A Gallon Short

[Buell]

I done messed up.

Brewed a 5gl IPA BIAB recipe last weekend and realized after I pitched the yeast that I had missed my water calculations and only had 4 gallons in the fermenter...

What can I expect from the finished product? A “stronger” tasting beer with a higher than expected IBU and ABV?

Will know for sure in a couple of weeks I guess.

 

[Rob2010SS]

I suppose this depends on what kind of numbers you ended up with. Did you end up with expected OG on your 4 gallons or did you end up with a higher OG on your 4 gallons? If you were planning on an OG of 1.055 and ended up at 1.055 but a gallon short, you're really going to have the same beer, just less of it. If you planned on OG of 1.055 and ended up with 4 gallons at 1.075, your water volumes were miscalculated and you'll end up with a stronger version of what you were trying to make.

 

[Buell]

Oh, I did leave out that info.

My target OG was 1.70, but I overshot that and hit 1.80.

 

[beermanpete]

Your beer will be stronger with more focus on the malt and less hop flavor that intended. It will likely be ok, just not what you were aiming for.

 

[micraftbeer]

Once in the past when I overshot my OG on a beer I was specifically trying to be on the lighter side, I added water to the fermentor. It turned out fine. But I think if it happened again, I'd just let it ride.

At 1.080, you're talking a pretty big beer. I personally would be a bit scared of that and would try to add some water. You have to do some basic algebra to figure out how much water to add. If you added 1 gallon, it would be something like this:

(1 gallon x 1.000 OG) + (4 gallon x 1.080 OG) = 5 gallon X ? OG
? OG = 1.064

So you'd undershoot your target there. If you added a 1/2 gallon, you'd end up with 1.071. But if you aren't afraid of the 1.080, I'd just leave it.

 

[beermanpete]

The calculations are typically done with "gravity points". ((80/70)*4)-4=0.571. To get to the target gravity of 1.070 an additiona 0.57 gallons of water is requierd. This indicates the gravity would have been short if the 5 gallon target had been met. I would not bother making an adjustment at this point. Let it ride. It will be fine. If you took notes during the brew day you should be able to figure out what went wrong and make an adjutment on the next batch.

 

[Buell]

Thanks for the responses but now I have gone from not being concerned to being concerned.

My first thoughts were - no big deal.

Then I went to - meh, just need to add hops to overcome the stronger malt flavor.

Then when beermanpete said I would have missed my OG anyway - I became concerned. I ground my grain to a really fine crush and but obviously that wasn't enough. Don't know what else to do to increase efficiency and hit OG target.

 

[FatDragon]

Efficiency varies from system to system. What was your mash efficiency target?

At a higher gravity, efficiency tends to drop a bit, so you might have lost a couple points simply because you used less water.

Did you stir a couple times during the mash? That can give you a few more points.

I do a sparge step in my process (also BIAB), which also gives a few more points. There are various ways to do a BIAB sparge, from dunking the bag into a bucket with the sparge water, to pouring the water into or over the bag while it's draining over the kettle or sitting in a bucket. For mine, I have a bucket with a bunch of holes drilled in the bottom which nests into another bucket, then I open the bag and pour water over the grains, making it more like a batch sparge over a false bottom than anything else.

 

[baldm79]

Thanks for the responses but now I have gone from not being concerned to being concerned.

My first thoughts were - no big deal.

Then I went to - meh, just need to add hops to overcome the stronger malt flavor.

Then when beermanpete said I would have missed my OG anyway - I became concerned. I ground my grain to a really fine crush and but obviously that wasn't enough. Don't know what else to do to increase efficiency and hit OG target.

What % efficiency were you aiming for? It’s not uncommon for biab to be a little low as far as I know.. probably nothing to worry about.

 

[beermanpete]

Hitting the target gravity should be as simple as using a bit more grain.

 

[Buell]

I haven't been brewing very long but when I first started I read a million things on calculating effeincey and just confused myself, so I gave up on trying to calculate it.

I have missed my recipe OG target the last brew or two so this time I milled the grain much finer than before, hoping that would help.

I stir really well when adding the grain to the water and then again after the 60 mash. No sparging but I squeeze the bag well.

This was the first time I have tried this recipe, I think next time I'll up the grain bill a pound.

And add the correct amount of water...

 

[micraftbeer]

If you don't have one, I'd definitely recommend getting a refractometer. For all-grain brewing, I think it's an essential tool if you want your recipes to hit your gravity numbers. BeerSmith will tell you what your pre-boil volume should be and your pre-boil gravity. While you're letting your grains drip out, you stir up the kettle and take a eyedropper sample of wort and check the gravity with the refractometer.

If your gravity is higher than what your pre-boil gravity should be, you pour some water through your soaked grain bag. You'll get some amount of gravity higher than if you were just pouring the water directly into your kettle. Of course it works better if the water is hot, and you might not have heated water sitting by, but even room temperature water will get some sugars washed down with it.

If your gravity is lower than expected, you immediately stop dripping anything further from your grain bag into your kettle and start contemplating extending your boil time. Boil off more water so you get your OG lower.

A refractometer lets you do these adjustments on the fly. Just remember to stir the wort up good before grabbing your sample. I've been burned by that detail before...

 

[BongoYodeler]

Meh, it'll be beer. Drink it, but be more careful next time. Cheers.

 

[MapleGroveAleworks]

Just mill your grain the same way each time. Brew a batch. Calculate what your efficiency was:

https://www.brewersfriend.com/brewhouse-efficiency/

Then set your next recipe to that efficiency number. Use that going forward.