I've had some time off, so I took the opportunity for some more home brewing. I thought I'd share some photos from the most recent endeavour, along with some comments on the process.
I recently purchased some gear for brewing: a 42 quart stock pot and a propane burner. Hitherto I've been brewing on the stove in a 21 quart pot, which had three limitations:
- I couldn't boil more than about five gallons in the 21 quart pot
- our poor stove couldn't really push 21 quarts to a full boil
- our stove, being electric, doesn't really give the instant heat needed for timely temperature adjustments
By moving to a 42 quart pot, we've increased our maximum boil volume to between seven and eight gallons; by moving to a propane burner, we've solved the sufficient power and "instant heat" problems.
In general terms, brewing involves taking some combination of grain, water, yeast, and hops and creating beer. The lifecycle of beer creation more-or-less follows the grain:
- grain must be malted, which means it's germinated, then the germinated grain is cooked to form malt
- malt is milled in a grain mill to produce grist, which is crushed grains (not flour)
- grist must be mashed so that the starches in the grist are converted to fermentable (and non-fermentable) sugars, producing sweet liquor
- sweet liquor is boiled with hops, seasonings (spices, etc.), and adjuncts (non-malt fermentables like molasses, honey, or turbinado) to form wort
- wort is fermented with yeast(s) to form beer
So we malt the grain, mill the malt, mash the grist, boil the sweet liquor, and ferment the wort.
Most brewers don't malt grains on their own. Almost every home brew store will carry a significant selection of malted grains, which are ready to be mashed. Some home brewers prefer not to mash the grains themselves, purchasing malt extract, which is essentially concentrated sweet liquor. Some go a step further, purchasing hopped malt extract, which is basically concentrated wort. I personally do what is called "all grain brewing": I buy malted grains, mill them in the store, and mash them at home to create the sweet liquor for my beer. My local home brew store carries an impressive selection of malts and offers free milling for malts purchased there.
There is a terrible divide in the brewing community (especially online) between those who brew with extracts and those who brew "all grain". It is true that "all grain" brewing requires more time and equipment, but it's also true that brewing with grains allows a great deal more fine-tuning of flavours than extracts. My decision to brew "all grain" is based on two factors:
- where I live, it's significantly cheaper to buy malted grains than to buy extract
- I think it's more fun to mash grains than to use extract.
Not everyone agrees with me, which is OK. I've had some excellent extract and partial-extract (i.e. mashing
some grain and boiling with extract) beers. I've also had excellent all-grain beers. If you're having fun and you're liking the beer you make, you're doing it right.
Mashing grains is essentially the process of kicking the enzymes in the grains into action so that they digest the starches in the grains and produce sugars. Some of the sugars are fermentable, some are not. It's possible to control this process in order to produce the desire combination of fermentable and non-fermentable sugars by controlling the mash temperature. Mashing is typically done between 145 and 170 degrees Fahrenheit. In general terms, lower mash temperatures produce more fermentable sugars. So a Pilsener, which is very dry, is mashed much cooler than a fruity ale. There are other factors, but mash temperature is a great driver of the sweetness or dryness of the finished beer.
Mashing requires a vessel in which to mash, a mash tun. This is essentially a vessel large enough to hold the grist to be mashed, plus sufficient water (typically one-and-a-half quarts of water per pound of grist) for the mashing. The tun holds the mash (water + grist) at a more-or-less constant temperature for the mash schedule (usually an hour). After mashing, the mash is lautered, which means the grist is separated from the sweet liquor. Part of lautering is sparging, or rinsing the grains with fresh water to ensure all the sugars end up in the liquor, rather than stuck to the discarded grains.
A few years ago, some Australians started a new technique, "brew in a bag." This is really cool: rather than having a dedicated mash/lauter tun, you put a strainer bag right into your brew kettle, mash in the kettle, and then lauter (strain) your sweet liquor by lifting the bag out of the kettle. This saves both time and money (you don't have to buy a separate tun), but it arguably makes less clear beer.
I still don't have a mash tun, so I work more-or-less with the BIAB concept. That kind of backfired on me the last brew day, so I ended up modifying it a bit... Ames and I sewed up a pretty cool grain bag for BIAB last month. I wanted to use it with my new pot, but it just wasn't big enough. I tried putting the bag inside the steamer basket that came with the pot, but it didn't sit low enough for the grist to get a good soak.
Then I tried putting it directly into the pot, but it just wasn't big enough.
I finally gave in and mashed the grist plus four gallons of water in my older 21 quart pot
That was the maximum capacity of that pot.
We mixed the grist into the water to form a really thick porridge and let it sit at 133 Fahrenheit for 20 minutes. After 20 minutes, we raised the temperature to 156 Fahrenheit (constantly stirring so as not to scorch the grist), and let it sit for another 90 minutes. After 90 minutes we raised the temperature to 167 Fahrenheit (again stirring constantly) and let it sit another 15 minutes.
For the sparge, we heated another four gallons of water to 170 Fahrenheit in the larger pot. After the final 15-minute stage of the mash (the "mash out"), we pulled the grain bag out of the smaller pot and immersed it in the fresh four gallons. We stirred it around and let it set for a while to ensure all the sweet liquor was rinsed from the grains, then pulled the bag out of the larger pot, laid a grate across the pot, and let is rest on the grate to drain. After several minutes, when the bag was almost completely drained, we put it into a basin to finish draining and began the boil. The bag drained for a little while longer into the basin, and after several minutes we poured another cup or so into the boil kettle.
The boil is the simplest part of the process. The only really thing to watch for is the boil-over, which is only really a danger in the first few minutes.
Foam does form on the surface, when it breaks up and the liquid is visible again, it's time to put in hops.
The hop additions define the timeline. Hops vary in flavour, colour, and "alpha acid" content. Alpha acid is what makes hops bitter, but it needs to be converted by boiling. As hops boil, they lose their aroma and flavour, and become more bitter. So hops added earlier in the boil contribute more bitterness; hops added later add more flavour and aroma. I generally boil for an hour: the first hop addition is the bittering hops, which boil for the full hour.
We made a stout this time, I saved the recipe on hopville.com. I wrote the recipe, but I did a lot of looking at other recipes to figure it out. So... it's more or less my recipe, but I did certainly refer to many others. This recipe calls for two hop additions: one ounce of Northern Brewer hops at 60 minutes, one ounce of Goldings at 30 minutes.
So we added our Northern Brewer hops and set the timer for an hour.
Hops need to be stirred in, they float pretty outrageously.
After the boil is done, there is a flurry of activity. You need to chill the wort as quickly as possible, get it into a fermenter, and get yeast into it. The yeast doesn't like temperatures over 90 Fahrenheit, and prefers to be in the mid-seventies. But cooling five gallons of boiling hot sugar water is difficult. I use a friend's wort chiller, essentially a copper coil that runs cold water through the wort.
This is where you need to play the sanitation game. Wort is the perfect environment for nasties to grow. It's pretty hard to make something dangerous to drink: the alcohol in beer is a decent preservative. But it's possible to get infections in your beer that make it undrinkably nasty. So you use sanitizer. I use iodophor, but there are others. Essentially you need to sanitize anything that touches your wort after the boil: the fermenter, any thermometers, hydrometers, tubing, filters, strainers, or spoons. It's not as annoying as it sounds, but it does require going slowly and carefully.
So in our last batch, we used a strainer bag to filter the hops, then filled a plastic fermenter with our wort. Once the wort was cooled, we put a package of dry yeast into the wort, covered the fermenter, and put an airlock on it.
It's now beer: it's been fermenting a couple days now. A lot of home brewers use two fermenters with their beer. They'll let the beer go for a week or two in a plastic fermenter, then siphon it into a glass carboy and let it ferment another week or so. I've personally been satisfied to just leave my beer in one vessel for four weeks or so, then bottle it directly. People fight a lot about this online: I've done it both ways and I prefer the simpler approach of leaving it in a single vessel for longer.
When I go to bottle it, I'll boil a little sugar in some water, add it to the beer, and siphon it into bottles. The added sugar kicks off fermentation in the bottle, which will carbonate it in the bottle. It'll take another three weeks (or so) for it to carbonate. So... it should take a total of seven weeks to make a finished product.
Not all batches are ready to drink on schedule. Higher alcohol beers take longer to mature and really become drinkable; beers with harsh flavours can also do well with some extra time. I'm not completely sure at this point which ones take longer and which ones will be ready when they're young. I'm hoping this batch is ready for the Christmas break, but I might be disappointed. I've got plenty of bottles from earlier batches, so it's not like I'll be desperate for beer; but I think a nice stout will be pleasant for wet and rainy days. I suppose I should actually post a review when I can taste it.
So that's an overview of home brewing. I've been enjoying making my own brew. In fact, I've been making a lot more than I've been drinking. I suppose that's not a bad thing. I've been hoarding the home-brewed for the holidays, and I'm expecting I'll have to do some serious brew sessions early next year to replenish the stock. We'll see.
UPDATE 2011-11-06
I brewed this beer on Thursday. Today's Sunday, and the activity on the fermentation lock's dropped off. That doesn't mean a whole lot, but it's a hint that the bulk of the fermentation's complete. My experience with this particular yeast (Nottingham Ale Yeast by Danstar) is that it ferments pretty aggressively and finishes quickly.
Today the fermenter looks like this:
I used a plastic fermenter for this, so you can't see a lot in detail, but the silhouette of the contents is significant. The top layer, that looks sort of foamy, is the result of
krausen. Krausen is a layer of foam that's generated by vigourous fermentation, early in the fermentation process. Krausen dissipates, but it leaves this residue, which is a bitter and foul-tasting scum. This is a good sign. Below the krausen ring is the actual beer. Under the beer is
trub, which is the leftovers from fermentation. The trub contains proteins from the grains and hops, spent yeast, and various other fermentation by-products. When it comes time to bottle the beer, we'll siphon it off the trub so that only the middle layer makes it into the bottles.
Yeast flocculates--- or settles to the bottom--- when it's done. I typically "wash" the yeast, rinsing it from the rest of they trub and beer so that I can use it again. I generally get three batches of beer from a yeast purchase. There's still a great deal of yeast in suspension, even after a month. That's the yeast that will carbonate the beer in the bottle.
Although we technically have beer at this stage, it's incredibly young and "green". This beer needs to age at least another couple weeks before bottling. In my experience, you can bottle just fine after only two weeks in the fermenter, but the beer will require more time in the bottle to condition. I've decided it's easier to leave it a full month in the fermenter, as it doesn't make it drinkable any faster to bottle it sooner. Even though the majority of the fermentation is done, there is a lot more "cleaning up" the yeast will do to produce a cleaner, clearer beer. This is a stout, so we're not really looking for "clear" as in "see through", but the more stuff settles out, the better it's going to taste.
