NEIPA has Diacetyl after cold crash

[mcinnes01]

Hi

Just looking for a little advice, I'm fairly new to brewing but have had an issue with oxydation in my last 2 brews, not sure if this has been a Diacetyl related issue or the fact I just co2 purged my kegs rather than fill with sanitiser then purge (which is what I'm going to do this time). I do a closed transfer to my kegs and push the beer out of the fermenter with CO2. I tend to brew a NEIPA style and I'm using an SS brewtech Chronical fermenter with domed lid and then I let the fermenter bubble through a mini keg of sanitiser and then top off with CO2 after sampling and dumping yeast to ensure I don't have oxygen pulled back in to the fermenter. The mini keg just acts as a little CO2 harvester in case I get any back pressure.

I've got my latest batch in the fermenter currently, I did have a little issue with a temperature rise during the high krausen as I was away and didn't have my chiller hooked up, but other than that it fermented well, I had it at around 21c for the final few days for a D rest before cold crashing for 3 days, but I just pulled a sample to do a Diacetyl test before kegging and I've got the dreaded butterscotch smell and taste.

I assume there has been a bit of hop creep, this beer has around 14g/l of dry hops.

I've done a fair bit of reading around the forum and there is some suggestions of warming back up to say 19-21c for 3-7 days and others have mentioned adding more yeast and sugar/DME in order to get a Krausen again. Just not sure how to do with without introducing oxygen in to the beer.

I also have dry hopped in 2 hop filters just to make crashing the beer and filtering a little easier, but I wanted to keep my hop exposure as short as possible. It's been 6 days now, but if I warm my beer back up and potentially crash again I'm looking at another week or more of hop exposure.

Many thanks

Andy

 

[VikeMan]

I would go with the "warming back up" crowd and see what happens. As you have figured out by now, the time for a diacetyl test is before crashing. But at least you haven't packaged yet. Yes, if you do this, your hops are going to be in the beer for a longer period, but I'd say that's probably better than the diacetyl.

 

[mcinnes01]

Great thanks, do you think I need to add more yeast/sugar? My beer already over attenuated as it was meant to finish around 1.024 and it was down to somewhere between 1.018-1.02 hence my thoughts around hop creep.

 

[VikeMan]

Great thanks, do you think I need to add more yeast/sugar?

IMO, usually not. But you could try krausening if simply warming doesn't work.

My beer already over attenuated as it was meant to finish around 1.024 and it was down to somewhere between 1.018-1.02 hence my thoughts around hop creep.

First, yes, diacetyl can be a side effect of hop creep. But... If your beer really should have finished at 1.024 and actually finished at 1.018, I'd say there's more than hop creep going on. Hop creep adds gravity that gets fermented, but the FG should not change very much.

 

[mcinnes01]

I've had most of my beers over attenuate, I wondered if it was the temperature of my grain bed, but I've been stirring quite a lot whilst mashing and checking with another temperature probe to rule that out. I wondered if I wasn't getting the amount of dextrin extracted that I expected on my recipe, which I guess could still be the case, or my gravity reading is just off. To be fair the current gravity is from my iSpindle but I calibrated before and when I measured the OG it was within 0.001 of my hydrometer.

I did a stepped mash this time with protein rest at 50c, mashed at 63c and then mashed out at 75c to get alpha and beta amalyase rests.

Is there anything else you are thinking in the "more than hop creep going on"? Infection wise I'm fairly militant with sanitising everything brewzyme after every brew day or when I empty the fermenter and then star san right before I brew both hot and cold side. I've not noticed any other off flavors and I had a really good beer in plastic fermenter 4 brews ago, followed by an oxidised one in the plastic fermenter and then I moved to my stainless ss brewtech fermenter and got a really oxidised one, and hence this one I've done a lot of research and tried to mitigate oxygen pickup, dry hopped for less time and used dry hop filters and ensured I had no back pressure when sampling or dumping trub during cold crash.

Also is there a way to know if my beer is krausening in my sealed fermenter once it's warmed back up or will I need to pop the lid?

Many thanks

Andy

 

[Dgallo]

First, yes, diacetyl can be a side effect of hop creep. But... If your beer really should have finished at 1.024 and actually finished at 1.018, I'd say there's more than hop creep going on. Hop creep adds gravity that gets fermented, but the FG should not change very much.

This actually depends on a few things. I’ve seen 8 point changes personally with hopcreep with a large dh load and warmer temps in 4 days, so (1.018-1.010) it’s certainly possible. 4 points is more typical though.

That said I do agree that the op should warm back up to 70-72 and rouse the yeast if possible.

 

[VikeMan]

To be fair the current gravity is from my iSpindle but I calibrated before and when I measured the OG it was within 0.001 of my hydrometer.

If in doubt, I would recommend checking with a regular hydrometer. Especially since you say that most of your beers seem to over attenuate.

Is there a way to know if my beer is krausening in my sealed fermenter once it's warmed back up?

I'm not sure what you're asking. Warming the beer back up just allows the yeast to get active again, hopefully absorbing the diacetyl. There's no new fermentation/krausen involved. "Krausening" would be the addition of fermenting wort that is at high krausen. That would be worth trying if simple warming doesn't work.

 

[mcinnes01]

I'm not sure what you're asking. Warming the beer back up just allows the yeast to get active again, hopefully absorbing the diacetyl. There's no new fermentation/krausen involved. "Krausening" would be the addition of fermenting wort that is at high krausen. That would be worth trying if simple warming doesn't work.

Great thanks, sorry I was assuming this meant high krausen.

This actually depends on a few things. I’ve seen 8 point changes personally with hopcreep with a large dh load and warmer temps in 4 days, so (1.018-1.010) it’s certainly possible. 4 points is more typical though.

That said I do agree that the op should warm back up to 70-72 and rouse the yeast if possible.

Yeah I have been doing fairly hop heavy beers, not ridiculous mind like 13-18g/l, and I've not double dry hopped recently as I've been trying to resolve my oxidation issues, so only dry hopping once at high krausen and the brew before this one I even added my dry hops with the wort to avoid opening the fermenter at all, but I didn't do a diacetyl test on that brew so can't say for sure if it wasn't oxygen pickup when I transferred to my keg or not.

Ps this is my recipe if there is anything else you can see I'm doing wrong. Despite being a fresh faced brewer, I tend to write my own recipes, taking inspiration from other recipes so I could be doing something totally wrong that I haven't realised.

https://share.brewfather.app/GfEr8DUjQca3FY
I've heard of people packaging with ascorbic acid and/or potassium metasulphate but I didn't really know how you would add that without either opening the fermenter or your keg after purging it.

 

[Dgallo]

Great thanks, sorry I was assuming this meant high krausen.



Yeah I have been doing fairly hop heavy beers, not ridiculous mind like 13-18g/l, and I've not double dry hopped recently as I've been trying to resolve my oxidation issues, so only dry hopping once at high krausen and the brew before this one I even added my dry hops with the wort to avoid opening the fermenter at all, but I didn't do a diacetyl test on that brew so can't say for sure if it wasn't oxygen pickup when I transferred to my keg or not.

Ps this is my recipe if there is anything else you can see I'm doing wrong. Despite being a fresh faced brewer, I tend to write my own recipes, taking inspiration from other recipes so I could be doing something totally wrong that I haven't realised.

https://share.brewfather.app/GfEr8DUjQca3FY
I've heard of people packaging with ascorbic acid and/or potassium metasulphate but I didn't really know how you would add that without either opening the fermenter or your keg after purging it.

I did just review your process again and you say you are dumping the yeast...on what day are you doing this? And was the yeast dumped prior to hitting a stable gravity and completing your d-rest?

 

[mcinnes01]

I dumped some yeast after cold crash whilst getting ready to keg, but decided to do a diacetyl test before I kegged. I'd had stable gravity for a number of days before cold crashing.

 

[Dgallo]

I dumped some yeast after cold crash whilst getting ready to keg, but decided to do a diacetyl test before I kegged. I'd had stable gravity for a number of days before cold crashing.

Then nothing I see is glaring. If you’re dryhoping during active fermentation hop creep wouldn’t actually cause the diacetyl because it’s active. For your d - rest bring it to 22-22.5 c right at the tail end of fermentation and hold it ther for a minimum of 3 days. That will ensure clean up

 

[mcinnes01]

Great thanks I will definitely incorporate that in my next brew regarding the d-rest temps/time.

It does make me wonder where I'm getting diacetyl from if it's not hop creep , maybe I'm just not resting it long enough before I crash although you can see on my graph up top I did leave it a few days before I crashed.

 

[Dgallo]

Great thanks I will definitely incorporate that in my next brew regarding the d-rest temps/time.

It does make me wonder where I'm getting diacetyl from if it's not hop creep , maybe I'm just not resting it long enough before I crash although you can see on my graph up top I did leave it a few days before I crashed.

All beers produce some level of diacetyl during primary fermentation but it should/will clean itself up. In your case it didn’t. So moving forward finish your beer warmer around 22*c/72*f at the tail end of fermentation and then 72 hours after hitting fg. As a rule of thumb, you shouldn’t cold crash until about 10 days in primary

 

[mcinnes01]

Awesome thanks, I've been trying to do these fast turn around NEIPA processes. Ferment fast, minimum dry hop exposure, then package. But just doesn't seem possible to pull your dry hops out without potentially introducing oxygen. Like I said I am dry hopping in sealed hop filters but I would still need to open the fermenter to fish them out.

 

[Dgallo]

Awesome thanks, I've been trying to do these fast turn around NEIPA processes. Ferment fast, minimum dry hop exposure, then package. But just doesn't seem possible to pull your dry hops out without potentially introducing oxygen. Like I said I am dry hopping in sealed hop filters but I would still need to open the fermenter to fish them out.

Why not just leave them in and then take the canister out after transferring. I dryhop loose so my hops never come out

 

[mcinnes01]

Yeah I guess I could transfer to kegs for my secondary leaving the hops behind, do my d rest in the kegs and then cold crash, before transferring to another keg and carbing. Or get a brite tank

 

[Dgallo]

Also check out this thread.
https://www.homebrewtalk.com/threads/northeast-style-ipa.568046/page-349#post-9064550
If I recall correctly @TBryerton has the same fv as you and dryhops loose. He might be able to advise you better per your system

 

[mcinnes01]

Brilliant thanks for your help

 

[Dgallo]

Yeah I guess I could transfer to kegs for my secondary leaving the hops behind, do my d rest in the kegs and then cold crash, before transferring to another keg and carbing. Or get a brite tank

Why do you have to secondary. Just ferment and dryhop, perform a d-rest, and then transfer to your serving kegs. Unless you are dryhoping after fermentation and at colder temperatures, hopcreep will occur regardless if it’s in primary or secondary and using a secondary only increases your risk of oxidation

 

[mcinnes01]

I've not tried a secondary yet for that reason, but other than late hopping it seems the only way to leave your hops behind if you want to minimise contact time? Both seem like opportunities for oxygen pickup. Sadly my fv isn't a unitank so I can't get a spunding on it and there is no hop drop kit either.

 

[TBryerton]

Also check out this thread.
https://www.homebrewtalk.com/threads/northeast-style-ipa.568046/page-349#post-9064550
If I recall correctly @TBryerton has the same fv as you and dryhops loose. He might be able to advise you better per your system

I have a 7g ss brewtech and a spike cf10. I like the spike better for dry hopping just because it has the extra tc port, but honestly, haven’t seen any difference in the results between the two. For the SSB, after I pull yeast (under pressure) I’ll remove pressure, pop the top port and push co2 in as quickly as possible - just leaving the open co2 tube hanging in the opening, toss the hops in, remove the co2 hose, close and purge. I usually recirculate from the bottom with co2 since I’ve been adding hops a little cooler. The best thing I’ve done since I started brewing is building a glycol chiller. I was having a hell of a time transferring. Now I have no problems and get much cleaner beer into the keg. Also, I’m not a believer in rushing, even for this style, at any point in the process. Hope this helps...

 

[mcinnes01]

I have a 7g ss brewtech and a spike cf10. I like the spike better for dry hopping just because it has the extra tc port, but honestly, haven’t seen any difference in the results between the two. For the SSB, after I pull yeast (under pressure) I’ll remove pressure, pop the top port and push co2 in as quickly as possible - just leaving the open co2 tube hanging in the opening, toss the hops in, remove the co2 hose, close and purge. I usually recirculate from the bottom with co2 since I’ve been adding hops a little cooler. The best thing I’ve done since I started brewing is building a glycol chiller. I was having a hell of a time transferring. Now I have no problems and get much cleaner beer into the keg. Also, I’m not a believer in rushing, even for this style, at any point in the process. Hope this helps...

That's really helpful thanks. I've just built a glycol chiller out of an old MF ale chiller and I've rewired it to control using brewpiless and fermentrack. Not quite finished yet hence my early control issues where the temperature shot up to 26c and I've not wired in the heat wire that is wrapped around the cone but hopefully I should have a lot more control on the next one.

Are you using the domed lid on the SSB? And you just add your hops and co2 line through that port? I've drilled my chiller coil in to the side of the fermenter so I can use the domed lid and ferment with a little pressure.

 

[TBryerton]

That's really helpful thanks. I've just built a glycol chiller out of an old MF ale chiller and I've rewired it to control using brewpiless and fermentrack. Not quite finished yet hence my early control issues where the temperature shot up to 26c and I've not wired in the heat wire that is wrapped around the cone but hopefully I should have a lot more control on the next one.


Are you using the domed lid on the SSB? And you just add your hops and co2 line through that port? I've drilled my chiller coil in to the side of the fermenter so I can use the domed lid and ferment with a little pressure.
View attachment 719361

Yes to the lid. Is there another option? I hate that there’s no flat surface on the lid. Otherwise I’d add a weld-less TC port. Your port looks much smaller. Mine is the BME. I never realized the tops were different. I add everything right through there. I need to find a way to hook up co2 someplace else just for piece of mind. I suppose I could just do it through the bottom.

 

[mcinnes01]

Yeah I've got a flat top too with an extra TC port, but it can't take pressure the same as the domed lid. It used to have the chiller coil suspended from the flat lid, but I've drilled and mounted it through the side of the fermenter now so I can use this domed lid. The BME version has a 3" port I think doesn't it. I've stuck a sight glass at the bottom and was considering a T with a carb stone so I can oxygenate my wort when I put it in and then blast co2 through it when dry hop or if I need to put anything in the top.