Efficiency Confusion

I just want to say thanks ahead of time.

So I just did my second all-grain brew last Saturday and so far turned out pretty successful, I think. However, efficiency has started to confuse me a little. I was using Brewer’s Friend website to help me in the process.

The recipe was for a 3 gallon batch. With my own recipe based off a 70% efficiency.
I heated up 6 gal of water, more than needed. Used 9 qts of it for strike water and then another 12.4 qts for sparge. Got rid of the rest. 21.4 qts are now in the mash tun. Now I know I lose about 2.25 qts of water in my 10 gal cooler mash tun. I also used 6 lbs of malt. My one mistake was that I didn’t check the volume that I drained out mash tun, however, the hydrometer reading was 1.041, Pre-Boil efficiency of 80%, assuming that I drained 17.2 qts. A quart more than the Brewer’s Friend calculator assumed.

Here is the part I’m really confused about. Once the brew day was complete. Instead of ending up with 3 gallons, I ended up with 4 gallons in the fermenter with my actual gravity being 1.048. The expected final gravity was supposed to be 1.052. This apparently shows that I got an 86% efficiency.

Can someone please help me understand what’s going on here and what I need to do the next time I brew this same recipe. All a little confusing.

Thanks a lot.

if you put 21 quarts in with 6 lb of grain and got 17.5 out you do not have 2.25 quarts deadspace.

A pound of grain will absorb about .12 gallons or ~1 pint of liquid and not let go of it. so 6*.12 = .72 gallons or close to 3 quarts that’s down to 18.4 quarts. That less your deadspace should equal your pre boil.

Efficiency calcs are all suspect without really solid volume measurements.

I can’t help. I’m one of those people who only care about brew house efficiency for recipe building,  and then only a little. I use brewer’s friend too. What I do is pretty simple. I build a recipe on 70% efficiency predicted. Then I measure my fermenter OG before pitching. Then I adjust the efficiency in brewer’s friend on that recipe so the predicted OG matches what I got. Depending on the beer I get between 65% on high gravity beers to 75% on beers around 5% abv. Its not precise for sure, but I only care about efficiency for recipe building. I know this doesn’t answer your question. But maybe it will help to know that efficiency is not vital unless you want it to be.

are you using a false bottom or a braid in your mash tun?

so if you used 9 qts for strike water thats 2.25 gallons. using a .125 gallons/lb absorption rate you would have 1.5 gallons left from your initial mash. if you sparged with 12.4 qts thats another 3.1 gallons for a total of 4.6 gallons before any loss from liquid left in your MLT.

do you know your boil off rate & how long was your boil?

I appreciate the feedback.  Like I said, that was the one mistake I feel I made when brewing this batch.  I’ll probably end up brewing the same exact batch and recipe and look more closely at volumes.  I took 4 hydrometer readings throughout, which I’m starting to think is overkill.  What readings do you usually see yourself taking throughout the process?

When I first started tinkering with the notion of going all-grain, efficiency came up all the time.  However, I’m starting to lean towards your way of thinking that efficiency is good for recipe building, but how do you know what efficiency to use to begin with?  I would think it’s more important that the end product stays consistent and within it’s style guidelines, then making sure your getting the most out of your system.

I boiled for exactly 60 minutes.  I don’t know what my boil off rate is.  This was only my second batch with a full boil.

I generally take a pre boil reading about 2 minutes after the boil breaks. Fill a little half cup mason jar, seal it up and pop it in the freezer to chill. Then I take a post boil reading with the same strategy.

Once in a while when I’m feeling super sciency I will take a reading from the mash to attempt to determine conversion efficiency but then you need to be really really precise with your volume measurements and I’m not always.

for what it’s worth, I use a refractometer for my readings so it only take a tiny bit (I take about 4 floz anyway, just for tasting purposes) when I used a hydrometer I would sometimes take a pre boil but generally only took a post boil. the benefit of the pre-boil is, if you know your volumes and you have some DME or LME or sugar around you can bump your gravity if you miss. I suppose you could water your wort if overshoot too but that’s better done post boil.

Thanks a lot, I’ll keep this in mind for my next batch.  Probably doing it again this weekend.

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When I first started tinkering with the notion of going all-grain, efficiency came up all the time.  However, I’m starting to lean towards your way of thinking that efficiency is good for recipe building, but how do you know what efficiency to use to begin with?  I would think it’s more important that the end product stays consistent and within it’s style guidelines, then making sure your getting the most out of your system.

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I use experience as my ballpark guess when starting a new recipe. If its a big beer I put 65% in there. Otherwise I use 70% and adjust from there. When I rebrew im usually within a couple points of my targets.

Your last sentence I agree with partially. I dont care about most out of my system. If I use a bit more grain so be it. I care about guidelines only if I send a beer to a bjcp comp, which I’ve done once so far. I care always about fun, enjoyment, learning, a little repeatability, etc.

When I first started tinkering with the notion of going all-grain, efficiency came up all the time.  However, I’m starting to lean towards your way of thinking that efficiency is good for recipe building, but how do you know what efficiency to use to begin with?  I would think it’s more important that the end product stays consistent and within it’s style guidelines, then making sure your getting the most out of your system.

[/quote]

I use experience as my ballpark guess when starting a new recipe. If its a big beer I put 65% in there. Otherwise I use 70% and adjust from there. When I rebrew im usually within a couple points of my targets.

Your last sentence I agree with partially. I dont care about most out of my system. If I use a bit more grain so be it. I care about guidelines only if I send a beer to a bjcp comp, which I’ve done once so far. I care always about fun, enjoyment, learning, a little repeatability, etc.

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Thanks for the clarification.

You bet

Efficiency calcs are all suspect without really solid volume measurements.

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What readings do you usually see yourself taking throughout the process?

For consistency reasons I always take a pre boil hydrometer reading poured into a small ss bowel in ice water that I can chill in a few min to 60F. I then can adjust my boil to insure I hit my desired FG. I take hydrometer readings at 20 min intervals and adjust as needed. Most always hit my FG.

What kind of things do you do when you notice that your either too low or too high?

Three choices

1 - boil less if over
2 - boil more if under
3 - nothing

I like number three the best

+1 to Steve’s advice. Also :

1/ Verify that your volumes were measured correctly - mash, sparge, grain absorption, dead space, preboil, post boil.

2/ Look at your crush. This is a prime cause of low or fluctuating efficiency. If you don’t have a mill, your LHBS will double crush your grain. You’ll get much better, more consistent efficiency. Then buy a mill.

3/ If you’ve worked on these two areas and your efficiency calculates pretty consistently in the same area, then your efficiency is what it is. Then just change your efficiency in your software to the consistent value. This will help you hit your target OG in a recipe pretty accurately and consistently.

Thanks to everyone that has replied to this thread.  It’s been pretty helpful.  Can’t wait to do my third batch this weekend.  Not changing the recipe at all, just making sure I get all my volume’s and measurements correct.  I’ll probably be working on that for the next couple of brew sessions.

Thanks

One thing to keep in mind is sugars are never boiled away, they are conserved. So what you wanted in the kettle post boil was 1.052 with 3 gallons or 52 x 3 = 156 points

You got 4 x 48 = 192 points

6lbs of grain has the potential of 6 x 36 = 216

So 192/216 = 89%

My gut tells me there is quite a bit of imprecision in your measurements based on that high efficiency so early in your AG brewing career. If you actually had 4 gallons even after all was said and done then based on your gravity measurement you had 4.68 gallons in the kettle (192/41)

If you want to hit a gravity precisely you can calculate exactly how long to boil once you establish your boil off rate. If you boil off a little too much, you can calculate how much water to add to end with a particular gravity. Of course all the measurements need to be precise. HTH

Hitting a specific gravity every time doesn’t concern me as much as knowing what specific gravity I need to base my recipes off of to meet approximate style guidelines.

This may sound funny, but tasting like the style is more important than the numbers. (If your competing) Otherwise, tasting the way YOU like is most important

+1

I would dedicate a ruler or make lines on a nylon spoon or use some method to gauge your water precisely.  Use a bottle with a known specific volume to incrementally fill up your mash tun and boil kettle (unless they are virtually the same type of vessel - then just do it for one of them), going say, a gallon at a time and marking it on your ruler or spoon or stick or whatever, so that you can have a reasonably good gauge of volumes.  This will allow you to know your volumes as you go and allow for differing boil off rates given differing humidity levels, etc…  I have found this to be invaluable even now after many, many batches.  Once you get things dialed in, you will hit specific marks based on grain amounts almost without thinking.

Cheers! and welcome to the forum. Read Denny’s bottom line for what most people think about this forum - a great place.