Brewhouse efficiency?

Mashing
1

So I am finally getting my AG processes dialed in. After a move it took a while to get things the way I wanted them and to re-invent my processes. Next major thing is water chemistry, but that is for another day.

So the last two batches were my first all grain lagers. I did an Octoberfest on Friday and a Czech Pilsner last night. Both of them ended up 4-6 points higher than my estimated Starting Gravity after plugging my recipes into BeerSmith. It is a little weird because my pre-boil gravity was maybe a point high.

I am starting and ending up with proper volumes, really dead on. Boil time is 60-75 minutes, but I plug that in.

I am not sure how to adjust going forward. I really would not change my brewhouse efficiency unless I was missing my pre-boil gravity, right?

2

[quote=“560sdl”]So I am finally getting my AG processes dialed in. After a move it took a while to get things the way I wanted them and to re-invent my processes. Next major thing is water chemistry, but that is for another day.

So the last two batches were my first all grain lagers. I did an Octoberfest on Friday and a Czech Pilsner last night. Both of them ended up 4-6 points higher than my estimated Starting Gravity after plugging my recipes into BeerSmith. It is a little weird because my pre-boil gravity was maybe a point high.

I am starting and ending up with proper volumes, really dead on. Boil time is 60-75 minutes, but I plug that in.

I am not sure how to adjust going forward. I really would not change my brewhouse efficiency unless I was missing my pre-boil gravity, right?[/quote]

if your post boil gravity was higher than expected, while still accounting for higher efficiency, i think the measurement error is because of one of two things: post-boil volume or pre-boil SG.

I don’t use beersmith…does it give you a preboil efficiency? I measure mine, but only because I’m interested in knowing that i’m getting ball-park levels of sugar out of the process but it is not something I really care about. My main concern is for post-boil SG so I have a starting point for may yeast.

For most of us, it’s really hard to get an exact post-boil volume measurement too. unless you measure the amout of wort going into your fermenter, quart by quart with zero crude transfer, you’re going to have some error due to the volume of crude that also transfers to to fermenter. Just having a line on the fermentor at 5 gallons, doesn’t tell you the wort amount but wort plus crude, and crude volume changes with every recipe.

I think most software is set for 75% efficiency. I routinely get 85-90% efficiency, so that means I have two options to get my OGs/FGs down to closer to the expect value. Either add water or cut back on grain. Adding water (like we did with extract) is easier.

Bottom line: great efficiency is a blessing, not a curse.

:cheers:

3

No, don’t get me wrong, I am thrilled with the efficiency. Beersmith does not give a “pre-boil” efficiency % but rather an estimated pre-boil gravity. I usually pull out 4-6 oz just as the wort starts to boil, let it cool and check the gravity. It is usually very close to what is expected, but never lower which is what I really look for. I will be more careful going forward to make sure that is not 3-4 points high at that point.

I ended up adding a little water to my Czech Pils because I did not want it to be two strong. I was up at 1.060 and that is probably 10-11 points higher than I wanted. I only added a bit of water though.

Bottom line, I think I will up my efficiency by 5% in the program and see what happens and adjust from there.

4

Based on personal experience, you need to make sure your wort is thoroughly stirred before checking pre-boil gravity. The initial runnings will be higher gravity that the later runnings and you can get stratification of the wort in your kettle. If you don’t stir the wort on top will be lower gravity than the wort on the bottom. Stir first before drawing off your sample to get a good pre-boil reading.

After the boil, the gravity should be fairly uniform throughout the kettle due to the boiling action so you don’t need to worry as much about your readings then. If your initial pre-boil reading is off on the low side due to wort stratification, this could explain why your SG is higher than you expect given that you hit your volumes. Maybe your pre-boil gravity is actually a bit higher than you think.

The Homebrew Nerd

http://thehomebrewnerd.com
5

I for one am not all that concerned with how the numbers work so long as they consistently work. I’ve found out how to use Beersmith so that I can formulate a recipe at a 5.25 gallons with 73% Brewhouse efficiency and come pretty damn close every time. That’s all that matters to me, I’m lazy and don’t care though. Consistency is what matters.

6

Absolutely. Efficiencies are some of the most useless numbers in homebrewing. Don’t get me wrong, extracting as much of what the grain has to offer is important, but how we measure it is quite a point of contention. You want to hit the gravities that the recipe calls for. That means consistency, not necessarily efficiency. If you knock your brewhouse efficiency in BeerSmith down a bit and are able to hit your gravities consistently, then that is what you need to do - raw numbers be damned.

I discuss this in quite a bit of detail in a write up I did here:

http://handsonbrewing.com/2012/02/the-efficiency-myth/

Good point on stirring your pre-boil run off. This is very important, especially with a very slow sparge like most of us do. As for post boil gravity, I consider this optional. If you know your pre-boil gravity and volume to a high degree of accuracy (have an accurate sight glass and an accurate hydrometer and adjust for temperature), then your post boil volume and gravity are a foregone conclusion with the calculator built into your brewhouse software of choice.