Possible Efficiency Problem?

I just brewed a stout today and the target OG was 1.071 for a 3.5 gallon batch at 70% efficiency set in beersmith.

I was planning on collecting 4.5gallons of wort in order to get my 3.5gal target after a 60min boil. What actually happened was that I collected 6.4 gallons and ended up boiling it down to 3.8 gallons after 105minutes with an OG of 1.073. I still had some sugars left because my refractometer read 1.016(4brix) when I stopped sparging. If i had stopped at 4.5gallons there would be way too much sugar left behind in the mashtun. Is this because my efficiency is actually higher than I think? Beersmith is set to 70% If I were to calculate this recipe with an 80% efficency and change the amount of grain accordingly will this solve the problem? i'm kinda confused. I absolutely dont want to waste precious sugars left behind in my mash tun just to get such a small boil volume. any help would be great.

Thanks!

When you wort drops below 1.019 you risk tannins.

cfonnes said:

When you wort drops below 1.019 you risk tannins.

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I think you can safely sparge to 1.010 in most cases.

But next time, either stop sparging when you reach your boil volume or by the time the runnings are at 1.010! 1.004 is way too low. You definitely oversparged.

cfonnes said:

When you wort drops below 1.019 you risk tannins.

Click to expand...

My mistake. I meant 4 brix on the refractometer. The gravity was 1.016 when i stopped.

Yooper said:

I think you can safely sparge to 1.010 in most cases.

But next time, either stop sparging when you reach your boil volume or by the time the runnings are at 1.010! 1.004 is way too low. You definitely oversparged.

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I meant 1.016 or 4brix. The thread has been updated

klamz said:

My mistake. I meant 4 brix on the refractometer. The gravity was 1.016 when i stopped.

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oh, then you're ok. Most people take a small hit on efficiency (leaving those precious sugars behind as you put it) to avoid a 3 hour boil. I just sparge to my boil volume and call it done.

Yooper said:

oh, then you're ok. Most people take a small hit on efficiency (leaving those precious sugars behind as you put it) to avoid a 3 hour boil. I just sparge to my boil volume and call it done.

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I did the math and according to John Palmers formula I have about 90% efficiency. I guess my ultimate question is how do i adjust my recipe for 90% efficiency. This stout is from Jamil's book which is all based on 70% efficiency. So my recipes are scaled a tad too high. do i just decrease the base malt or all the malts across the board? and is there an options or calculator that does that in beersmith?