Conversion efficiency advice needed!

Discussion in 'General Brewing Discussions' started by Michael_biab, Sep 23, 2021.

  1. Michael_biab

    Michael_biab Member

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    Hi there!

    I've been brewing all grain BIAB for 3 or so years now, about 27 batches documented in Brewer's Friend. I'm looking at my efficiency numbers (conversion, but also brew house) and they are all over the board.

    They range from a low of 49% to a high of 88% with an average of 65. The brew house efficiency ranges from a low of 48 to a high of 83 with an average around 62. But they vary a lot in no kind of systematic way I can see.

    I know these both can vary a lot based on process and gravity, with coarser crushes and higher gravity reducing the efficiency and finer crushed and lower gravity increasing the efficiency.

    Recipe wise, I am brewing exclusively ales (pale, IPA, bitter, mild, porter, stouts, double IPA and one barleywine). I don't see much trend with the brew house efficiency or conversion efficiency across styles.

    Process wise, I typically use pre-milled grain from MoreBeer. I typically gently squeeze the bag and let drip for 15 minutes. I do not adjust pH for a couple of reasons, mostly due to challenges I've read about when it comes to measuring accurately with pH strips or meters, and the challenges of successfully adjusting with acids. My water is relatively soft and I usually add 1-2 tsp gypsum. I've used the same types of kits for most of these, and always the same equipment (15 gallon mash kettle with the same municipal water).

    While my beer has not been negatively affected with regard to taste, my concern is more about trying to be accurate from a planning perspective.

    A lot of times I end up adding a few extra pounds of grain given that a lot of the kits I'm using from More Beer assume 70-75 percent conversion and I'm achieving lower than that. I also tried crushing the grain finer on a couple of batches but that does involve additional time/effort especially since I only have a manual Mill and don't want to add complexity and cost to my process if possible by buying an upgraded or motorized mill. I didn't document which I crushed finer unfortunately but I don't think it was phenomenally higher conversion.

    Any thoughts on how to better dial in efficiency so I can better plan my batches? Thanks in advance!
     
  2. Minbari

    Minbari Well-Known Member

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    My opinion. Crush and ph effect it the most. Get a ph meter. They are like$25 on Amazon.

    I make sure my ph is in the 5.2 area 10 into mashing.

    Also, get some iodine. 1 drop of wort into 1 drop of iodine on a white plate will tell you if your starches are converted. Sometimes you just need another 15-20 minutes.

    I routinely get 78-82% mash eff
     
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  3. Megary

    Megary Well-Known Member

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    Agree with @Minbari and I will double down on the importance of crush. There is no way to know how consistent the crush is that you are getting from MoreBeer. It’s probably ok for the typical lauter/sparge brewer, but not necessarily dialed in for BIAB, which usually benefits from a finer crush. If More Beer has a “double crush” option I would choose that, but if you really want consistency, you would be best served by getting a nice mill and crushing your own grain.

    Good luck.
     
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  4. Semper Sitientem

    Semper Sitientem Well-Known Member

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    +2 on the mill. I believe taking control of this part of the brewing process is important. I BIAB as well. My LHBS mills at 0.040. I mill at 0.025, directly into the bag which is in a food safe bucket. Easy to store and transport, as I usually mill the day before, and easy to transfer into my brew kettle. I use a drill with a 3/8” chuck to power the mill. For me a mill motor wasn’t a consideration as it’s a single use tool and only used 2-3 minutes for each batch.
    Cheers
     
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  5. HighVoltageMan!

    HighVoltageMan! Well-Known Member

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    The crush may have some bearing, but consistency is what your battling. In most home brewing situations, the amount of grain in the mash will effect the mash conversion rate dramatically. The more grain, the conversion rate drops. You need to get one beer style, using the same grain several times in a row. Track your mash efficiency only, brewery efficiency is depended on way too many factors and will change depending on the amount of hops used, spillage, etc.

    Document everything. Get a brewing sheet. track pH, crush, liquor to grain ratio, temperatures, water volumes, salt additions, brand of grain, type of grain, etc. As you track these parameters you hopefully will see patterns and possible reasons for the swing in conversion rates. Every batch, type and brand of grain will have it's own conversion rates and it will fluctuate +/- 5% or so. But it is possible to stay within this range once you get it figured out.

    Here is a brewing sheet I use. I have modified it many times to document what I need to track. Use it if you like, it may or may not work for you:

    https://docs.google.com/spreadsheet...y=0-ZPVVamEcAmsuD0Smey35Pw&rtpof=true&sd=true
     
  6. Donoroto

    Donoroto Well-Known Member

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    Don't fear adding a couple milliliters of lactic or phosphoric acid to your starting water. The water calculator here on Brewer's Friend comes pretty close, but it assumes you know what you water's starting profile is.

    I can't say that it'll change your efficiency.

    Returning to the original concern, the post immediately above is good advice.
     
  7. Mark Farrall

    Mark Farrall Well-Known Member

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    I noticed my biggest improvement in consistency and efficiency when I bought my own mill (BIAB brewer). That was after a bunch of other small improvements and a bunch of batches under my belt, so I may be attributing multiple improvements to the one change.

    I used to adjust pH, but I've got lazy recently and haven't noticed a difference to efficiency. Though I have very, very good water here, very close to RO, so that gives me a lot of wiggle room before pH really hits my efficiency on most beers. Planning to get the pH meter out again soon to start playing with pH pre and post boil. I didn't have any problems with correct readings once I understood that it needed calibration every time I used it.

    I think it's as much about being comfortable with your process so that you're doing things as close to the same way as possible. And that comes with multiple brews. And comfortable really means, comfortable that you're hitting the right temp, that you're measuring the gravity as well as you can, that you're putting in the right amount of water, etc.
     
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  8. Michael_biab

    Michael_biab Member

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    Thanks everyone those are a lot of great ideas, it would probably help if I made the same beer over and over to see what's going on to cause this but I think that has the potential to get boring after about 5 pale ales of the same gravity, etc. Maybe some SMASH pale ales with different hops would help with that.

    I have been reluctant to buy a pH meter after reading about their inaccuracies on here and online, and the relative easy of getting close enough with Morebeer software since my water is well documented.

    I may try to crush the night before, however, so as to keep brew day moving along. A classic trade off of time/$ I guess vs. buying a few more lbs of grain (MoreBeer won't crush twice -- I called and asked).

    I feel pretty good about my process after so many batches and usually hit temps fairly regularly. I've also read that modern 2 row varieties are a lot more forgiving than in the past. Does anyone have experience otherwise?
     
  9. Minbari

    Minbari Well-Known Member

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    Unless you buy a lab grade ph meter its not going to be perfect. But store it properly with storage solution in the cap. They work well enough
     
  10. TetersMillBrewing

    TetersMillBrewing Active Member

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    #10 TetersMillBrewing, Sep 28, 2021
    Last edited: Sep 28, 2021
    Out of everything above your cheapest bet is the advise Minbari gave. Go to the drug store and get a bottle of iodine to see if all of the starches have been converted. I just get a teaspoon with wort on it and put one drop of iodine in. If there is starch left, it will be black and will not dissipate at all. If the starch has been converted to sugar it will dissipate quickly without turning black. Cut a potato in half and put one drop of iodine on it, the result is what you don't want when testing your wort. I purchased a mill and was crushing my grain before I started making beer and will add a +1 on needing a good crush. With only about 22 batches under my belt I have just now started using a pH meter, more for documenting than anything else.
     
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  11. Minbari

    Minbari Well-Known Member

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    +1 on that.

    I use mine just to verify that my ez water sheet came out right. Usualy does
     
  12. Michael_biab

    Michael_biab Member

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    After reading more replies, and reading BFs info on conversion efficiency, I wonder if I'm measuring it correctly? Could you weigh in please?

    For "mash complete", I usually measure SG with cooled wort in a hydrometer and measured the volume of wort AFTER the bag is pulled out. (BF indicates this is what determines Conversion efficiency)

    If I measure wort volume BEFORE pulling the bag out, I can see how that would throw things off a lot.

    In BF documentation on "mash complete" / conversion efficiency, it only says "prior to sparging" and "wort volume from draining the mash to the kettle before any sparging" but since this is BIAB I don't sparge and it's not clear to me how to measure the wort volume (BEFORE or AFTER pulling the bag).

    Thoughts?
     
  13. Minbari

    Minbari Well-Known Member

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    I measure in the boil pot with top up water.
    After boil and after in the fermentor with top up water(if needed)
     
  14. TetersMillBrewing

    TetersMillBrewing Active Member

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    I was having problems with my numbers as well and things have leveled out since I took the time to actually read some of the DOCS. I start with the recommended strike water in my mash tun (normally), and take a sample of the wort before I start sparging. Doing it this way my conversion is normally at 100% or in some cases over 100% which I am assuming has something to do with the amount of strike water not being correct. Not BIAB so I am not sure if there is a difference. I am sure someone knows the technical info behind this, but I am assuming grain absorption plays into the total volume of water which in turn changes the SG.
     
  15. Mark Farrall

    Mark Farrall Well-Known Member

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    I take refractometer readings before pulling the bag out, once the bag is out and squeezed and then after any water is added. I only record the final one for mash complete, but I'll note down if extra water is needed as it may mean I need to update my equipment profile.
     
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  16. Herm brews

    Herm brews Well-Known Member

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    I am a BIAB brewer. For mash complete, I drain and squeeze the bag, then measure wort volume. After that measurement, I collect enough wort to fill my hydrometer test tube, then measure that with a hydrometer. I also cross reference with my refractometer. After measuring with hydrometer, I will pour that wort back into the kettle as it heats toward the boil.
     
  17. Dirty Dingo Brewing CO.

    Dirty Dingo Brewing CO. Active Member

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    First all, don't worry about efficiency. Genus Brewing has a saying, consistency over efficiency. Efficiency only REALLY matters at the commercial level.

    That being said, I work for a LHBS and a commercial brewery. The biggest change we've done to raise our efficiency has been the milling.

    The Univeristy of Minnesota did a study on how to maximize efficiency, and their system is utilizing a percentage ratio of corse to fine, with 4 different selections.

    I suggest looking for that study. With BIAB you don't need to worry about a stuck sparge, so you can go a fine as you wish.

    We took our efficiency from 80 to 87 at the commercial level doing this and 70 to 80 at the LHBS.

    Secondly, mash PH is EXTREMELY important.

    Everything that everyone is saying is 100%. Iodine testing is also great

    Bottom line, focus on your recipes taste over efficiency. I know it's hard, I was the same, but now I hit my targets every single time
     
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  18. HighVoltageMan!

    HighVoltageMan! Well-Known Member

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    I hate to quote myself, but CausticWolf has said one way (simpler and more concise than me) and I put numbers to it. Get to know your system, grain, water etc. Evidence of brewing consistently will bear out in the numbers. An anal retentive personality helps with these sort of things, although it can be annoying to others.
     
  19. Nosybear

    Nosybear Well-Known Member

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    Efficiency at our scale means a few handfuls of grain, a trivial investment. We need to know it for recipe formulation, otherwise it's not much use except to impress other brewers at the homebrew club meeting. Improving efficiency is not making better beer! I note mine in my brew day notes then largely forget about it.
     
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  20. BarbarianBrewer

    BarbarianBrewer Well-Known Member

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    I knew there was something missing from monthly BF Zoom meetings! :p
     
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