I'm wondering if anyone else is doing this? I mash in a cooler and use a mash out. My method is to add the strike water aiming for a 152F mash. After 40 mins or so I lift and drain the bag. I lower the bag back in and add the rest of the water aiming for 168F mash out for 10 mins. The first running can now be put in my kettle. How would I calculate my conversion efficiency? Not just mash since I do not lauter, but overall efficiency? Brewers friend calculator has Conversion and when I plug my numbers in it gives me over 95%. It also has Pre Boil that looks more like overall conversion efficiency and for that I get a more likely 75%.
My Method and Efficiency
- Thread starter HazyBeer
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
madscientist451
Well-Known Member
I started with BIAB on the stove, then switched to BIAB in a cooler, now back to BIAB on the stove.
So what is the purpose of pulling the bag out and letting it drain? Why not just drain your first runnings to the kettle add your sparge water and then drain that? I also usually do a 60+ minute mash because I'm not in a hurry, but I have done shorter mashes.
So how do you calculate efficiency?
Just use the online calculator that you already know about.
So what is the purpose of pulling the bag out and letting it drain? Why not just drain your first runnings to the kettle add your sparge water and then drain that? I also usually do a 60+ minute mash because I'm not in a hurry, but I have done shorter mashes.
So how do you calculate efficiency?
Just use the online calculator that you already know about.
Unless you are doing a slow fly sparge and do not already have full conversion of starch to sugars you do not need a mash out.
I MIAB and batch sparge. After mashing (usually 60 min) I vorlauf twice my expected first runnings volume, then drain the first runnings, collect a sample, and measure the amount collected. I subtract that amount from my desired pre boil volume, divide by two and sparge with two equal infusions. I plug the SG of the 1st sample into a conversion calculator if I want to know my efficiency. I usually skip that step for most brews because I can‘t recall ever getting a number <97%.
Conversion efficiency is defined as the amount of extract (mostly sugars) created in the mash divided by the maximum potential extract of the grain bill. 100% conversion efficiency is possible.
Mash efficiency (pre-boil efficiency in Brewers Friend) is defined as the amount of extract collected in the boil kettle divided by the maximum potential extract of the grain bill.
Lauter efficiency is defined as the amount of extract collected in the BK divided by the amount of extract created in the mash. Lauter efficiency is always less than 1 (or 100%) because you cannot get all of the extract out of the spent grains during the lauter.
Mash efficiency also equals conversion efficiency times lauter efficiency, so mash efficiency is always less than conversion efficiency.
Lautering is defined as separating wort (or more specifically extract) from the spent grains. Thus you are lautering. What you are not doing is sparging. Sparging is rinsing the spent grains either after (batch sparging) or during (fly sparging) the initial wort run-off from the mash. Sparging is an optional part of lautering. Sparging will always increase your lauter efficiency, and thus mash efficiency as well, all else being equal (grain bill, pre-boil volume, etc.) How much sparging improves lauter efficiency depends on the details of your sparge process.
Brew on
That would be my question. Letting the bag drain then just putting it back into the wort seems like it would just undo any advancements of draining the bag. I would expect more extraction of sugars when sparging with water, vs adding water to your existing wort.
I usually do a full volume mash, but when I do sparge I just hold back some water (around 2 gallons) for a dunk sparge in a bucket (similar to a batch sparge). Adding in the sparge step boosts my efficiency about 5%, but adds more work and complexity. I have sparged with both heated and tap-temperate water and did not notice a big difference.
Brewersfriend lists Conversion and Pre-Boil on their site. Does their Conversion mean Mash efficiency? And Pre-Boil their overall conversion combining Mash and Lauter? I ask becuase in BIAB we don't lauter.Conversion efficiency is defined as the amount of extract (mostly sugars) created in the mash divided by the maximum potential extract of the grain bill. 100% conversion efficiency is possible.
Mash efficiency (pre-boil efficiency in Brewers Friend) is defined as the amount of extract collected in the boil kettle divided by the maximum potential extract of the grain bill.
Lauter efficiency is defined as the amount of extract collected in the BK divided by the amount of extract created in the mash. Lauter efficiency is always less than 1 (or 100%) because you cannot get all of the extract out of the spent grains during the lauter.
Mash efficiency also equals conversion efficiency times lauter efficiency, so mash efficiency is always less than conversion efficiency.
Lautering is defined as separating wort (or more specifically extract) from the spent grains. Thus you are lautering. What you are not doing is sparging. Sparging is rinsing the spent grains either after (batch sparging) or during (fly sparging) the initial wort run-off from the mash. Sparging is an optional part of lautering. Sparging will always increase your lauter efficiency, and thus mash efficiency as well, all else being equal (grain bill, pre-boil volume, etc.) How much sparging improves lauter efficiency depends on the details of your sparge process.
Brew on
My conversion per Brewersfriend went up 20% by adding the mash out. In some cases to over 100%.
I lift the bag to let the first runnings drain faster from the cooler. Then bag goes back in and I add more water to bring the temp to 168 for ten mins and then get my second runnings.
My statement stands. You did not have full conversion and by heating the mash to mash out temps you accelerated the alpha enzyme activity. Now think about why you did not have full conversion before you did a mash out and correct the cause. The normal reason is a poor crush coupled with a shorter mash period than necessary.
If you got over 100% mash conversion, check your math. Since that is an impossible condition there must be an error somewhere.
Since you lift the bag and let the runnings drain into your boil kettle, the water you add when you put the bag back in to do a mash out is in fact a dunk sparge. In itself this will increase the gravity as you rinse more sugars off the bag of grains and if you didn't squeeze the bag to get all the possible first runnings this dunk sparge may be responsible for the extra efficiency without the mash out.
Your questions indicate that you did not understand my post that you quoted. These questions were all answered in the post. Please reread the post until you understand what I said. If you are confused by the term "extract" just think "sugar" wherever I say extract. Extract is more than just sugar (it includes small amounts of proteins, lipids, etc.) but thinking in terms of sugar (which includes dextrins) may make understanding easier.
Based on the description in your first post, I did not think you were sparging (because your process description was incomplete.) But, in a subsequent post, you describe your process as including a batch sparge (as @RM-MN noted.)
Brew on
Last edited:
More likely measurement errors (volumes, weights, SGs), or data entry error(s) since OP is using an on-line calculator.
Brew on
Ok so now I know what to call it. I dunk sparge. And I do squeeze.
Actually over 100% is possible since the comparison is too a Congress mash. So if your conversion is better then a Congress mash you go above 100%. It does not mean that you got over 100% of the available sugars as that would be impossible.
My real question is on Brewersfriend what is the difference between "Conversion" and "Pre-Boil" in their efficiency calculator?
It is possible, but a Congress Mash is a several hour long process with multiple temperature steps using a very finely ground grain. In a homebrew setting you can get close as far as conversion goes, but if you are at 100% or above, it is very likely an issue with measuring.
I don't worry about efficiency before Pre-Boil. I am not quite sure how to measure "Conversion efficiency" or if it really applies to BIAB. @doug293cz gave a definition of Pre-Boil above. This is based on having accurate volume and gravity measurements of the amount of wort that you got out of the mash process (including any sparge or mashout steps). I am never 100% sure what temp the volume should be measured for BeerSmith, but I just measure the volume when I get close to a boil.
I mostly do full volume mash with BIAB and I tune my Mash Efficiency at 78%. That seems in line with the 75% that you have measured.
I should have just re-read Palmer instead of using an online calculator. My last batch yielded 7G of wort at 1.068 using 17lbs of malt. (7 x 68)/17 gives me 28 ppm. Using 16 lbs of 2 row at max of 37 ppm and 1 lbs of Oats at 32 ppm my mash efficiency is 76%. Not sure what Brewsfriend is measuring when you select "Conversion".
I would rate getting more than 100% conversion in a homebrew setting a practical impossibility.
Brew on
Maybe this will help:
Source: Brewer's Friend
Simplistically, Conversion Efficiency is the percentage of starch in the grain that is converted to sugar in the mash. It's actually a bit more complicated as it's based on specific gravity, and everything soluble (sugars, dextrins, proteins, lipids) that comes out of the grain into the wort adds to the SG. All the soluble stuff that comes from the grain in the mash is defined as extract, which is ~90% carbohydrates (sugars, dextrins, soluble starches.)
-----------------------------------------------------------------------------------------------------------
The rest of this post is not about the definition of conversion efficiency, but rather about how percent extract potential is related to SG potential.
When you mash, some fraction of the grain is converted to soluble extract, and maltsters put this on their datasheets as a percentage. This percentage is called the extract potential. The value is based on doing a test mash (specifically a "Congress mash") done with a very fine grind, and the grain weight is based on the fully dried weight of the grain (0% moisture content.) So, what is listed on the datasheet is Fine Grind Dry Basis (FGDB) Extract Potential. Base grains typically have a FGDB potential near 80%.
When potentials are listed in SG format (e.g. 1.037) this is determined by the SG of the wort created (at 100% conversion) when one pound of grain is mashed with enough water to create one gallon of wort. Note that the mash water volume is less than 1 gallon, as some of the final wort volume is due to the extract dissolved in the wort.
If you dissolve table sugar (sucrose) in water, 100% of the sugar dissolves, so sucrose has an extract potential of 100%. If you dissolve one pound of sucrose in 0.954 gal of water you will get 1.000 gal of sugar solution (wort) at an SG of 1.0462, or 46.2 pts/lb. Thus 46.2 pts/lb is used to represent 100% FGDB extract potential. To determine the pts/lb extract potential of a grain, you multiply the percentage extract potential by 46.2. Thus if a grain has a FGDB extract potential of 80%, then the pts/lb is:
0.8 * 46.2 = 36.96 [which rounds to 37]
Therefore, 80% extract potential is an SG potential of 1.037.Brew on
Similar threads
