Finishing with less beer than expected - why?

[njohnsoncs]

My last few brews have been extract kits and I have topped off with water to get 5 gallons in my primary fermenter. After bottling, I keep getting between 4 and 4.25 gallons of beer. Where is the other 0.75 - 1 gallon going? Is it all left behind in the trub? I do take about 2-3 gravity readings which is about 6 ounces at a time but this would only explain at most 0.15 gallons.

 

[Incubus2112]

How big is your boil kettle?

 

[njohnsoncs]

5 gallons and, yes, I do lose wort due to evaporation during the boil but I top off to 5 gallons after I cool the wort and transfer to the primary. So at the beginning of fermentation I have 5 gallons but after bottling I have almost a gallon less...

 

[Dcpcooks]

5 gallons and, yes, I do lose wort due to evaporation during the boil but I top off to 5 gallons after I cool the wort and transfer to the primary. So at the beginning of fermentation I have 5 gallons but after bottling I have almost a gallon less...

Your losing beer to trub, hops and yeast in the fermentor. Do you have a 6.5 gallon carboy? If so you you can go with 5.5 gallons in the fermentor. Are you hitting your OG numbers or are you a little high?

 

[Silver_Is_Money]

People underestimate (or fail to estimate at all) the amount of water that is carried out through the airlock by roughly 300,000 carbon dioxide bubbles, wherein each bubble is fully water saturated.

To end up with 5 gallons you must start with more than 5 gallons to account for this, plus trub loss, plus equipment dead-space loss, plus hydrometer check losses.

 

[njohnsoncs]

Your losing beer to trub, hops and yeast in the fermentor. Do you have a 6.5 gallon carboy? If so you you can go with 5.5 gallons in the fermentor. Are you hitting your OG numbers or are you a little high?

After topping to 5 gallons, my OG is right in the middle of the range specified by the recipe. I could try to top to 5.5 gallons as long as my OG is still OK.

I'm surprised almost a gallon can be lost to just the trub and gravity readings. If this is what is happening and is expected that is OK - as long as it's nothing I'm doing wrong.

 

[flars]

Have you marked the 5 gallon level on your fermentor with a measured amount of water? Asking because factory markings are often inaccurate. As @Dcpcooks has said you can add a half gallon for trub loss. May result in a little ABV loss, but most likely not noticeable.

 

[Incubus2112]

5 gallons and, yes, I do lose wort due to evaporation during the boil but I top off to 5 gallons after I cool the wort and transfer to the primary. So at the beginning of fermentation I have 5 gallons but after bottling I have almost a gallon less...

This is your answer. I suggest going to a full 10 gallon boil kettle.

The reason is this: You are ALWAYS going to need more space than your batch size. So, for a 5 gallon batch, you need to have bigger than a 5 gallon brew kettle to be able to come in at 5 gallons at the end.

 

[Dcpcooks]

After topping to 5 gallons, my OG is right in the middle of the range specified by the recipe. I could try to top to 5.5 gallons as long as my OG is still OK.



I'm surprised almost a gallon can be lost to just the trub and gravity readings. If this is what is happening and is expected that is OK - as long as it's nothing I'm doing wrong.

I doubt your doing anything wrong. You can cold crash or give it a little more time in the fermentor to let trub compact a bit more. You can also add a bit of DME to the batch if you gravity is a bit low.

It's always a good idea to have a little extract or dextrose on hand to boost gravity if needed.

 

[GrimBrewer]

1 gallon sound a bit high to lose on trub. Next time measure out your trub.

After moving your beer to bottling bucket add 1/4 gallon of water to the trub. Sake it about and then measure the sludge.

I can get about 1liter of trub out of 10. I do sif out most of the solids after boiling and cooling, so its mostly hop material.

 

[Dcpcooks]

This is your answer. I suggest going to a full 10 gallon boil kettle.



The reason is this: You are ALWAYS going to need more space than your batch size. So, for a 5 gallon batch, you need to have bigger than a 5 gallon brew kettle to be able to come in at 5 gallons at the end.

It's very common to top off extract kits. He doesn't need a bigger kettle with that process. He's not losing wort in the kettle, he's losing it in the fermentor.

It's nice to do a full batch boil. He'd probably get better hop utilization and wouldn't have to deal with top off liquor. That said his method is common and can make good beer.

 

[Incubus2112]

Just a suggestion as this was something that I found myself encountering as recently as a few months ago. I worked my way around it by getting a bigger kettle.

 

[SlitheryDee]

For me it's all trub loss. I leave a tiny bit of beer on the yeast in the carboy so I can more easily harvest, and then I lose a little bit in the bottom of the bottling bucket that I really don't want due to the particles that are usually present in it. Then there were the two or three gravity measurements that I did in the course of fermentation, It probably amounts to a little more than half a gallon all told. I find that beersmith accounts for the losses pretty accurately, so I end up with more or less what I thought I would at bottling time.

 

[balrog]

@flars has a very important point -- have you REALLY measured well, both the fermenter and bottling bucket markings (if used)? You will find them sort of close but easily off by a quart or more, especially at the 5G levels.