Too efficient. To water down or not?

This my 3rd or 4th AG batch but first time I've really tried to dial in my system.

I brewed 10.25 gallons of Orfys Mild and based on the recipe in Beersmith OG calculated with 70-75% efficiency was 1.037 to 1.040. Everything went well, hit volumes perfectly and was spot on 158F target mash temp.

I have a refractometer so I checked first and second runnings gravity, preboil and post boil. Turns out everything went too well and I came out at 1.050 OG post boil of 10.25 gallons! I confirmed this later with a hydrometer sample as well. Efficiency came out at 93%! I realize if volumes are off by a quart or two it will change. But even if I'm only at 9.75 into fermenter, I'm still at 90% efficiency. Is this reasonable?

Second question. I'm right on volumes I want but I'm off by about 10 gravity points. I'm worried the FG is going to be way high with the 3lb crystal and high mash temp. I could add a gallon to each fermenter and get it back down to a reasonable OG. Should I top off now, let it be, or top off after checking FG?

Thanks guys and girls

If you decide to top it off make sure you boil the water you're going to add and let it cool before you make the addition.

I personally would add the water. I like to make the beer I set out to make. Many will tell you not to do so and that's fine as well. However, you'll never know what that recipe tastes like until you actually make the beer as you set out to do.

Good luck, I hope it turns out well.

cp

Sounds like you went from mild to brown. Did you grind your own grain, or weight the grain you bought? Seems like a really high efficiency to me.

Good point about the crush since that almost certainly played a role in the high efficiency. I crushed it at Northern Brewer with their preset spacing. I didn't like the crush on the first 10lbs of Maris Oter so I ran it through the mill a second time.

I keep some bottles of spring water around for such times. I don't bother to boil it or anything, just dump in. I didn't boil the spring water I used when doing extract so why start now....

I adjust with water pre-boil to get the right gravity (if efficiency is high) and then check the gravity mid boil to decide if the heat needs to be turned up/down/left alone. Pre-boil gravity is important for hop utilization especially if your efficiency is off 15%.

Im thinking the way to avoid this in the future is to not be off 20% on efficiency. Seems no matter when i add water its going to change the recipe slightly from what i expected.

Fermentations already going and seems almost done. If gravity comes out too high im thinking anout adding some water to top off. I assume i should boil this top of water first to scrub out the oxygen, correct? Or does not matter.

I agree with dstar - adjust when you take the pre gravity reading. That is one of the main advantages in using a refractometer to check the pre & mid boil gravities.

Great ideas, especially about checking gravitymid boil

You could add the water post boil and still adjust your hop calculation as well. My brew chart accounts for this actually which is why I add the water post boil. It allows you to be a little more accurate as you then know your final post boil volume and gravity so that you can adjust accordingly.

The hop utilization calculation I use is based off of average boil gravity. Your final IBU's in the beer are based upon the utilization of those hop additions during the boil and then divided by your final volume.