First AG batch - needed to boil for 120 to reach correct volume/OG

I used beersmith to calculate water amount for my first AG brew. What's weird is that after sparging, I came out with more water than beersmith anticipated, and at a lower OG.

That being said, I was able boil down the wort and still reach my OG & volume. Though, I had to boil for almost twice as long (120min vs 75min)

Here' what beersmith had me do for a 5gal batch.
4 gallons for 12.5 lbs of grain mashed @ 149F
2.6 gallon @ 185F for batch sparge 1
2.6 gallon @ 185F for batch sparge 2

With 12.5 pounds of grain and 2 lb of sugar, it came out to 1.048 @ ~ 8 gal. Beersmith wanted to see something like 7.3g @ 1.053. Post-boil needed to be 1.078 @ 5 gal.

Just curious what may have been wrong here. Given that I met my OG post-boil, I think I extracted the right amount of sugar from the grain.

Is beersmith just wrong on the evaporation rate for the length of boil time? If so, how would I have been able to exract this amount of sugar with less sparge water, to get the batch to 1.078 @ 5gal with a 75 minute boil?

Or is it common to have to do longer boils with big beers to meet the intended OG?

I had to boil my first AG for 3 hours to reach volume....good times. I think you can use the calculators and tools to give you a good base-line, but in the end it comes down to trial & error experience based on your equipment.

Turtle: What have you improved in your process since then to reduce boil time?

My first attempt I had 3 gallons in my biab mash, and sparged with total 5 gallons, exactly as the recipe and calculators told me. I had an 8 gallon kettle, so surely it would hold 8 gallons right? Wrong, after adding my mash 'runnings' to the kettle, I had to scoop a bunch of it back out just before it boiled out all over my patio.

Now I still mash in about 3 gallons based on the recipe, but I only sparge with 3.5 gallons to total 6.5 gallons, which works out to be the perfect amount for my kettle to boil 60 minutes and end up with 5.25 gallons.; and there's no risk of boil-over. So if I were to mash in 2 gallons for example, I would sparge with 4.5 gallons in kettle for a 60 minute boil. If I mashed in 4 gallons, I'd sparge with 2.5 gallons, etc.

Hopefully I'm using all the terms correctly, I just finished my second AG yesterday...but everything went perfectly.

I also do BIAB, and it seems like most calculators overestimate the amount of water that you need.

Personally, very similar to turtle, I mash in 4 or 5 gallons and dunk sparge in 3 or 2 gallons (depending on grain bill), which gives me right around 6.5 gallons of wort after I squeeze the bag, and I end up with 5.25 gallons after a 60 minute boil.

Everyone's equipment, methods, and environment are different, which greatly affect how much water you use based on evaporation, absorption, etc. So, the calculators only give you a rough estimate. After a few brews, you'll quickly learn what your equipment does and have it nailed down so that you'll be within 1/4 gallon of your target.

OK...the best thing to do is to not over complicate things. ! good rough estimate is 1 gallon per hour for boil off...now this can go up or down depending on surface area of wort, vigor of the boil, etc. What you need to do is for a 60 minute boil, just shoot for a gallon over post-boil volume, and if you go under, you can always top up. Boiling for an extra hour is just plain silly. Even if you end up using to much sparge water, just stop running off the wort into the boil kettle when you reach the 1 gallon over mark for your kettle. SIMPLE!!!!!

Doesn't those longer boil times result in more bitterness from the hops being in the boil so long?!?!?!

mgortel said:

Doesn't those longer boil times result in more bitterness from the hops being in the boil so long?!?!?!

Click to expand...

only if you don't adjust your hop schedule and throw the hops in at 120 min (or whatever).

For my first AG BIAB I did BM's Cream of 3 crops, mashed with 3 gallons and then sparged with about 4. I did 2 batch sparges of about 2 gallons each. He calls for a 90 minute boil though. I boil on my stove and use an ice bath, so I try to shoot for a bit less than 5 gallons post boil and top off to 5.5 gallons with cold water to help with the cooling process.

Basically from what I have read you should adjust your sparge to reach your preboil volume. Some people will even add water preboil to avoid over sparging. I'm not sure what the exact amount is, but I probably could have just batch sparged once in 2 gallons and taken very minimal hit in efficiency.

mcaple1 said:

OK...the best thing to do is to not over complicate things. ! good rough estimate is 1 gallon per hour for boil off...now this can go up or down depending on surface area of wort, vigor of the boil, etc. What you need to do is for a 60 minute boil, just shoot for a gallon over post-boil volume, and if you go under, you can always top up. Boiling for an extra hour is just plain silly. Even if you end up using to much sparge water, just stop running off the wort into the boil kettle when you reach the 1 gallon over mark for your kettle. SIMPLE!!!!!

Click to expand...

If I stopped my sparge at 6.5 gallons instead of 8, wouldn't I have been too low on my post-boil OG? Since 8 gallons boiled down to 5 put me at the gravity that I needed to be at...

Though, maybe there is a chance that the last 1.5 gallons of sparge was pretty watery anyway and doesn't add much gravity?

EDIT: The forum server clock is wrong and it put this post at the top of the thread. This should be below Wakadaka's post.

Well you have some known constants (mostly) in the brew process, and some good 'rule of thumb' averages.

1. a pound of grain will absorb .2 gallons of water in the mash. 2-row, 6-row, wheat...its all basically the same absorption rate (rice and corn are probably different, but they'll have known absorption rates too if you google around)
2. you don't lose water to absorption during the sparge...this could be part of the problem.
3. i don't use beersmith, but did you fill in all the values for 'deadspace' in the tun and boil kettle? If you've got it set for .75gal of deadspace but you only have .25gal, that's a half gallon extra wort you'll collect from the mash and each sparge. this could be the source of your extra volume too.

4. a gallon an hour evaporation during boiling isn't a hard-fast rule but a good starting estimate for sure. Wider pots, and dry climates lose more evaporation than tall/skinny pots and humid climates.

I guess where I'm confused is this:

* If I change the sparge water quantity, then it changes the OG @ 5 gal post-boil, since I'm putting less sparge water (and hence less total sugar) into the kettle.
* If I change the boil time to boil off the extra water, it takes forever.
* If I change the amount of grain, I can hit both OG and boil time. <--- How do I do predict this and how much grain I'd need?

I guess once I know my efficiency after a few more times I can figure out anticipated PPG and vary the grain bill based on that? Given that, why doesn't beersmith edit the gain weight based on efficiency?

Beersmith allows you to change the efficiency....you will have to change the grain bill manually to get the OG you were shooting for.

This is simply a matter of increasing the amount of each grain by the ratio of the assumed efficiency and your actual efficiency:

So for example, lets suppose your grain bill is as follows:

7 lbs pale 2-row
0.5 lbs Crystal 10L
0.5 lbs Vienna
0.75 lbs Cara-Pils

And the above recipe is based on 70% efficiency, 5.5 gallons, and an OG of 1.040

If YOUR actual efficiency is only 65% (based on previous experience).....then you will need the following adjustment in grains.

70% / 65% = 1.0769

SO multiply each of your grains by 1.0769....so...

7.5 lbs pale 2-row
0.54 lbs Crystal 10L
0.54 lbs Vienna
0.81 lbs Cara-Pils

You can plug numbers into Beersmith after adjusting your efficiency and see how it works out.....

stevehollx said:

If I stopped my sparge at 6.5 gallons instead of 8, wouldn't I have been too low on my post-boil OG? Since 8 gallons boiled down to 5 put me at the gravity that I needed to be at...

Though, maybe there is a chance that the last 1.5 gallons of sparge was pretty watery anyway and doesn't add much gravity?

EDIT: The forum server clock is wrong and it put this post at the top of the thread. This should be below Wakadaka's post.

Click to expand...

It really doesn't matter. If you extract all the sugars that you are supposed to from the grains (limited to your mashing technique/setup/grain crush) then as long as you ferment out the correct post boil volume (which can be topped up with water after the boil if you end up boiling off too much) you will still end up with the correct OG. Why do so many people think that if they boil off too much they are screwed and will have too high of an OG.....just put some water in there guys...c'mon!