actual volumes in your kettle as you progress throughout the brew session....if short sparge more, and if over volume boil more and time late hops to flameout.

Don't sweat it, you'll get there, it's not that difficult.
 

Gavin C

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With all grain brewing you need to start out with the end goal in mind. A pre-determined volume at a planned specific gravity in to the FV. Getting one right without the other is doable but its best to target both concurrently if accuracy is what you seek.

I see from your post that you are brewing BIG beers. These require even more accuracy in ones setup as errors tend to be magnified. Trying to get your system's fundamentals well and truly understood with smaller beers might be worth considering.

The more precise you can be with your measures the better
Volume
Initial water volume added (strike water) and sparge water if you do one
wort volume lost to
  • grain absorbtion
  • trub loss
  • boil off

There are lots of ways to measure volume in ones kettle.
An etched kettle is oneVolume Marks.jpg

Fermenter losses are also noted but from a planning point of view less important. I prpare for 5.5 gallons to the FV and 5 gallons to the keg.

Weight of grain
Any decent scale should suffice

Temeprature of the mash and strike water to achieve it

This is importatnt in getting the most from your grains and in achieving what you want in terms of body, and attenuation.
Get a decent thermometer.
Check the calibration on it in crushed ice

Thermapen.jpg

Grain crush is important. With BIAB there is no worry about a stuck sparge so use that to your benefit with a fine crush of the grains.

My CrushGrain 2.jpg

There are some great online calculators available for calculations of volumes. @Pricelessbrewing has a good one. (It's in his signature). Brewersfriend is also good as is Beersmith.

These are the big factors in efficiency and accuracy. However the fun doesn't stop there.

Water chemistry and mash pH can be explored. A city report or a Ward Labs report are useful information. I would't worry about that till I had my volumes, weights, temperature control and crush down pat.

A pH test with a good meterSample.jpgpH reading.jpg

You can insulate the pot during the mash with a coat or blankets or some insulating material. All work well. This will help get a more stable and uniform mash temperature.

Insulated MashInsulated Mash.jpg

It is important at least initially to make sure you are fully converting the starches in the mash to sugars. Verify this with an iodine test. If it turns blue there is starch present. You need to mash longer. With a fine crush this happens fast though.

A conversion test on a mash sample.Conversion test.jpg

For more tips and ideas you might want to check out my methods in the thread below. These and more are covered. All grain is a lot of fun. not everything I do would be deemed important by many a brewer. I do it this way because I enjoy the planning and process a great deal. Find your path and your beer and taste buds will be rewarded.
 
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DTimblin

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Wow that's a lot of helpful info thanks again!

Regarding the grain crush, my LHB has their grinder available for use by customers, so I sent the grain through twice and felt pretty good about the results.

This thread is definitely going to be a great resource to reference for next brew day
 

Gavin C

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Glad to help.

Regarding calibration of a thermometer. A previous poster mentioned doing this in boiling water. As per the Thermoworks' instructions on their devices a better way to calibrate thermometers is in crushed ice with minimal water to fill the voids. Boiling temperature varies more with altitude and is more prone to slight variation owing to the nature of boiling water.

It won't matter a great deal but if you are going to the trouble to calibrate a device, best to do it the more optimal way in my view.

As an example. I had been using a Polder Thermometer with a probe I would place in the mash. This reads 100C in boiling water but "Lo" in iced water. Now that I have a Thermapen I found that the Polder to be reading lower than the correctly calibrated Thermapen at mash temperatures by 2F.

It is still a good thermometer just not as accurate as I wanted. The crushed ice test shows this.
 

C-Rider

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Buy a Wilser bag and grind your grain to flour in a blender. You can do 10 lbs in about 15 minutes doing about 2 cups at a time. That's what I do for my 2 gallon batches and get 78-80% eff.
 

Magnus314

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None of those seem like enough water for that much grain.

The first thing I'd try is just plain using more water in the mash and the sparge both, and adjust your boil off if necessary, especially for those higher gravity beers.

There's a reason why those kinds of beers get longer boils- the extra water helps the efficiencies, and the extra long boil maxes out the hops!
 

Psylocide

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I count on about 1 gallon lost to the grains (in a 5.5 gal batch - ~10-12 lbs grain) and 1.5 gallon boil off, gets me close enough. I'm getting ~75% mash efficiency pretty standard right now. Fine grind in a blender using paint strainer bags and stirring like crazy during mash in and sparge.

I have no doubt it will improve as I improve my process. But I'm very happy with 75% for the time being.
 
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