For those following this blog, you know that I brewed my first batch of beer a couple months ago. The process was lots of fun, and it was very interesting to see how everything works together to produce beer.
So how did it come out? Bitter. Too bitter. I actually don't particularly like it. (Luckily, my father in law loves it, which is encouraging.) But why is it bitter?
The Water
Initially, I blamed the water. I was using unfiltered tap water, and I know that our tap water is heavy in iron. Plus, from everything I'd read, tap water may have residual chlorine in it that can lead to off flavors and hurt the yeast.
But no, that can't be it... The water, despite being iron-rich, still tastes fine. And, the thing that nobody mentions about chlorinated water is that boiling it drives off the chlorine. The only time that residual chlorine matters is if you only do a partial boil and top off with tap water. (Which you should never do, since tap water may have microbes in it that can infect your beer; you should boil your top-off water or use bottled water.)
DMS (Dimethyl Sulfides)
Well, maybe it was DMS. DMS is produced by boiling the wort (raw beer, before adding the yeast), and is carried away by steam when you've got a good rolling boil. I didn't have a good rolling boil, so maybe there was some DMS still in solution.
But no, that couldn't be it either. DMS produces a flavor more like cooked vegetables, not bitterness.
Hot Sparge
Sparge water! It must have been the sparge water! You shouldn't sparge your grains (rinse them to extract more flavor) with water above 170*F. I used 170* sparge water, perhaps my thermometer is off a bit and it was even hotter! That could rinse tannins into the wort!
Hmm... no, that couldn't be it... Tannins lend astringency and dryness, but not this bitterness I was getting. Besides, a couple of degrees wouldn't have killed the whole batch.
Frustration
So what could it be? I was pretty frustrated at this point; what other mistake could I have made?
Now for a side-track to see how I figured it out. Two weeks ago, I was brewing another beer (this time a Brown Ale using the Cumbrian Double Brown Ale kit from Northern Brewer). While reading over the instructions, I noticed a bit describing the changes to the recipe that you should make if you are doing a full boil. (A full boil means that you are boiling the entire volume of wort that you are going to ferment, as opposed to a partial boil, where you only boil a portion of highly-concentrated wort and water it down to achieve the proper volume just before adding the yeast.)
Hops!
One of these changes was to reduce your bittering hops by 25-30%. Bitterness is more efficiently extracted from hops in a larger volume of water!
The Scotch Ale that I made was also a partial boil recipe where I had done a full boil... So I should have used 25% less bittering hops.
But wait... Isn't there something else that affects hop extraction? Oh yes! Late extract addition also increases bittering efficiency! (Late extract addition means that the malt extract is added close to the end of the boil; it is generally thought to improve the beer by not caramelizing the malt extract from a long boil, and also by better utilizing the hops. The other, more common method, is early extract addition.) I used the late extract addition method, so I got more bitterness out of my hops than I really needed. So I should have reduced my bittering hops by another 25%!
So, why was my Scotch Ale so bitter? I used almost twice as many hops as I needed!
"But wait!" you cry out, "25% + 25% = 50%! That is half!" Ahh yes, young padawan, that is true. However, I would have wanted to reduce my initial hop addition by 25%, and then reduce the remainder by 25%. So, with 1oz Chinook hops, that's 1oz * 75% = .75oz after adjusting for boil volume, and then .75oz * 75% = .5625oz, or just slightly more than half of what the recipe called for.
Oh, and there's one more source of bitterness: yeast. If you don't let your bottle-conditioned homebrew sit upright in the fridge for at least 48 hours, there are is so much yeast in solution that it will take on a bitter, moldy character which is really not very good. The last one I drank sat in the fridge for four days, and was quite good (except for the unnaturally high hop bitterness).
So, in the words of Charlie Papazian, "Relax. Don't worry. Have a homebrew." And don't overdo the hops.
