Hi, All this time I've only been boiling ~3 gallons and then add water to the fermenter to make it 5 gallons. (cause I don't have a large enough stock pot). Is there any dramatic differences in outcome doing a full boil? I've never done one, so I can't tell the difference. I just wanna see if it's worthwhile to buy a larger pot. Many thanks.
There are two aspects that are commonly discussed between a partial boil and a full boil: · Hop Utilization · Wort Darkening The conventional wisdom is that a partial boil has lower hop utilization but there was a study conducted by BYO magazine and Basic Brewing Radio (BBR) on an Imperial IPA which did not show any difference in hop utilization between a partial boil and a full boil. You can listen here (March 4. 2010): http://www.basicbrewing.com/index.php?page=basic-brewing-brew-your-own-experiments A partial boil will result in darker wort. If achieving the lightest colored beer (e.g., a very light colored Blonde Ale) then a full boil will be beneficial. Cheers!
Based on that study and your own experience, do you think it's possible to get, say, 80 IBUs in a partial (say half) boil batch?
I listened to that study, and basically the results they get from all the testers are pretty inconsistent. Some got better results in one and others the other way round. However, they all came to one conclusion: The difference in the 3 methods, regardless of nose, color, and hop, are little to none, pretty neglegible. That's what I gather from listening to that podcast. So I'll continue with my partial boil strategy. Don't wanna waste $$ on a larger pot.
If you want to experiment yourself just do a half batch that way you can do a full boil. See if you notice a difference if you brew the same beer as a full boil vs. partial boil. I suspect that there is not a huge difference unless you are trying to do a highly hopped or lightly colored beer.
Use two pots and split the hops proportionately between the pots. This lets you get a full boil on say a glass stovetop (which, btw, sucks for brewing). I used to do it and it worked like a champ. If you only have one wort chiller (like most of us) then chill one, then the other. You could stagger the boil times to account for this if you wanted to be really anal about it. I did a couple batches with top-off before I started splitting the boil. Although my first batches were plenty good enough, I am certain that the full boil results in better beer. As was stated above, don't do anything half-assed.
Or, if one of the two pots is big enough to handle the full *post*-boil volume (plus chiller), pour them together and chill all at once.
In my eyes, it's only a problem if you're trying to max out ibus. What you're ultimately doing is watering down the beer by doing a partial boil. That's fine when the only thing your truly watering down is sugars since you can get way more sugar into solution than a brewer needs. Iso alpha acids are another story though, the saturation ceiling is fairly low, so say you are able to get 100ibus from the partial boil...watering it down with 2 gallons, you're now down to 60ibus. Fermentation will probably drag out another 10-20% from solution so with partial boils you're looking at a max ibu rating of ballpark 50ibus whereas with full boils you maybe in the 80ibu range.
If you like the beer you're getting from a partial boil, why worry about it? Don't fix what isn't broken. I've been doing full boils since I started doing all-grain a few years ago. My beers have definitely been better, but that may be simply due the fact that I'm doing all-grain. Or maybe my process/technique has improved. Or maybe because I'm doing full boils. Or maybe all of the above. Or maybe none of the above. (who cares?) FWIW, I did a partial boil IPA this January and I liked it just fine. What conclusions can I draw from that? Only that I should keep brewing! IMNSHO, everybody is over thinking this.
I don't have much to add, other than an anecdote. Last time I made a Hefeweizen, I overshot my gravity by enough that I wanted to dilute it with water prior to fermentation. I feel this had an adverse effect on the flavor, even though I used distilled water. I'm not sure if this is due to dilution affecting mineral concentrations, or was just in my head, but I would highly recommend that, if you are going to continue to go the dilution route, you treat the diluting water to a mineral content similar to that you brew with, to ensure the beer turns out right. Seems to me this would be a necessary step in ensuring the best possible end product.
Minerals don't evaporate. The stuff that boils away is, for all intent and purpose, distilled water (indeed, that's how distilled water is made). Adding distilled water post boil compensates for excess boil off - nothing more.
I realize that minerals don't evaporate, but it takes significantly less water to make a 3 gallon batch than a 5 gallon batch. So the final mineral composition of a batch made with tap water to produce 3 gallons of wort, which is then diluted pre-fermentation with distilled water (which is the way all the brewing books say to do it for beginners) will have lower mineral concentration than the straight tap water. Unless you take the time to make a 5 gallon batch and boil off 40% of it, but I'm not sure why you'd want to do that when treating the water is a lot faster.
I don't know what you mean by don't matter very much, but I'd say Mg, Na, Cl, and SO4 ions all affect flavor.
When you said you overshot your gravity, I assumed that meant you had more loss to evaporation than you expected, in which case, distilled water would be ideal to compensate. Adding the 'missing' water due to a partial boil should already be factored into the recipe. It shouldn't water it down. Regarding the impact to flavor using distilled over tap water, I'll leave that to the experts.
