Acceptable percentage of top off water in fermenter

[dude1]

I brewed a relatively large BIAB batch (15 Gal) of a light beer, which means, even with a quite thin water to grain ratio (~1.5qt/lb), the amount of mash water was much smaller than the batch size.

After chilling and transferring, I ended up with 8.2 Gal and added 7.2 Gal to get to 15.5 Gal, which should give me my packaged 15 Gal.

That's nearly 50% top off water.

I just wanted to know if this is normal for light beers or if I can expect problems.

Thanks

 

[wilserbrewer]

It all depends on how much fermentables you can capture with your “small” mash volume.

You would have been well served to take a gravity reading of your wort prior to topping off with water.

If your 7.2 gallons was at 1.080 and you top off to 14.4 gallons your new gravity would be half, or 1.040.

My guess is that you added way too much top off and you have an extremely light beer, almost invisible beer.

Best not to top off blindly, taking a gravity reading will let you know where you’re going.

As far as an acceptable amount to top off, one can’t really answer you’re question without knowing your post boil volume and gravity, and your desired post top off gravity.

And for the record, it was not nearly 50% top off water, it was 57% top off water. Likely way too much...guessing.

Did you take gravity readings? That would let you answer your question.

 

[dude1]

Thanks

The only gravity I measured was the one after adding water and it was still 1.053

So, not too bad, and hopefully I won't end up with 60 bottles of water.

 

[wilserbrewer]

That’s pretty high....how much total grain did you use?

 

[dude1]

27.75lbs

 

[wilserbrewer]

Well, you either did an excellent job and got an outstandingly high gravity or didn’t mix the top off water in thoroughly and have a false gravity reading. My gut tells me the latter, but likely a number cruncher will be waking soon and give you a better answer as to if your 1.053 gravity is even possible.

 

[dude1]

Yeah

The water to grain ratio was pretty high, I sparged quite a lot and squeezed the bag a lot as well, so hopefully the reading was quite accurate.

I'll keep you posted in a couple of weeks to see how this beer is doing.

 

[Miraculix]

Around 81% efficiency, based on the assumption of the malt being mainly two row.

I get similar results with my system and similar top of water / wort ratios , you got a very good efficiency and your beer should be fine!

 

[dude1]

Also, the pH was perfect

Grain bill was:

78.7% Pilsner
8.4% Carapils
7.1% Munich
5.7% Vienna

So, yeah, very fermentable malts globally

 

[wilserbrewer]

I sparged quite a lot .

Ok good on you, I missed this the first time through.

 

[dude1]

Just as a follow-up: the beer indeed turned out too watery.
I'll mash with more water next time, sparge more and avoid adding to much to the fermenter.