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Missed OG

I know it’s happened to every new AG brewer and you may be tired of answering the question, but after spending most of the day researching, I turn to you more experienced brewers.

Brew day went well, I thought. Results don’t show it.

In brewing a 5 gallon batch of ESB, I missed by 10 points (target 1.60, actual 1.50).

Here is the setup: 5 gallon cooler MLT with false bottom, 5 gallon cooler HLT. Heated 3.75 gallons of strike water to 166 with a target of 150. Grains were milled by HBS and set a room temp (68-70). Actual temp in MLT 151 for 60 min. Recirculated for 10 min and fly sparged with 175 water in the HLT (lost 4 degrees in HLT, so 171 was sparge temp) at a rate of 1 gallon every 12 minutes. Collected 6.25 gallons

The recipe was 11lb 2 row and 1lb Crystal 60. What can I do to increase efficiency? When I took a gravity reading after my mash, it read 1.20-1.22.

When you took the gravity reading before the boil, it must not have been mixed well. No way you are going from 1.020 to 1.05 by boiling off 20% of your liquid.

That is most of what I got. I just did my first all grain batch yesterday and totally underestimated the boil off amount, but when I topped off with water to get to 5.25 gallons, I hit the gravity spot on.

Could be the crush. I read on here a lot that you should have the LHBS crush twice

Thanks 560. I didn’t have to add water to the fermenter, so I know that was not a factor. All and all, I was prepared and happy with the session.

Previous AG batches were learning experiences and I put that info into practice in this session. Results should have been better than previous attempts.

I was just saying that the gravity reading you reported, pre boil could not be right and. Did you mix the first runnings with the second or sparge runnings before that reading? The math just does not work to get from 1.02 to 1.05 boiling off 1.25 gallons.

I didn’t stir before either gravity readings, that maybe where I went wrong. Thanks!

Not mixing the first runnings with the sparge water would clearly leave the less sweet wort on the top and throw that reading way off.

You should not have had to mix before the second, unless you topped off with water. Couldn’t hurt, but should not be necessary. I usually check mine after my vigorous aeration and just before pitching yeast.

We just started brewing all grain a few months ago and we noticed that we were not hitting our marks either so after a handful of batches I we calculated our efficiency and found out we were operating somewhere around 65%. Now I downloaded a copy of Beersmith, set the efficiency at 65% and plug in every recipe we plan on making and then simply add base malt to get up to the OG of the kit we will be using.

12lb of grain would give you 432 pts at 100% efficiency. You got 50 x 5.25 = 262 pts, or about 61% efficiency. Thats about 10-15% lower than what you could get with a good crush, complete conversion and good recovery from running off.

Fly sparging means you could have lost some sugar due to channelling of your sparge water through the grain bed, be careful about this. You want to go slow, and be sure the grain bed is a decent thickness (mashtun geomtery is more important with fly sparging).

I’m a little confused about sparging. When you fly sparge and keep a couple of inches above the top of the grain, why does it matter how the water comes out of you HLT? How does channeling occur?

I have read the “Bible” on homebrewing and researched many resources online, but don’t understand how I can improve efficiency through sparging techniques. This batch of brew took over an hour to sparge and I would think that alone would yield great results.

Water takes the path of least resistance and if there is a “crack” in the grain bed a lot of water will funnel down through it rather than percolated through the whole bed like its supposed to. This happens more often when the grain bed is fairly shallow. I’m no expert on fly sparging though.

Did you collect wort until you reached a low gravity coming out?

Personally I like batch sparging, I can pretty much calculate what I’ll get that way. Its a simple extraction calculation, you know how much total volume and how much the grain holds, so you know the percentage of sugar left behind.

And honestly, its more important to be consistent than it is to get super efficiency. I know I get 75%+/- a few percent, I can count on that. I don’t care if its not consistently 80%. I can formulate a recipe aiming at a mid-range for the style and hit my target every time.

I collected until I had the volume needed for boiling, including evaporation.

Using a strainer to diffuse the sparge water coming into the MLT.

I would switch to batch sparging for at least the next mash. That way you can take some measurements to determine where you’re losing efficiency, and go from there. … Efficiency

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