Second brew ever...I just bottled an IPA with an OG of 1.07 and FG of 1.028, all grain wiht US-05. It was in the primary for four weeks at around 63-64F ambient temperature, with two days of cold crashing at the end. Unfortunately, because I didn't have a good beer/wine thief, I couldn't take gravity readings until I was racking to my bottling bucket. Because I fermented for 4 weeks, I am/was thinking that whatever the FG that is what it will be. I realize it is a very high FG for an IPA, but it likely has to do with the fact that I had my strike water at around 190F instead of 165F (I know, really stupid, but I did it because I thought the cold weather would rapidly drop the temperature). After realizing the mash temperature was not dropping very quickly, I did what I could to drop down the temperature to 165F over the first 10-15 minutes of mashing. I suspect the high temperature killed some of the fermentable sugars and is causing the high FG, in which case my understanding was that there is nothing that could have been done. Now I am wondering: 1. Was I right to bottle now, or should I have waited longer or pitched more yeast? 2. If there is more attenuation to be done, what are the chances of bottle bombs? 3. Will this taste insanely and undrinkably sweet?
The high temp most likely caused much of your enzymes (amylase) to be denatured, i.e. deactivated. Worse (in your case) is beta amylase denatures at a relatively low temp (160), this is the enzyme that helps produce the most fermentable sugars. Alpha amylase denatures higher (168+) which is responsible for producing longer chain sugars which are less fermentable. From your description, it sure sounds like you whacked your "betas" and most of what's left is a result of alpha amylase activity. IMO there is little you can do at this point. If US05 didn't attenuation it before it's unlikely to go back to work. I say unlikely because it sounds like you never raised the temp in your primary. Next time consider letting it rise to 70'ish at the later stages to give the yeast every opportunity. As for taste: you'll have considerable residual sweetness but it's an IPA so your bitterness will be high . . . may resemble a weak barleywine but who really knows? Here's a good read on how all the temps effect the mash: https://byo.com/mead/item/1497-the-science-of-step-mashing (see sections on Enzymes and Starch Conversion) Here's a good read on what happens in the primary: https://www.morebeer.com/articles/conditioning As for lessons learned, you see the necessity of good temp measurements. Just being off a degree or two in the mash can give unexpected results. Here's some software that will help predict mash parameters (and you realize the need for an accurate thermo): http://www.brewersfriend.com/mash/
Good equipment and stuff is definitely important. But to be honest, the high temperature was me just being inexperienced and plain stupid in the moment. So would you say the chance of bottle bombs are low? That's what I am most concerned about right now. I'm thinking I need to store the bottles in a safer location (like a plastic box), and test the carbonation in a bottle after a week or so.
Hey, the president of my brew club just brewed a Rye IPA . . . and forgot to add rye . . . it happens. Bottle bomb percentage is low but I would take precautions as if anything could happen. If the bottles are warm they could carb up in a couple of days. It's easy to monitor; slowly tip the bottles upside down and look for sediment to drop from the bottom (which is now on top). The more sediment, the more the yeast has grown, the more CO2. It never hurts to do a test around day 5 to 7, then go from there. You could even de-gas a beer and measure FG again. If you notice things are getting out of hand it's not too difficult to pop 'em all and re-cap. The old-timey brewers could make world class beer by seat-of-their-pants brewing. I favor using software to help shape the final results. Lots of good brewing software out there, much of it free.
Were these gravities measured with a hydrometer or a refractometer? If you used a refractometer, you must apply a correction factor or your FG reading will be misleadingly high. [edited for clarity]
@PortLargo Won't the FG reading be inaccurate given it's been mixed with the priming sugar and carbonated? Or does de-gassing it make it accurate again? @minderbender I used a hydrometer.
I am going to be a party-pooper and say that if I had brewed this beer, I would (very carefully) open all the bottles and dump them. My reasoning is: 1. You might have bottle bombs. That's dangerous. You can take steps to minimize the danger, but the consequences can be severe enough that I personally wouldn't risk it. 2. The beer is probably not going to be great. I don't want to shit on your beer, but it sounds as though it's not what you were trying to brew (and not in a good way). If the chances of bottle bombs were low enough (not necessarily zero), or if the beer were good enough, I might go the other way. But in this situation, I would dump the beer and plan ahead to a better brew day next time. If you decide to keep the beer, I would wear goggles when handling the bottles. I know that sounds extreme, but goggles are cheap and eyes are important.
Your priming sugar should ferment 100%, leaving the residual sugars in the beer exactly where they were before you started carb'ing. If you see the FG dropping that means the yeasties are dining on something besides the simple sugars. I've had my share of over-carb'ed beer bottles and it ain't really a disaster. Keep a handle on it; start checking in about 5 days, maybe open a bottle on day 7 and see how it's going. Lots of variables here but the process is manageable. If you see the pressure starting to get out of hand just chill (the beer), then pop the caps and let 'em off-gas for a couple of minutes, then re-cap and start monitoring all over again. Caps are 'bout 3ยข . . .
@PortLargo, I defer to your experience (I've never tried your method, and the one time I had bottle bombs, I immediately dumped the entire batch), but how much CO2 can you really eliminate through this procedure? If the beer "finished" at 1.028, then it could have many volumes of extra CO2 waiting to be produced (we just don't know). Each recapping might vent a fraction of a volume at most, right? (While replenishing the oxygen in the head space.) And how will @ic_1993 know when it is safe to stop? I'm trying not to be unduly pessimistic about this, but it seems like a lot of effort and risk for what is unlikely to be a stellar beer.
Let the taste help you decide what to do with this beer. Since you didn't taste it at the time of bottling, and since there is an opinion above that the beer will not be very good, open a bottle now and taste it. It's likely still going to be flat, but you should get a good idea whether it's overly sweet, or if it just isn't a good beer. After tasting it, decide from there whether you dump it or begin to take precautions against over-carbonated bottles.
Thanks everyone. @Mothergoose03, I did taste it at bottling and it didn't taste bad (it didn't even taste overly sweet either to be honest). But I can't really say much as this is only my second homebrew ever. I understand the potential danger of bottle bombs, but I would really like to be able to see how it tastes fully carbonated before deciding to dump it (unless it is clearly going to be a massive disaster). Given that my strike temperature was way too high, a high FG is expected. Why would this, along with a decently long primary time, not be enough to (mostly) conclude that the fermentable sugars were indeed consumed by the yeast?
I don't think you need to have any worry about bottle bombs for the first 10 days, so you can use that timing to taste one that is carbonated (assuming it does have some good carbonation by then). Did you take two gravity readings to help validate that fermentation did completely stop? I have a feeling that you'll have a drinkable beer, but it's not likely going to taste like what you may have been expecting.
This just seems like a very low degree of attenuation for US-05, which is normally highly attenuative. You're right that there are other factors that point toward a complete fermentation, in which case the high final gravity might be explained by the very hot mash. What worries me is the situation that would be created if the US-05 continued fermenting the beer down to a more normal FG... that would create extremely (and dangerously) over-carbonated bottles of beer. Certainly you have the option of seeing how it tastes in a week or 10 days, and then going from there, as suggested above. I just urge you to be safe. I have this image in my head of someone holding up a bottle to look at it against the light, and then BOOM. It makes me shudder. Please be safe. [edited for clarity]
I only had a couple of bottle bombs and frankly they never were a big deal, usually the bottom of the bottle coming off. No real explosion and never when I was around. Then again I never really had many beers that I bottled before they were ready. If fermentation was done and your FG was high as you said likely due to the high strike temp. The one batch I overcarbed I just put in the fridge to stop fermentation and not a single one popped after that.
I ended up tossing it all out. It tasted way too sweet to bother to keep. After two weeks, there were clear signs of overcarbonation. To the next batch now.
I did this same thing with my first batch of all grain. I added powdered amylase to the carboy and it fermented to a lower gravity. I will write a post about it later. I am waiting to try the finished beer before I do a write up on it. I bottle carbed 11 days ago so hopefully I'll have something soon .
