Seems like ALOT of water lost during boil

[jerryodom]

So today was our first go at all grain brewing. We did a 5 gallon batch for the sake of figuring out of all the details.

First of all I'll be doing 10-15 gallon batches from now out just to make it worth the time! It was far more work than the malt extract with the whole mashing/lautering process. But it was fun!

The big issue was that we put 6 1/2 gallons to the boil and when we poured it in to the fermenter we had about 3 1/2 gallons left! So that much evaportated during the cooking process?? Does this sound right to you guys? We added water to bring the amount of wort up to 5 1/4 in the fermenter and the OG was about spot on which makes me feel like we probably did right.

We *almost* have a clue what we're doing.

 

[Yeast Infection]

How long did you boil for....what was the weather like, humid or dry out, do you live at elevation, did you have a rapid boil, or a mellow boil, is the surface area of the wort big or small. All of those things can drastically affect evaporation rate.

I live in Colorado, at 5400 ft elevation and it is a dry environment and my evaporation rate is about 15% per hour, which is on the high end.

Im guessing that you also do not have the most accurate measure of how much wort there is at the beginning of the boil. I know i dont, but i have done it enough times to know where the wort level needs to be.

 

[knarfks]

I'm kind of doubting you actually had 6.5 gallons. Did you account for dead space in mash tun, boil off, trub loss, grain or absorbtion? My first couple of all grains were the same way with about 4 gallons in the fermenter, but after tweaking it is now 5.25 or 5.5 gallons.

 

[Iordz]

Evaporation rates have a few variables. The largest being the intensity of the boil, second being the diameter of the oiling kettle. You could try turning the heat down until you have a gentle boil next time and see if that helps. My system evaporation rate is 20% because I have a wider pot, so I just adjust the recipe for the predicted boil-off. Once you know your system a little better you will be able to adjust the variables and predict the final result.

 

[D2T]

I had a similiar experience with my first boil using my Banjo burner. I had quite a boil going and have since realized that I only need a bare minimum of flame to keep the boil going and I lose a lot less water.

 

[Axegod]

I had a similiar experience with my first boil using my Banjo burner. I had quite a boil going and have since realized that I only need a bare minimum of flame to keep the boil going and I lose a lot less water.

Same thing with me...I lost well over 15% for my first few boils...and then lost more due to the trub......after 6 AGs, I have finally figured out all my equipment.

Ease off on the full gas when you start to boil, and you should be fine.

Cheers.

 

[jerryodom]

We actually accounted pretty well for the amount of wort we were able to get out of the masher. Using a gallon pitcher we filled it 6 1/2 times through the course of the sparging process. We live in Baton Rouge, Louisiana so as always it's humid.

Now we were boiling with a pretty big crawfish pot that was considerably larger than the amount of wort we used.(I want to say it's 140 quarts) The boil may or may not have been the problem. I thought I had it at a fairly easy pace but since we lost so much I guess not. We didn't cover the pot while it cooked?

I think you're probably right Iordz. Seems like since there was so much more surface area for with this setup we'll have to account for that next time.

All is well if OG is well I hope?

 

[Yooper]

It sounds wrong to me to lose 3 gallons in the boil. I can't imagine how. I painted the gallon marks on my pot, and so I can see how much my runoff is. I usually lose about a .75 gallon an hour and that's at a full boil. Are you 100% sure you had 6.5 in the kettle to start? That sounds like it's not even possible, but I guess anything is possible!

Edit- I see you were using a pot with a larger surface area, so that's probably it. But, even though you filled a gallon pitcher 6 1/2 times, it doesn't mean you had 6.5 gallons! I lose about a gallon to lauter tun deadspace and grain absorption. You need to measure your wort AFTER you sparge and combine that with your first runnings.

 

[Iordz]

That's funny, because I also have that burner! It's great but really powerful, so I have to turn it down a lot. Like I said, once you know your system, you can just improvise.

 

[jerryodom]

Hell I suppose we could've been off by at most a gallon.(at the very most) I wish the pot was here so I could get the diameter.


The way we measured how much liquid was in the pot was to drain the wort from the sparge/lauter tun in to the gallon jug and then pour it in to the pot. We'd extract a gallon of wort then pour back in a gallon to the tun. Soak for 12 minutes and then extract again until we had 6 1/2 gallons.

I suppose we'll figure it out here before long but I didn't even anticipate this! Have to watch that flame next time I guess. We'll see how it comes out.

 

[SW Brewer]

BYO has a recent article on this on their website:

http://byo.com/departments/1638.html

Greg

 

[dcunitedfan]

3 gal does sound like a pretty extreme evaporation rate - others on this forum have already covered the bases of things to try to reduce that.

With the wisdom of mutual hindsight, I'd suggest making whatever burn rate/heat shield/etc procedure changes, doing say a 30min test boil with water, and checking your evap. rate. I say this because...

When I first got my big kettle and wort chiller (late last month), I did a dry run, boiling just water - but I did that mostly to experiment with the wort chiller, not to measure my evap. rate. I should have done that too - as it turned out when it came time to do my first batch, I came in well under volume. I started with the same 5.5 gal that worked well with my stovetop extract brewing setup, and of course the evap rate is a lot higher when you're boiling the entire volume for 60min. I ended up at about 4.5 gal when I went to the fermenter. (I suspected something was amiss when I saw how far the water line had dropped during the boil). I quickly boiled, cooled, and poured about 0.5gal of water after pitching but before fermentation had begun. It seems to have come out to the right volume and OG/FG, and when I transferred to a secondary fermenter it tasted great (for a green beer) so I think that I avoided oxidizing it.