Dialling In Efficiency

Hi team,

I'm hoping you can help me with some issues I am having nailing down my efficiency in relation to boil off, losses & BH efficiency. There's a few questions that I have & I will try to be as succinct as possible, but if you need any further information please ask.

My issue is that my expected OG is higher than what I am getting. When I first started using the software I had not entered my losses, so effectively BH & mash efficiency were the same. I was often mashing in the mid 70% efficiency, but then BS would predict a 10-15 point gain during a 60 minute boil off and I was only seeing a 5-6 point gain.

This caused me to properly go through all my processes & work out what was going on. I am now confident, that my equipment profile is dialed in, but I'm still getting incorrect data. I have done a boil off experiment to confirm that my boil off rate is 3L per hour. I have also previously measured my kettle trub to 1L. This has been entered in as well.

Based on this data on a recent recipe, Beersmith (with 70% BH efficiency & 74.8% mash efficiency) expects the following;

Pre boil gravity - 1.048
Post boil gravity - 1.063

My actuals were:

Pre boil gravity - 1.048
Post boil gravity - 1.054

So I hit the mash efficiency as usual, but way off on the OG. If I wanted to match the OG in BS I would need to drop the BH efficiency down to 64% with a predicted mash efficiency of 68% & pre-boil gravity of 1.041, which is way under what I got.

What am I missing here? With the information I have, ie boil off rate, pre-boil gravity & post boil gravity & pre & post boil volume, what is the easiest way for me to dial in this equipment profile? I want to clarify, I'm not that concerned with chasing numbers, I just want to be able to rely on this software to properly predict the outcomes.

Appreciate your help!

It sounds like you are doing the right things to get your process defined in the equipment profile.  Your discrepancy in the post boil gravity reading initially looks to be an issue with your boil off rate, but that is judging from just the gravity readings alone and efficiency is really a volume x gravity metric.  The first thing to check is how accurate are your volume measurements.  I have three brewing vessels with pre-etched volume markings and only one of them is even near close when I add measured amounts of water and make my own measuring stick. 

I would also recommend, if you are not doing so already, that you take gravity measurements at or near the calibration temperature of your hydrometer.  There is just too much noise in measuring a hot sample and trying to correct that to calibration temperature.  If you are using a refractometer, make sure you are reading the Brix scale and then converting to gravity.  Many reasonably priced refractometers are not very well calibrated when it comes to the specific gravity scale.

If you give the same analysis you did with the gravity readings for your volumes, starting with your total water volume, it would help in giving us the information needed to help you further.

If you don't already start listening to the podcast and reading the website articles at www.Brulosophy.com. Their most recent podcast as of this writing is about efficiency and how to get the most of it. Both of the hosts use Beersmith so the reference it throughout the episode. And, the address your issue directly with steps to correct it. There is also a companion piece article on the website called 6 tips for dealing with efficiency problems... http://brulosophy.com/2015/09/10/6-tips-for-dealing-with-efficiency-problems/

Thanks guys,

Yeah, that's about the only thing I haven't done - is actually measure the liquid in my kettle elsewhere. I use a SS Brewtech 20L kettle & have trusted that the markings are correct, but maybe they're not. If I reverse the the pre-boil vol x pre boil gravity / post boil vol formula with the known numbers, then my actual boil off rate would be about 1.9L per hour. I will check this tonight.

Yep, always cool my wort before checking gravity.

& yes, I am an avid listener of the Brulosophy podcast & have listened to this week's episode. It's what got me thinking again about this issue & wanting to resolve it!

Thanks!

Oh, & to your other question. My volumes are like this...

Mash with 12L of strike water

Dunk sparge into 7L of water

Top kettle up to 17L of pre-boil volume (1.048)

60 minute boil down to 14L post boil volume (1.054)

Rack 13L into my FV

I don't know if it's something to do with the volumes, as I'm not using the exact amount of water that BS tells me to in terms of the split between mash & sparge volumes, but the total volume is the same, about 20L.

So you mash in with 12 L +/- and sparge with 7 L +/- with the total being around 20 liters.  Are these volumes at room temperature or at strike/sparge temperatures?

How much are you adding to bring your pre-boil volume to 17 liters?

If I look at the sugar balance, you start the boil with 17 liters at 1.048 gravity which gives you a starting amount of 17 liters * 48 gravity points = 816 sugar points
At the end of the boil you have 14 liters at 1.054 gravity which gives you an ending amount of 14 liters * 54 gravity points = 756 sugar points.

These two numbers should be equal or roughly equal unless you are taking out some of the wort post boil or during the boil which would account for the 60 sugar points difference.

This also suggests that if your volumes are correct, that one or both of your gravity readings may be in error.

Kevin58 said:

If you don't already start listening to the podcast and reading the website articles at www.Brulosophy.com. Their most recent podcast as of this writing is about efficiency and how to get the most of it. Both of the hosts use Beersmith so the reference it throughout the episode. And, the address your issue directly with steps to correct it. There is also a companion piece article on the website called 6 tips for dealing with efficiency problems... http://brulosophy.com/2015/09/10/6-tips-for-dealing-with-efficiency-problems/

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This is good advice here!  Great podcast and website!

I, too, have been having the same issue as the OP lately, and I have to wonder; I've set up a bunch of Equipment Profiles for the various styles I brew, but only have a few basic mash profiles to cover all the different types of beer I brew. Granted I'm not all over the map concerning beer styles, I stick mostly to ales from a 1.050 Kolsch to 1.068 IPAs, wheat beers, stouts and porters, and the occasional IIPA clocking in at around 1.080 or so, depending on my mood, planetary alignment, etc.

Should I also be creating Mash Profiles for each of these styles to pick up subtleties like higher water to grain ratios for larger grain bills or where flakes grains are used, lower mash temps for a dryer finish, etc.?

I have been noticing my BH efficiency takes a hit when I increase the grain bill. An example is I have my Kolsch Equipment Profile set to 82% BHE and I nail my targets. That same profile won't work for my IPAs as there is a ton of hops soaking up water (so my IPA profile has those volume differences accounted for) and the grain bill is more than 50% larger - I had not accounted for that drop in efficiency because I did not know about it. Until now. My IPA profile now boasts a 76% BHE so we'll see if that does the trick next time I brew an IPA in a couple of weeks.

What are you folks doing with your mash profiles? Are you creating one for each different type of brew?

I have one basic equipment profile which defines my process losses and capabilities.  It fits for the vast number of styles which I brew, after all dead space is dead space and boil off rate is the same with the same equipment using the same heat source.  Like you, I do a variety of styles having started my "brew season" this fall with some IPAs and English styles before transitioning to lagers right now.  Come late winter, I will transition back to some American styles from wheat to PAs to IPAs before ending up with a couple of Belgians in mid-spring.

I do have a variety of mash profiles which cover an array of mash styles and temperatures.  For me there are a set of single infusion profiles all BIAB, profiles with a batch sparge for higher gravity brews, and then some specific profiles for decoctions and glucanase rests.  The first two sets cover 90% of my brewing with the only variable being the mash temperature.  Everything else about a given set of the profiles remains constant.

My focus is less on the BHE and more on the mash efficiency which for me is reasonably consistent until I get to higher gravity brews.  Most people do see a drop in mash efficiency as the grain bill increases.  It is at this point I use the mash profiles with the sparge step in order to keep my mash efficiency consistent.  Since the BHE contains process losses in the calculation, it is more subject to variation depending upon the type of recipe I am brewing.  To equalize this, I set a standard loss to trub and chiller at the end of the process to be 1 liter so that my typical 10 liter batches actually come out to 11 liters at the end of the boil.  In doing this, I sometimes leave wort behind in the kettle (which I sometimes use as a starter for the next brew) along with the coagulated proteins and hop debris, but it does help to keep my BHE consistent.

philm63 said:

I have been noticing my BH efficiency takes a hit when I increase the grain bill. ...My IPA profile now boasts a 76% BHE so we'll see if that does the trick next time I brew an IPA in a couple of weeks.

What are you folks doing with your mash profiles? Are you creating one for each different type of brew?

Click to expand...

When the batch size is consistent, higher gravity beers get less efficient. Simply, there is ratio of water to grain needed to extract all the sugars in a given weight of grain. Most of the time, the kettle is full before a high gravity beer reaches that ratio. You can slow the sparge (or increase the second soaking time and stir for batch sparge/biab) to get a bit more out of the grain, but in my experience it's often not worth the results.

What you can do is sparge out the grain into another pot, boil it to about 1.035 at 10 ibu's, and you have some handy starter wort for the next batch.