Thursday, September 20, 2012

Having your (yeast) cake, and brewing the beer too...

I made a comment to a facebook post earlier today about saving yeast from a smack pack. A previous commentator admonished the owner of said smack pack to wash the yeast for re-use once he had brewed the beer. I commented and said that there's no reason to wash the yeast, since you could just save a portion of the starter and re-cuture. I then got yelled at that you "don't save a piece of any starter, certainly not of lager." Seemed to me like a good chance to crunch some numbers.

So lets start with the basics. Why do we build a starter to begin with? Well, it's because we need a certain number of yeast cells to insure a healthy fermentation and, dang it, the yeast we get from the store just isn't enough. Let's take the case of my friend's brew as a test subject: He's planning to brew a fairly strong lager, so let's assume he's starting with an OG of 1.060. Using the handy-dandy Mr. Malty pitching rate calculator I find that I need no less than 439 Million yeast cells.

Now, given that the average yeast vial or smack pack is suppose to have about 100 Million cells in it, it would take four of them to pitch a proper pitch. But the fact is that yeast dies in transit, and over time the viability of that vial degrades. If I'm really lucky, and the vial was transported cold, and was very fresh when it was bought, and I pitched it right away, I might get about 40% viability. So of that theoretical 100 Million cells, I have about 40 Million to work with. Mr Malty doesn't tell me how big of a starter I'd need for that, but does: it would take a 12 liter starter to make enough yeast for this beer. For those following at home, we're talking about a 18.9 Liter brew.

The reason it takes so much starter wort to generate this much yeast is that growth is not liner to starter size. In other words, a 2 Liter starter will not propagate twice as many cells as a 1 Liter starter. It's the law of diminishing returns, on a cellular level.

So how do you make that much yeast? Well, you try to always pitch as much yeast as would hit the optimal growth rate for that size starter. In other words, the more starter wort you have, the more yeast you need to pitch. Or, flip it, the more yeast you have, the larger a starter you can pitch it to. This is called making a step-up starter. 

So lets take our 40 Million cells that we got in the smack pack, pitch them into a 1 liter starter, and throw it on a stir plate until it ferments out. At the end of fermentation, our yeast has grown to about 139 Million cells (according to yeastcalc). Now lets do it again, take those 139 Million, and pitch them into 2 Liters (more yeast means bigger starter, right?) let it ferment and we get 377 Million cells. Getting close to the target, but not quite there. So lets do it one more time, and pitch into a 3L starter. At the end of that cycle we get...ready for this?...a whooping 779 Million cells! WAAAAY more than we need. In matter of fact, if we took that 3 Liter starter, mixed it well, and pitched only 1.75 liters of it into the wort, we will hit our target rate almost exactly. And the rest? That's enough yeast slurry there to fill a couple of vials and share with friends, and we've made it using half of the starter it would have taken in a single-step starter.

So yes, you can save a portion of the starter and re-culture it. in fact, if you do your step-up right, you probably wont need to re-culture. You'll have enough ready to use yeast that you can pitch what you need and save the rest. So get starting!

Monday, September 10, 2012

Tasting Notes: ESB

The genesis of this beer was in a period of intense brewing leading up to this year's Longshot competition.  I had decided to enter pretty much at the last second, and was kind of scrambling for a third beer to enter (my friend Levi was supplying three beers, and with my three we were splitting Beer-d's six-for-the-price-of-five deal.) Eventually, I ended up not submitting it, favoring instead the Kosher (oyster) stout. As a result this has become somewhat of a neglected beer in my collection, and it wasn't until a couple of days ago that I decided to give it a proper tasting and write up notes. I kind of wish I hadn't waited so long, since Bitter should be drunk fresh, and after five months, this beer is beginning to loose its sparkle.

The Recipe:
Recipe: E.S.Bitching (ESB) TYPE: All Grain
Style: Extra Special/Strong Bitter (English Pale Ale)
---RECIPE SPECIFICATIONS-----------------------------------
SRM: 7.6 SRM  SRM RANGE: 6.0-18.0 SRM
IBU: 35.3 IBUs Tinseth IBU RANGE: 30.0-50.0 IBUs
OG: 1.057 SG  OG RANGE: 1.048-1.060 SG
FG: 1.015 SG  FG RANGE: 1.010-1.016 SG
BU:GU: 0.614  Calories: 535.8 kcal/l Est ABV: 5.6 %  
EE%: 72.00 % Batch: 20.00 l      Boil: 30.48 l BT: 90 Mins


Total Grain Weight: 5.08 kg Total Hops: 90.00 g oz.
---MASH/STEEP PROCESS------MASH PH:5.40 ------
Amt         Name                              Type    %/IBU         
4.75 kg     Pale Malt (Weyermann) (3.3 SRM)   Grain   93.5 %        
0.23 kg     Carahell (Weyermann) (13.0 SRM)   Grain   4.5 %         
0.10 kg     Caraaroma (130.0 SRM)             Grain   2.0 %         

Name     Description                   Step Temperat Step Time     
Mash In  Add 14.19l water at 74.7 C    67.0 C        60 min        

Batch sparge: 3 steps (1.37l, 10.48l, 10.48l) of 75.6 C water

---BOIL PROCESS-----------------------------
Est Pre_Boil Gravity: 1.046 SG Est OG: 1.057 SG
Amt         Name                                Type    %/IBU         
60.00 g     Goldings, E.K. [5.50 %] - Boil 60.0 Hop     35.3 IBUs     
0.50 Items  Irish Moss (Boil 15.0 mins)         Fining  -             
30.00 g     Goldings, E.K. [5.50 %] - Boil 0.0  Hop     0.0 IBUs      

---FERM PROCESS-----------------------------
Primary Start: 5/8/2012 - 7.00 Days at 20.0 C
Secondary Start: 5/15/2012 - 10.00 Days at 18.3 C
Style Carb Range: 1.50-2.40 Vols
Bottling Date: 5/15/2012 with 1.9 Volumes CO2: 
Fermentation seemed to be over within 72 hours, so I started 
letting temp drop by one degree every 12 hours. This may not
 have been a good idae as FG ended up 1.019 instead of 1.014.
 Also ended up with 17.5L of beer instead of 20.

Taste Notes:
Overall the impression is of beer that is good, but past its prime. The carbonation was always a little light on this one, but when I tasted it it seemed particularly low. Don't know if that was just the specific bottle tough. 
Small stable head over translucent maple color 4/5
Aroma of some hops, caramel and brown sugar 6/10
Taste of some wood and light caramel medium body 6/10
Palate a little odd, and woody 2/5
Overall 12  Cumulative 29/50

This beer happened to also be reviewed by Keren MK in her blog where she says it was "Amber color, with aromas of malt and a touch of fruit, a little watery, bitter, with a grainy finish" (Translated from Hebrew). Others that have tasted this liked it a lot, but unfortunately, I don't have anything more detailed then "This is good" by way of review. :)

OOPS, Had a feeling I forgot something: The yeast used was English Ale Yeast (obviously). I used Dunstar Windsor, but I think it's no longer available in this country. I imagine Fermentis 04 would do a pretty similar job. (Thank Noam for the catch!)

Wednesday, September 5, 2012

What's common to a Chessmaster and Brewmaster?

I learned how to play chess when I was five years old. Took about fifteen minutes for my father to explain all the pieces and the way they move, and when he was done I asked him what else was there. He said that was it, and the rest was tactics and strategy. As a kid this annoyed me greatly: why would adults spent so much time thinking about a game who's rules I could recite in under a minute? Then my father showed me a whole (thick!) book about chess openings. WHY? What difference does it make what you start with?

Later, of course, I found out it makes a great bit of difference, and that arguably the opening is the most important part of playing chess. It is what sets you up for the rest of the game. A good opening may not guarantee a win, but a bad one can put you much closer to a loss. Brewing is a lot like playing chess.

It really is, too. Just like in chess you got the opening, the middle game, and the end game. And just like in chess, while the most spectacular action happens in the middle, you depend on a "good opening" to set you up.

So what's a brewing opening? To me, it's everything that happens until your wort hit the kettle. That is recipe, grain selection, milling, water, starter (you'll use that in the end, but you make it in advance), equipment building and maintenance, mash, luther, etc. Everything that happens between the moment you wake up at night with an idea for your next brew, until your wort is ready, is the opening.

And just like in chess, a great opening doesn't guarantee success, but a bad one can guarantee failure. You could have produced the best wort on earth, boiled it covered or scorched it, added stale hops or let it get infected, and ruin it. Or you could have done everything right in the boil and ferment, but over-sparged your wort and end up with beer full of tannins, mashed too high and end up with syrup, or just used bad tasting water and ended up with bad tasting beer.

There's several key factors in the opening that can effect your final beer. I'll try to discuss them in more details in future posts, but for now lets do an overview:

1. Recipe
This is where it all begins. Sure, you can just throw some grains and hops into the pot and probably come out with something fermentable. But if you are trying to make beer, and especially a  particular kind of beer, it helps to have a good recipe.
"Good" is the key word. You can get a ton of recipes just by browsing the web, but just because someone posts something online doesn't mean it's good. Finding yourself trusted sources for recipes would make your life much easier, but you should also understand how recipes work, how flavors mix, and how your particular ingredients and process will effect the final beer. When I published my recipe for my award winning IPA a month ago I had people telling me I was a fool. But the fact is that you will never be able to make my beer. The most you could do is to use my recipe to make your own beer. Your ingredients, your equipment, and your process will invariably be different than mine, and so your beer will be different. (It might, in fact, be better, but that's a different question).

2. Water.
Water makes up 99% of your beer. It's what all the sugars from the malt and all the alpha acids from the hops dissolve in. If your water tastes bad, your beer will taste bad. Unfortunately, if your water tastes good your beer may still taste bad. This is because the mineral composition of water effects the mineral composition of the beer, and not everything that tastes good in water will taste good in every kind of beer. For example: Water high in minerals (a.k.a "Mineral Water") can taste good. But put it in a Pilsner, or a light, malty beer, and it'll taste all wrong. Understanding your water, and how to adjust it to suite your particular beer, is crucial.

3. Equipment.
When you formulate a recipe, you are preforming a juggling act. You have to keep maltiness, bitterness, carbonation, body, mouthfeel, and flavors in perfect balance. You tweak it and tweak it until it looks perfect on paper. But then you brew it and it all falls apart. I had that happen the first time I tried to brew all grain: I researched and found that BIAB (which was what I was going to use) gets about 75% efficiency, so that's what I based my calculations on. Well, it turned out that my bag was all wrong, and I got 58%. All of the sudden, my big Belgian beer turned into a bizarre, over-hopped, over-spiced concoction (ok, truth be told, it was that before hand - never try to formulate your own recipe with three week's worth of experience..). The point is, I didn't know what to expect from my equipment, so all my fancy calculations weren't worth anything.

4.Ingredient storage and preparation.
This is the other side of knowing what to expect from your equipment: If your grain is crushed differently every time, than your equipment will preform differently every time. If you buy pre-crushed grain and then wait sometimes months to use it, it will preform differently than fresh-milled stuff. Ideally, you should always have your grain milled the same way, and close as possible to brew day. Likewise, when you buy hops you should pay particular attention to how they're stored. Hops that have been stored improperly (exposed to heat, oxygen, light, or humidity) will have dull flavors, lower alpha acid content, and in extreme cases can actually add nasty spoiled flavors to the beer. If you buy hops in bulk make sure you store them well, too. (BTW, this also pertains to yeast, but seeing as we're talking about the beginning stages of brewing, we haven't gotten there yet.)

5. Process.
Assuming your equipment is consistent, and your grain is milled the same, you can still get great variation in your wort depending on how you produce it.Sparging and luthing are major parts of this equation: the sparge method can impact your efficiency, and over-sparging can result in tannin extraction. Sparge temperature can also extract tannins. Grain-to-water ratio, mash method (infusion, decoction), water source and composition - All of these factors can change the efficiency, and composition of your beer, and make it more difficult for you to produce consistent results. 

There are, of course, many smaller parts to making a successful start for a brew day, and many things that come into play later are crucial for great beer (Sanitation, anyone?).  Hopefully we'll cover some of those in future posts. But before I end this one I would like to offer one last thought: When a chess player approaches a chess board, he is always starting from the same place - from scratch. Brewing is the same way: Your beer is the sum total of your decisions as a brewer, and every time you make a batch of beer you have the chance to make better, more informed decisions, and make great beer.