Losing wort in boil

Just did an APA this past weekend and ended up boiling 6.5 gal down to 4.5 in 60 min (I have a 7 gal kettle). I have had problems with this in the past and just said screw it. It really does not seem like I am boiling too vigorously...it is just barely rolling. Any suggestions?

Is there anything that happens to hop bitterness if I top it off to 5 gallons?

Thanks,

SM

Two things will reduce your ending volume. Boil off, which you are probably accounting for and expansion/contraction which you may not be accounting for. Depending on the temperature when you measure your 6.5 gallon starting volume you may loose significant volume when cooled.

Interesting. Basically what I am doing is hitting the flame on after I collect approx 4 gal....just to speed things up. Am I to believe that this is expanding the wort and when I think I'm at 6.5 I stop my runoff, I'm actually much less???

I had the same problem with my new burner but had other issues because of wind so I had to keep it on high the entire boil. I Started damn near the top of the kettle and ended up with maybe 5 and a half gallons before I had to stop because of the hops/cold/hot break sludge. Probably lost half a gallon to that.

smarek82 said:

Interesting. Basically what I am doing is hitting the flame on after I collect approx 4 gal....just to speed things up. Am I to believe that this is expanding the wort and when I think I'm at 6.5 I stop my runoff, I'm actually much less???

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Your wort will "shrink".

This is the same principal that makes thermometers work...

I think the kinda universally accepted number is 4% if you are going from boiling to 68f.

Depending on how hot it is when you measure your original volume, you should count on loosing a quart or so to contraction.

Most of your loss will come from evaporation and the rest would be dead space in your kettle (the amount left behind if you use a siphon tube), any left is hoses, chillers, etc.

Evaporation will vary with temperature, humidity, wind, etc... but for the most part, these losses are fairly constant. You should be able to account for it in future brews once you go through a couple brews and "calibrate" your losses.

I'm following now. Basically I'm screwed because I only have a 7 gal kettle and honestly if i filled it up any more, it's going over.

Dead space isn't really an issue. I just pour my wort into primary through a strainer.

If there was only a way to control evaporation

smarek82 said:

I'm following now. Basically I'm screwed because I only have a 7 gal kettle and honestly if i filled it up any more, it's going over.

Dead space isn't really an issue. I just pour my wort into primary through a strainer.

If there was only a way to control evaporation

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There is a way, but you don't want it (Don't cover the kettle during the boil).

There is another option...You can add water during the boil to replace what's evaporating.

Most folks that do partials top off post chill thus adding un-sanitized water to their cooled wort (some boil their top-off water).

If through, experimentation, you know you are going to be 1/2 gallon short at the end of your boil, just add it prior to the last 15 minutes. If you dump 1/2 gallon in at one time, it will kill your boil, so I would do it gradually. Maybe even use it in the "Boil Over Fight", just add a little extra.

smarek82 said:

Is there anything that happens to hop bitterness if I top it off to 5 gallons?

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Getting back to one of the questions that has not yet been answered.

Diluting your wort with water dilutes everything about it (color, gravity, hop bitterness/flavor/aroma).

Since you ended up with less wort than you expected to have, this means that all of these things above are most like higher than you intended. Diluting with water will bring them all back to where you wanted them to be.

Great point Ed...I do remember from that first and only extract batch I did, I ended up topping off with bottled spring water(presumably sanitized).

Will my IBUs be altered because of adding the water?

I would think NO because by having a higher OG than was anticipated actually decreases IBUs from what I orininally intended.

Sorry for the questions and you have been a huge help, but what do you suppose would happen if I were to add the extra 1/2 gallon of sanitized water to the secondary after fermentation????

Walker said:

Getting back to one of the questions that has not yet been answered.

Diluting your wort with water dilutes everything about it (color, gravity, hop bitterness/flavor/aroma).

Since you ended up with less wort than you expected to have, this means that all of these things above are most like higher than you intended. Diluting with water will bring them all back to where you wanted them to be.

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Ding Ding Ding. We have a wiener.

If you dilute the concentrated wort back to the target gravity, you will dilute all of the beers consituents to the target levels. It similar in pricipal to pre-hopped extracts.

Dilution calulators can help crunch out the mystery.

smarek82 said:

Will my IBUs be altered because of adding the water?

I would think NO because by having a higher OG than was anticipated actually decreases IBUs from what I orininally intended.

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Hop utilization is not affected by gravity unless your gravity is SIGNIFICANTLY higher than intended. If you are off by just a few points, the IBUs will not have been impacted by this.

This is based on my playing around with ProMash and upping the gravity of a recipe until I started to see a noticible decrease IBUs.

edit: your logic is a little backwards, too. If the higher gravity caused IBUs to be lowered, then adding more water will make the final IBUs even lower than that.

I would plan the hops based on a full boil (regradless of your kettle size) and add water during the boil to make up for evporation. The hop utilization may be off very slightly, but your only talking about 1/2 gallon or so of water anyway.

I would not add water to the secondary.

The order of my choices would be;

1>) Full Boil
2>) Add makeup water during boil
3>) Add makeup water post boil into primary
4>) Look REAL hard for a bigger kettle

Maybe someone has a good reason why this is a bad idea and no one suggested it yet (my beer seems to taste fine...), but i have a 6 gallon pot i do outside on a turkey fryer and a 2 gallon stockpot that i do inside on my stove top. Boil like normal, i eye-ball split my additions between the two pots, and mix them together @ cooling time. By the time the boils done, they've both reduced enough to fit in the 6 gallon pot and it goes EXACTLY to the top with my wort chiller in there. I vote 2 pots if you can't get a bigger kettle.

markg388 said:

Maybe someone has a good reason why this is a bad idea and no one suggested it yet (my beer seems to taste fine...), but i have a 6 gallon pot i do outside on a turkey fryer and a 2 gallon stockpot that i do inside on my stove top. Boil like normal, i eye-ball split my additions between the two pots, and mix them together @ cooling time. By the time the boils done, they've both reduced enough to fit in the 6 gallon pot and it goes EXACTLY to the top with my wort chiller in there. I vote 2 pots if you can't get a bigger kettle.

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You might have a very small difference in hop utilization if you don't split the hops to the correct ratio, but probably no issue at all.
If you have way more extract (I'm assuming you are doing extracts) in one pot than the other, it could make a small difference, but you said you're splitting at the correct ratio, so again probably no problem.

The only real problem I see is keeping your eye on 2 BK's at the same time or else extending the total time required by having to boil twice.

If the OP is doing 5 gallon batches, he is only missing is post boil volume by 1/2 gallon. Personally, I wouldn't risk a boil over (taking your eye off the bk), or extend the brew day for an additional hour to make up 1/2 gallon.

Two pots would not work because run-off after about 5 gal is nearly at 1.010....there wouldn't be hardly any hop utilization with the wort in the smaller pot.

Eventually I will splurge for a larger pot, but until then I will add water during the boil, especially if I want to do 90 min boils.

BTW someone had mentioned dilution calcuators...anywhere online I can find them???

Thanks,

SM

I have the same issue - I have a 7.5 gallon kettle with a 20%/hr boil off rate. I just scale all my recipes for 4.75 gal which is what I end up with at the end of the boil. I usually end up with around 4-1/2 gal in the fermentor after straining and cooling. One nice thing about that is you don't have to worry about blow-offs!

Some day I'll get me a bigger boil kettle, but until then...

I have to start off with 8 gallons to end up with 5.5 in the fermenter.I think the hops absorb a lot of wort in addition to boil off and shrinkage.