Messed up mash water calculations

I had used http://www.brew365.com/mash_sparge_water_calculator.php a few times before to calculate my mash water and strike temp. It had seemed to work, but this time it was way off.

I was brewing what should have been a nice dubbel, but ended up with over six gallons in the fermenter with a o.g. of 1.050 instead of 1.060.

This is what I used:

8.76 total water
3.36 Mash Water
5.40 Sparge water
165.56 Strike Temp
6.37 Pre-boil wort volume

I'm kind of figuring that I do usually have 6.4 gallons or so when I boil and end with a little over 5. But in this case, I had close to 6.5 gallons in the fermenter. I ended up pouring a gallon into a second fermenter because I had already chilled it (and pitched the yeast) when I completely understood my dilemma.

How do I set up my calculations so that this doesn't happen again? What would I have done to 'fix' this?

And oh yeah, this was my first batch for which I had done a starter.... I am quite upset at how this batch turned out on its way into the fermenter.

Lots of things to take into consideration, if you provide the recipe, grain bill and your process of water additions we can help you out.

Things to consider:
Grain absorption
Dead space
Boil off
Kettle loss
Mash water volumes
Accurate volume measurements

10 lbs belgian pale
0.5 lbs Belgian Carmunich
.25 lbs Belgian Special B

I created the mash with 3.5 gallons of strike water, and then after the saccharification was done, I did a continuous sparge by hand with 5.40 gallons of water.

In a recent batches, I used 9 gallons mash water total and got the right volume. This one called for 8.76 and I way overshot. The only conclusion I can come to is that I must have mismeasured somehow and had a full gallon extra.

I haven't yet calculated all the particular volumes and losses, I am only about 5 batches in on all-grain, but here are the values I used on the last batch that worked:


Batch Size (gal): 5 gallons
Grain Bill (lbs.) :12.75
Boil Time (hrs.): 1
Trub Loss (gal.): .5
Equipment Loss (gal.): 1 gallon
Mash Thickness (qts/lb.): 1.33
Grain Temperature (deg.): 70
Target Mash Temperature (deg.): 149

Constants
Wort Shrinkage (pct): 4
Grain Absorption Constant (gal/lb): .13
Percent Boiloff per Hour (pct/hr): 10

Results
Total Water Needed (gal.): 9.02
Mash Water Needed (gal.): 4.24
Sparge Water Needed (gal.): 4.78
Strike Temperature (deg.): 161.00
Pre-Boil Wort Produced (gal.): 6.37

All of the calculation based on the recipe are correct and so is the math so I can only assume you did not measure something properly to receive the greater volume. In the future use a calibrated stick to measure your pre-boil volume. If you wind up with too much you can then boil longer to drive off the extra water and achieve the correct volume and gravity.

So if I am going to do a long boil to drive off water, I assume that I boil until I get to my standard pre-boil volume and then start the usual timers? Will there be undesirable effects on the beer such as over caramelization or darkening?

tkrafty said:

So if I am going to do a long boil to drive off water, I assume that I boil until I get to my standard pre-boil volume and then start the usual timers? Will there be undesirable effects on the beer such as over caramelization or darkening?

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Yes, you boil until you hit pre-boil volume, then start the timer.

As to your original predicament, I think you must have mis-measured along the way as there's no way you didn't boil off any (actually added) liquid.

tre9er said:

Yes, you boil until you hit pre-boil volume, then start the timer.

As to your original predicament, I think you must have mis-measured along the way as there's no way you didn't boil off any (actually added) liquid.

Click to expand...

+1 and yes you may get a little darker color and carmelizatuin but it shouldn't be a problem, people do 90 minute boils all the time