Is brewtoad efficiency calc is off?

Brewing this recipe (BIAB style, 60 min mash no sparge but with 170F mashout) got me to 1.046 instead of the calculated 1.064.

Efficiency in Brewtoad was set to 60%. 1.046 means i go about 46% efficiency (according to Brewtoad).

Is is just me? I think I executed the recipe very well..

Amount Fermentable Maltster Use PPG Color
6.0 lb Pearl (UK) Any Mash 37 2 °L
3.0 lb Pale 2-Row (CA) Any Mash 36 1 °L
5.0 oz Crystal 60L (CA) Any Mash 34 60 °L
5.0 oz Carapils (DE) Any Boil 35 1 °L
Hops

Amount Hop Time Use Form AA
0.6 oz Columbus (US) 60 min First Wort Pellet 15.0%
0.3 oz Chinook (US) 15 min Boil Pellet 12.0%
0.3 oz Citra (US) 15 min Boil Pellet 13.7%
0.4 oz Chinook (US) 5 min Boil Pellet 12.0%
0.4 oz Citra (US) 5 min Boil Pellet 13.7%
0.6 oz Simcoe (US) 0 min Boil Pellet 13.0%
0.3 oz Chinook (US) 0 min Boil Pellet 12.0%
0.3 oz Citra (US) 0 min Boil Pellet 13.7%
1.0 oz Citra (US) 5 days Dry Hop Pellet 13.7%
0.5 oz Chinook (US) 5 days Dry Hop Pellet 12.0%
Yeasts

Name Lab/Product Attenuation
Safale US-05 Fermentis US-05 85.5%


Stats

Batch & Boil

Batch Size
3.3 gal
Boil Time
60 min
Properties

OG
1.064
FG
1.009
IBU
75
ABV
7.2%
Color
7 SRM
Balance
1.18 – Very Bitter

How much strike water did you use, what was your pre-boil volume, and what was your post-boil volume. Need those values to double check the efficiencies.

Brew on

Striked grains with 5.55 gal of water at 163 °F. Mashed at 155 °F for 60 min.

Mashed out. Drain the grain bag into the mash water to make 4.6 gal wort pre boil.

beauvafr said:

Striked grains with 5.55 gal of water at 163 °F. Mashed at 155 °F for 60 min.

Mashed out. Drain the grain bag into the mash water to make 4.6 gal wort pre boil.

Click to expand...

Ok, assuming that your pre-boil volume was measured at mash temp, then it's equivalent to 4.5 gal @ 68°F. You didn't state your actual post boil volume, so I assume you hit your recipe target of 3.3 gal @ 68°F. The results of the simulation are as follows:

• Your apparent grain absorption is 0.11 gal/lb. This is on the high side for BIAB. You can increase your efficiency by leaving less wort in the grain. This can be done by draining longer and/or squeezing the bag to extract more wort.
• Your mash and brewhouse efficiencies are both 45% (assumes all post-boil volume went into fermenter.)
• Your starch to sugar conversion efficiency is only 58% - 59%. This is really low! You should be getting at least 90%, and 95% or better is readily achievable.
• If you had achieved 95% conversion efficiency, your OG would have been 1.072, and your mash/brewhouse efficiency would have been 70% - 71%.

The difference between my mash efficiency (45%) and BrewToad's (46%) is probably due to slight differences in our assumed grain potentials. This amount of difference between calculations is acceptable, so your BrewToad efficiency is correct.

Your big issue is with conversion efficiency. It is likely that you have a very poor crush. Coarsely crushed grain takes longer to convert than finely crushed grain, so longer mash times can help with conversion if you can't crush finer. You may also need to do a better job of stirring during mash in. Dough balls are dry inside, and so the grain inside them will not convert at all. Make sure you stir well enough to eliminate all dough balls, even small ones. Also make sure to stir your mash well immediately prior to lifting the bag out of the wort.

Brew on

Thanks but Brewtoad was set to 60% not 46.

beauvafr said:

Thanks but Brewtoad was set to 60% not 46.

Click to expand...

The efficiency "set" in any brew calculator is what the program uses to make projections of things like OG based on a recipe, or how much grain you need to achieve a target OG. So, the projected 1.064 OG is based on assuming a 60% efficiency. 46% is what BrewToad determined your actual efficiency was after the fact. When I did independent calculations after the fact, I got 45%, which is pretty good agreement, given all the things that can add small errors to the calcs.

Brew on

I agree that the likely culprit is a crush that is far too coarse. Do you happen to have pictures from this batch or could you take some next brew? The other admittedly unlikely thought I have is that if your thermometer is not correctly calibrated, your mash temp could be significantly different than you think causing poor conversion.

MrHopScotch said:

I agree that the likely culprit is a crush that is far too coarse. Do you happen to have pictures from this batch or could you take some next brew? The other admittedly unlikely thought I have is that if your thermometer is not correctly calibrated, your mash temp could be significantly different than you think causing poor conversion.

Click to expand...

Yeah, incorrect temp is a possibility.

Brew on

doug293cz said:

46% is what BrewToad determined your actual efficiency was after the fact.
Brew on

Click to expand...

Nope. 46% is me changing the efficiency in Brewtoad to get 1.046 from the same qty of ingredients.

So Brewtoad was off : 60% - 46% = 14%.

Seems to me a huge difference even if I dont double crush and mash 90 min, assuming some people get 80% out of BIAB.

MrHopScotch said:

I agree that the likely culprit is a crush that is far too coarse. Do you happen to have pictures from this batch or could you take some next brew? The other admittedly unlikely thought I have is that if your thermometer is not correctly calibrated, your mash temp could be significantly different than you think causing poor conversion.

Click to expand...

I got the temp form 2 different thermometer. One from the kettle probe and another one digital, directly in the mash.

beauvafr said:

Nope. 46% is me changing the efficiency in Brewtoad to get 1.046 from the same qty of ingredients.

So Brewtoad was off : 60% - 46% = 14%.

Seems to me a huge difference even if I dont double crush and mash 90 min, assuming some people get 80% out of BIAB.

Click to expand...

You don't seem to understand what brewing software does. It only does well known calculations, using the inputs you give it (or the defaults if you don't provide explicit inputs.) You are responsible to tell BrewToad what typical efficiency your process achieves, so that BrewToad can use that value to make predictions. The software is not to blame if it isn't given appropriate inputs, or if the brewing process is not executed proficiently. If the inputs you provide don't match with how your process performs, then the calculations won't match the brewing results. This is what happened. Your process was deficient, and you didn't achieve anywhere near the efficiency (specifically conversion efficiency) that BrewToad was told to expect. If your conversion efficiency wasn't so bad, you could easily have achieved 70% efficiency. With a few other process clean ups you could achieve 76% efficiency with this grain bill and no-sparge BIAB.

Brew on

doug293cz said:

You don't seem to understand what brewing software does. It only does well known calculations, using the inputs you give it (or the defaults if you don't provide explicit inputs.) You are responsible to tell BrewToad what typical efficiency your process achieves, so that BrewToad can use that value to make predictions. The software is not to blame if it isn't given appropriate inputs, or if the brewing process is not executed proficiently. If the inputs you provide don't match with how your process performs, then the calculations won't match the brewing results. This is what happened. Your process was deficient, and you didn't achieve anywhere near the efficiency (specifically conversion efficiency) that BrewToad was told to expect. If your conversion efficiency wasn't so bad, you could easily have achieved 70% efficiency. With a few other process clean ups you could achieve 76% efficiency with this grain bill and no-sparge BIAB.

Brew on

Click to expand...

So you are basically saying brewtoad is right and I had 46% efficience for this brew?