Doubling batch size, losing hoppyness and ibus

[patty the pirate]

Recently only just began brewing. Decided to go the BIAB route. Have had some success but one main issue I've had in two batches is that when I double batch size I lose a considerable amount of perceived bitterness and hop flavor/aroma.

First with a wheat ale and more upsetting with a very grapefruit forward ipa. Almost tasted like actual grapefruit juice.

I went from 5 gallons to 10 gallons. Followed original recipe, times, temps. Doubled grain bill and hops.
This current batch (already bottled) gave the aroma I was looking for during fermentation but lost it considerably after bottling.
I havnt found too much information on it but I have read that bitter hops should be taken down by 10% or so, which I didn't do. so I'm not sure where the issue lays.

I'm just curious if anyone else has had this happen or maybe I'm not considering something I should be.
Any advice is very much appreciated.

 

[eliastheodosis]

Welcome to the club! BIAB might be my favorite brewing technique. More information about your process might be helpful. Anything different between small and large batches for the cold side? My mind goes to oxygen getting in somewhere in the process for 10 gallons where it doesn't for 5 gallons. Maybe during fermentation or bottling. Other process differences between sizes could also matter here. The more info you give the better we can help

 

[hottpeper13]

I can't explain why, but when I went from doing 3 vessel to BIAB my hop utilization decreased. Maybe it's that the wort isn't clear running into the BK.

 

[pvtpublic]

I've gone from 5 gallons at a time to 155 gallons (not a typo) at a time. When you scale up, you're going to notice that you'll have to adjust something somewhere, for me it's dark malts.

 

[patty the pirate]

Welcome to the club! BIAB might be my favorite brewing technique. More information about your process might be helpful. Anything different between small and large batches for the cold side? My mind goes to oxygen getting in somewhere in the process for 10 gallons where it doesn't for 5 gallons. Maybe during fermentation or bottling. Other process differences between sizes could also matter here. The more info you give the better we can help

I'm think maybe oxygen. I switched from a 7 gallon carboy to a 15 gallon hdpe. I've read it's slightly permeable to oxygen so thus may be it

batches were mashed and boiled in same pot (13 gallon still pot), cooled in under 30 minutes using wort chiller. Pitched yeast and let it rip.
Don't have my notes on temps (at work right now).

When bottling I transfer to bottling bucket. With the 15g hdpe I transfered to another hdpe, and use a racking cane pushed through the airlock grommet to rack into bottle

Would the hdpe container cause too much oxygen exposure?
The 15 g hdpe Container was opened twice to check progress. And again to add priming sugar.

 

[patty the pirate]

I can't explain why, but when I went from doing 3 vessel to BIAB my hop utilization decreased. Maybe it's that the wort isn't clear running into the BK.

What does clear running into bk mean?

 

[patty the pirate]

I can't explain why, but when I went from doing 3 vessel to BIAB my hop utilization decreased. Maybe it's that the wort isn't clear running into the BK.

Probably meant brewing kettle right? It's mashed and boiled in the same pot. Using the BIAB method and using an engine hoist to lift the bag for sparging before the boil. So I'm unsure about what running clear means.

 

[eliastheodosis]

I'm think maybe oxygen. I switched from a 7 gallon carboy to a 15 gallon hdpe. I've read it's slightly permeable to oxygen so thus may be it

batches were mashed and boiled in same pot (13 gallon still pot), cooled in under 30 minutes using wort chiller. Pitched yeast and let it rip.
Don't have my notes on temps (at work right now).

When bottling I transfer to bottling bucket. With the 15g hdpe I transfered to another hdpe, and use a racking cane pushed through the airlock grommet to rack into bottle

Would the hdpe container cause too much oxygen exposure?
The 15 g hdpe Container was opened twice to check progress. And again to add priming sugar.

HDPE is more oxygen permeable than PET or glass, but I think that difference in oxygen ingress is probably negligible here. The other ways oxygen is getting into the beer likely have a much bigger impact. You can read into it some too. It can have an impact but I think it's relatively small. I've seen the difference discussed more often in the context of long-term aging beers where oxygen ingress over time can really matter.

What you said in your first message about the flavors falling off after bottling really make me think it's oxidation, though. The process changes seem to be a very likely culprit. Maybe there is more splashing when racking from the new HDPE container into this different bottling bucket. Maybe the HDPE container has a wider opening than the carboy and more oxygen is getting in when you open it each time. Maybe a combination of these. Overall, I would suggest analyzing both processes for ways oxygen could be introduced into the process. Splashing, exposure to the air, etc. Other threads from this forum could help with that. Try to reconcile any differences there and get your process for this new container as close to the old process as possible. See if it helps.

Probably meant brewing kettle right? It's mashed and boiled in the same pot. Using the BIAB method and using an engine hoist to lift the bag for sparging before the boil. So I'm unsure about what running clear means.

They were referring to wort running into the brew kettle. They are talking about hop utilization, though, so I'm not sure it's applicable to you losing hop aroma. Maybe I am missing something, though...

 

[hottpeper13]

With a 3 vessel system you vorlof until wort is clear then run it into the boil kettle.

 

[jerrylotto]

I use an HDPE fermenter (FastFerment) most of the time and have never had a problem with oxygen ingress as long as the lid seal was snug. I'd be much more suspicious of the bottling bucket. I do a closed transfer from my fermenter to a keg, individually dose bottles with sugar solution and bottle from the keg directly.

As far as doubling batch size goes, The difficult things to change are heat input and effective circulation often requiring more mash and boil time with home brewing equipment. Gravity is a good indication of completion of both mashing and boiling processes although iodine tests for residual starch are also useful for the mash.

 

[hotbeer]

Did each batch beers of the same recipe have the same actual OG within a few points?

 

[patty the pirate]

HDPE is more oxygen permeable than PET or glass, but I think that difference in oxygen ingress is probably negligible here. The other ways oxygen is getting into the beer likely have a much bigger impact. You can read into it some too. It can have an impact but I think it's relatively small. I've seen the difference discussed more often in the context of long-term aging beers where oxygen ingress over time can really matter.

What you said in your first message about the flavors falling off after bottling really make me think it's oxidation, though. The process changes seem to be a very likely culprit. Maybe there is more splashing when racking from the new HDPE container into this different bottling bucket. Maybe the HDPE container has a wider opening than the carboy and more oxygen is getting in when you open it each time. Maybe a combination of these. Overall, I would suggest analyzing both processes for ways oxygen could be introduced into the process. Splashing, exposure to the air, etc. Other threads from this forum could help with that. Try to reconcile any differences there and get your process for this new container as close to the old process as possible. See if it helps.


They were referring to wort running into the brew kettle. They are talking about hop utilization, though, so I'm not sure it's applicable to you losing hop aroma. Maybe I am missing something, though...

Thanks for the input. I'll have to think on that. There could have been more oxygen introduced during the transfer. I think I'll ferment in carboys until I get a larger container with a smaller lid or find a way to decrease oxygen exposure. The hdpe containers are pretty large (12 inches or so).they worked well with the red rye I recently made so maybe higher ibu beers should be reserved for the carboys.

 

[patty the pirate]

Did each batch beers of the same recipe have the same actual OG within a few points?

There was a difference. Don't remember the original Gravois there in my note but I do know the alcohol percentages. First batch was 5.1% and the second came in at 6.2%.
Would ~1% have a negative effect on hop flavor/aroma?

 

[patty the pirate]

Did each batch beers of the same recipe have the same actual OG within a few points?

I did some reading and this may be apart of the issue as well. The second batch is still good but maybe by hitting the high o.g. the malt and sweetness covered some of the hop profile. Thanks for pointing me in the right direction!

 

[Agent]

"The 15 g hdpe Container was opened twice to check progress. And again to add priming sugar."

If I was to point to any one thing - I'd say that 5 gallons of empty headspace on a vessel opened more than once would be it.

 

[hotbeer]

There was a difference. Don't remember the original Gravois there in my note but I do know the alcohol percentages. First batch was 5.1% and the second came in at 6.2%.
Would ~1% have a negative effect on hop flavor/aroma?

I did some reading and this may be apart of the issue as well. The second batch is still good but maybe by hitting the high o.g. the malt and sweetness covered some of the hop profile. Thanks for pointing me in the right direction!

You might be reading about bu/gu ratios. So you will see that if the specific gravity of the wort is changed then you should be adjusting the amounts of the hops for bittering to keep that same ratio.

If oxidation is the issue with your beers, then I would think that is something that you would notice in beer as it got older from it's bottling date. So if both batches seemed about the same hoppy taste just after bottling and the week or so you gave it to carbonate, but say a couple months later you noticed that hoppy tasted disappearing, then that might be oxidation. And perhaps you just noticed it with the bigger batch because you are having more of it stored longer before drinking it.

First with a wheat ale and more upsetting with a very grapefruit forward ipa. Almost tasted like actual grapefruit juice.

You don't like grapefruit taste?! That was one of the first things I strived to get in my beers when I first started brewing. I found that Cascade hops all by itself will give a intense grapefruit flavor to me. There are other hops too that are supposed to give that flavor note too. So if you don't like it, then you might need to change recipes. I think some if not many of us consider that grapefruit flavor a desired flavor in light ales and IPA.

 

[G_robertus]

Apart from BU/GU ratios (which don't say everything in my opinion), higher gravity will influence hop utilisation and result in lower bitterness. However, I also agree with the statement that you might notice oxidation the longer the big batch lasts. Higher ABV also results in better uptake of hop aroma in the beer, though the alcohol and malt flavour can also offset this. It's about finding balance. Still, it sounds like mostly oxygen to me. Bottling 10 gallons takes more time, so it gives you more time to oxidise your beer during transfer to the bottling bucket and when sitting in the bucket.

 

[patty the pirate]

You might be reading about bu/gu ratios. So you will see that if the specific gravity of the wort is changed then you should be adjusting the amounts of the hops for bittering to keep that same ratio.

If oxidation is the issue with your beers, then I would think that is something that you would notice in beer as it got older from it's bottling date. So if both batches seemed about the same hoppy taste just after bottling and the week or so you gave it to carbonate, but say a couple months later you noticed that hoppy tasted disappearing, then that might be oxidation. And perhaps you just noticed it with the bigger batch because you are having more of it stored longer before drinking it.



You don't like grapefruit taste?! That was one of the first things I strived to get in my beers when I first started brewing. I found that Cascade hops all by itself will give a intense grapefruit flavor to me. There are other hops too that are supposed to give that flavor note too. So if you don't like it, then you might need to change recipes. I think some if not many of us consider that grapefruit flavor a desired flavor in light ales and IPA.

Seems to be concensus, oxidation and failure to adjust the recipe accordingly. Thanks for the info.
I'll be going back to carboys for ipa's and adjusting hops based on abv to try to dial it back in. This is the first recipe of mine worth perfecting.

I think you may have misread my intent. The first batch was very grapefruit forward, practically actual juice. That's what I'm chasing lol

 

[Bobby_M]

One stage that may be picking up more oxygen is the fact that the beer will sit in the bottling vessel twice as long as you're filling bottles, because it takes longer to fill and cap bottles. Oxygen damage definitely kills hop aroma and flavor before it does anything else.

 

[ncbrewer]

One stage that may be picking up more oxygen is the fact that the beer will sit in the bottling vessel twice as long as you're filling bottles, because it takes longer to fill and cap bottles. Oxygen damage definitely kills hop aroma and flavor before it does anything else.

We're probably talking about an additional hour or so for the larger batch. I normally think of oxidation as being a slow process. Do you think this would actually make a noticeable difference? I'm really curious - it could change my attitude about oxidation.

As some background to my thinking: I had a batch where the auto siphon wouldn't work. I ended up dipping the beer out of the fermenter with a 2 cup measuring cup and easing it into the bottling bucket one dip at a time. That has to be one of the worst possible ways to transfer - I thought it would be a dumper. The beer ended up being fine. Apparently, the yeast stripped the oxygen from the beer. It wasn't a hoppy beer, so it doesn't answer the question about how much it can strip out, but I was still really surprised that it worked out that well.

 

[doug293cz]

I normally think of oxidation as being a slow process.

Oxidation takes place at different rates, depending on temperature, the amount of dissolved oxygen, and the compound being oxidized. In most cases oxygen is absorbed faster into the beer than the oxidation process itself. This means you can pick up enough O2 to damage the beer in a much shorter time than it takes for the oxidation damage to be detectable.

Brew on

 

[ncbrewer]

Oxidation takes place at different rates, depending on temperature, the amount of dissolved oxygen, and the compound being oxidized. In most cases oxygen is absorbed faster into the beer than the oxidation process itself. This means you can pick up enough O2 to damage the beer in a much shorter time than it takes for the oxidation damage to be detectable.

Brew on

I didn't know that, but it's consistent with the fact that yeast consuming sugar helps strip oxygen from the beer before it has a chance to oxidize.