This is my first brew after I came home from deployment and 8 odd months of research reading and monitoring the forums so let me start by saying I'm not worried. Just questions. The kit was a 5 gallon English brown ale. I ended up only using 4 gallons of water not accounting for boil off and I added a dry yeast of Nottingham ale yeast. Fermentaction is steady. So the question is what should I expect? Aside from higher abv and ibus. Will the yeast crap out? How much longer should I leave it in the fermentor? Would the experienced home brewer still anticipate a descent beer?
So, your IBUs will actually likely be lower than anticipated. Hop utilization in the boil decreases with increasing gravity, so your higher than anticipated OG will not allow as many alpha acids to isomerize. That being said, it should turn out fine. Just make sure you're fermenting in the mid to low 60s from here on out to avoid off flavors. As for fermentation time, it probably will ferment just as fast, but you can only know it's done for sure with specific gravity readings. If the density result is the same for a couple of days and around where you are expecting it to be, the yeast is pretty much done. At that point, you're going to want to let it sit for about a week on the yeast so those little guys can clean up some undesirable byproducts that could still be in your beer.
An English brown probably clocks in at 1.040-1.050, 20-35 ibus. If your beer is 20% more concentrated, 1.048-1.063, 26-44 ibus according to my early morning arithmetic (not accounting for any loss of hop utilization efficiency, which may or may not occur). One packet of healthy Nottingham should have no problems fermenting 4 gallons of this. If you properly rehydrated your yeast, pat yourself on the back. If you didn't rehydrate, and my gravity estimates are accurate, I expect the yeast are still up to the job, but you may have killed some cells and consequently underpitched a bit - you wouldn't be the first homebrewer to do this, and most who have done this shrug their shoulders and swear that they made good beer. Nothing to worry about.
If you mean IBUs will be "lower than the OP might think by simply adjusting for same Alpha Acids in less volume," that's true. But the IBUs are going to be higher than they would have been in 5 gallons. Just not quite inversely proportionally higher. I think that's what you were saying, but I didn't want OP to think his IBUs will be lower than the original recipe expected.
Thanks for the comments guys the fermentation did take off the first 2-3 days and since has slowed but there is still some airlock activity however the KruSen on top has disabated. As for temperature, my house stays around 68 during the day and 65 or so at night so I hope that's adequate. Thanks again.
You likely will lose additional liquid to the trub when you package your beer, so if you want to get more beer for your work effort, there is nothing wrong with adding some top-off water at the time of bottling/kegging. (Stay away from using chlorinated water.) I have never personally added a gallon at this stage, and I don't see a reason that you can't, but that can be up to you depending on how satisfied you are with having a beer with an ABV that is higher than you wanted. My caution for adding water is to mix it in well (with gentle stirring only) along with your priming sugar if you are bottling so that your beer is consistent from bottle to bottle.
Just to let everyone know I bottied today after 3 weeks I tasted some alcohol was a little present not in your face or anything still nutty and roasty thought it was still smooth nice level of bitterness. It came out to 10 bombers a and 10 12oz which is about what I was expecting aND waneed so thanks guys. The extra week was a good tip.
