Collecting Extra Sparge Water to Top Off After the Boil

On my last AG batch, Northern Brewer's Dead Ringer, we lost more wort volume than I originally calculated due to a split boil.

The target gravity was 1.064 @ 5 Gallons and we ended up at 1.074 @ 4.2 Gallons.

-Would it have been advisable to have collected extra sparge water and kept on the side, to top off to 5 gallons?

-If I did collect the extra sparge water and kept it on the side for 1 hour during the boil, would it need to be boiled to sanitize?

Yes

I think you'd be better off adding plain water than more sparge water. Even if you control temp and pH, there comes a point where more sparge == more nasty.

There will also be the issue of proteins in the sparge water that wont be removed (as hot break) even if you boil it to sterilise (without a longer boil).

The amount of protein would probably be a lot lower than the main wort but could be significant - anyone know?

It might have been worth collecting some sparge water that you could add to the boil(s) earlier on if it starts to look like you might get too much boil off.

corax said:

I think you'd be better off adding plain water than more sparge water. Even if you control temp and pH, there comes a point where more sparge == more nasty.

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So did you have more boil off than expected? If this is the case I'd top up with plain water as you would more likely hit you OG target than adding extrat wort. Would seem about right too - 74 *4.2 / 5 = 62

I can only put 27 litres in my 33l kettle pre boil. So i put the excess wort from the sparge in a pot and boil it on my stove. When the main kettle start it's boil, I add the additional wort in my kettle and now can bring the boil volume very close to 33l.

mattd2 said:

So did you have more boil off than expected? If this is the case I'd top up with plain water as you would more likely hit you OG target than adding extrat wort. Would seem about right too - 74 *4.2 / 5 = 62

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Thanks to all for all of the replies. To answer the above, I ended up with more boil off than expected. My initial question was for future batches in case this happens again.

I'm now also wondering if I collect extra sparge water to put aside until after the boil and I don't boil that extra sparge water for an hour, but use it to top off in my fermenter if I will get DMS in my brew?

Based on the above with my future batches I'm leaning towards topping off with a little spring water if my gravity is high enough.

Is your pot large enought to add all the " extra" wort at the beginning of the boil? If you have excess wort at the end of the boil you can always can it and use it for future starters.

william_shakes_beer said:

Is your pot large enought to add all the " extra" wort at the beginning of the boil? If you have excess wort at the end of the boil you can always can it and use it for future starters.

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My main pot is a 30Q Turkey Fryer pot and my second pot is a 20Q stock pot. I use these two for my split boil. I also have a 16Q stainless steel pot which I planned to use to collect my extra sparge.

However I'm having second thoughts on if its worth collecting extra sparge water based on the replies I've gotten so far.

I have had to turn my flame down real low during the boil so I don't have as much boil off.

The easiest thing to do is take a gravity reading at the start of the boil. If you're OG is going to be low, add some DME at the beginning of the boil and top off with tap water at the end of the boil. If you're worried about infection from tap water you can boil separately, but I don't. The boil only removes water, not sugars, so you can deal with the SG at the start and the volume at the end. I have a DME makeup calculation on my brew sheet that I use for that purpose.

If you simply got too much boil off (i.e you hit all your target preboil volume and SG), then you want to just add sanitized water at top off. Adding additional sparge water is not necessary (and some would say is not advised due to pH, DMS, gravity, etc issues).

If you missed your target preboil volume or SG, and are concerned about getting all your numbers as close as possible, I would suggest a few things that can really help (if you don’t already have them, and don’t mind spending a couple more bucks):

1. Sightglass or some other method of measuring volume in your BK. This could be as simple as a long handled spool calibrated with marks at ½ gallon levels

2. Beersmith or similar brewing software – will really help you hit all of your numbers. You can adjust the boil off rate, time, volumes, in order to get an estimate of your final OG. That way you can adjust on the fly (add more water during boil, turn up burner to boil off faster, add DME) in order to hit your targets.

zyx345 said:

I'm now also wondering if I collect extra sparge water to put aside until after the boil and I don't boil that extra sparge water for an hour, but use it to top off in my fermenter if I will get DMS in my brew?

Based on the above with my future batches I'm leaning towards topping off with a little spring water if my gravity is high enough.

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I never boiled by top-off water, as our water is very good here and there isn't any chloramine or chlorine. If you normally treat your water for chlorine or chloramine, you'll want to treat your top off water also.

You won't get DMS from topping up with water.

Just start with more wort to begin with. If you can't fit it into the two pots from the beginning, slowly integrate it into the boil as you lose volume. Too much and you'll kill the boil, but a cup or so ever couple minutes is fine.

Bobby_M said:

Just start with more wort to begin with. If you can't fit it into the two pots from the beginning, slowly integrate it into the boil as you lose volume. Too much and you'll kill the boil, but a cup or so ever couple minutes is fine.

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Before I started doing a split-boil, I used to add in wort towards the end of the boil. Actually, I did this once and then I got paranoid about not boiling the wort for long enough. Anyways, is killing the boil a bad thing?

It's just that you're manipulating your hop utilization in an unpredictable way when the boil is knocked down. I'd rather ease the extra wort in between the final 20-15 minutes.