All Grain: Grain Absorbtion

BeerSmith has incorrectly calculated my pre-boil volume for several batches now and I finally decided to figure out why.

Normally, I use the tools in the recipe screen to calculate water volume (i.e. equipment profile). I hunted around and I found the "Water Needed" tool under the Tools section. I plugged in all of my equipment profile data and saw that it was calculating grain absorbtion. Since that was the only place that water could mysteriously disappear, and I hadn't been considering it in the past, I figured that was the place to look.

According to Designing Great Beers, page 64, the amount of water trapped in the spent grain is predictable: 80% water, 20% spent grain. He says that while you can weigh your spent grain, it is safe to assume that the grain weighs 40% of its original weight after mashing and sparging. You then multiply this value by 4, since there is 4 times more water in their than grain.

Let's use a recent batch as an example. I started with 7.03 lbs. of grain. After mashing, it should weight 2.812 lbs, and have absorbed 4 times that amount in water: 11.248 lbs. Water weights 8 lbs. per gallon (also according to Designing Great Beers, page 64), so that means I lost 1.406 gallons, or 5.624 quarts. I then used the BeerSmith "Weight to Volume" tool to find that water weighs 8.35 lbs. per gallon, and confirmed that value with a google search. So the real amount lost to grain is 1.347 gallons or 5.39 quarts. he also has a table that you can refer to (Table 8.1, page 64). When you look up '7' under 'pounds of grain mashed', you get 1.5 gallons, or 6 quarts. This is even more off than the hand calculation, which itself was pretty flawed.

Now let's try BeerSmith's "Water Needed" tool. I plugged in 7.03 lbs of grain and got 3.37 quarts of water lost. According to BeerSmith, they use a static amount of water lost per pound of grain and you can't change it. This is a shame because, as we are about to see, everyone's system loses different amounts of water to grain. BIAB, in particular, loses less water.

What did I actually get in practice? Let's go over my method. I mashed in with 10 quarts of water, lifted the bag out and held it over the pot while it drained. Then I placed it over a bowl on top of a cooling rack to drain while I poured the sweet wort into a bucket. Whatever drained into the bowl (a couple of ounces) gets tossed in too before I stirred and took a gravity reading. I repeated this same thing with both sparge batches. I did not squeeze, poke or otherwise fiddle with the bag.

I started with 20.5 quarts of water. I ended up with 17.75 quarts of water in the kettle. Loss to grains was thus 2.75 quarts: significantly less than either calculation. That means I lost 0.3912 quarts per pound, while BeerSmith assumed I would lose 0.4794 quarts per pound and Mr. Daniels suggested that I would lose a whopping 0.8 quarts per pound.

The lesson here is that you should not assume your system will *ever* produce the same results as someone else's, no matter how predictable they claim the value is. Take recommendations with a grain of salt, use them as a starting point and DO YOUR OWN EXPERIMENTS.

Why is this even important? If you end up with more water in your kettle after mashing, that means you either have to leave some out, thus lowering your efficiency, or boil longer, or end up with more beer with a lower gravity. Boiling longer is the only choice if you want to try and create the same beer you were aiming for, but that can be pretty unpredictable too.

edit: My new calculation of 0.3912 quarts of grain loss per pound worked flawlessly. On the very next batch, I got the exact boil volume predicted, give or take a few ounces measurement error.

Water: Chlorine, Chloramine and Chlorophenols, my nemeses

I hate chlorine, and you should too.

Most municipal water is treated with chlorine or chloramine to kill bugs. This helps to guarantee that the stuff that comes out of your tap won't kill you. The problem for brewers is twofold: deadly organisms can't survive in beer anyway, and chlorines can do bad things to the flavor of your beer.

Chlorine isn't so bad. Chlorine is volatile, and will leave your water pretty easily. You can either boil your water to remove it, or you can just let it sit out overnight. Furthermore, you can taste the chlorine in your water; no nasty surprises.

Chloramine is stealthier. You can't taste it or smell it. You won't know it's there unless you read your city's water report. You can only see if it you fill a large, white container with a very large volume of water, and even then it is  a very faint blue-green color that you might not even notice. Even worse, chloramine doesn't dissipate as easily. In fact, that's why cities are using it now: it is more likely to stay in your water, so they can use less and be sure that it keeps killing things all the way to your house. However, this means that it won't come out of your brewing water as easily as chlorine would.

Even if you don't use chlorinated brewing water, chlorine can get in your water if you sanitize with bleach and don't rinse adequately. Don't use bleach, just use a proper no rinse brewing sanitizer like Star-San.

If it is soooo hard to remove, why bother? The problem is that yeast produce special compounds called 'phenols'. Phenols are okay in certain amounts and in certain styles. They give Belgians and Hefeweizens much of their character, for example. Phenols can have a spicy, plastic-y, medicinal or clove-like flavor. You definitely don't want too much of that in most beers, *especially* the medicinal, band-aid like flavor.

The problem is that yeast eat chlorine and chloramine and produce 'chlorophenols'. These phenols have extremely low taste thresholds; you can taste them even if they exist in only a few parts per billion. Your beer will have a difficult to define 'sharp' or chemical flavor, and usually a plastic or band-aid aftertaste, like you just stuck your nose into a first-aid kit. If the amount is low enough, you might only be able to taste it when you burp.

My first batch ever used tap water. I used it as top-off to a Mr. Beer Classic American Blonde kit. After two weeks carbing, the first thing I tasted was green apple (acetaldehyde, generally a sign that you used too much simple sugar in your beer and haven't let it age long enough to compensate). The second thing I tasted was medicine.

I started using spring and distilled water, and the problem went away. Starting with my first all-grain, however, I decided to go back to using tap water. I learned that Campden tablets (sodium metabisulphite) could be added to remove chlorine and chloramine at a rate of 1 tablet per 20 gallons, so I used 1/4 to 1/2 tablet per batch. I did the same thing on all future batches: 9, 10, 11, 12, 13 and 14. Then I cracked open batch 8, and had an unpleasant surprise. Yep, medicine burps. My friend swore he couldn't taste it, but there was no sign of the taste in batches 2-7, while batches 8-10 all have it.

Blah blah blah, TLDR, so how do you deal with it? Here are your options, in order of cost:

If you're using chlorine, put all your brewing water in a big container (bottling bucket, mash tun, whatever) and let it sit for a day or two before using it. This does NOT work with chloramine. Cost: None.

Use one campden tablet. Do not bother cutting it in quarters. They say you only need a quarter tablet for 5 gallons, but look how well that turned out for me? There is no harm in using a full tablet, and these things are dirt cheap. Let it sit for at least 5-10 minutes before brewing, or a few hours, or all night like I do. Cost: Pennies.

Buy an activated carbon filter. By all accounts, this thing is the ultimate solution. Activated carbon removes chlorine and chloramine if you run your water through it at a very slow rate, between 2 and 5 minutes per gallon. Start your water flowing at 5 minutes per gallon (experimentation and experience will let you know what that is), set a timer for half an hour or so and come back when it beeps. The guys at MoreBeer use this method on our EBMUD water with good results, and I decided to just go for it instead of worrying constantly about my water. You have to use an activated carbon filter, not a 'brita' or 'pur' filter, and you should NEVER run hot water through it. Cost: $42.95 for the first year, $8.25 for replacement filters every year after that.

Use RO water from your grocery store. I'm sure you've seen the big water vending machine inside or out in front of the grocery store. They usually charge between 30 and 50 cents per gallon and either sell RO (Reverse Osmosis) or 'spring' water. RO water is extremely pure and lacking in minerals, so if you go this route for all grain, make sure you add brewing salts to make up for it. Cost: I use about 8 gallons per batch, and brew a batch per week. If I brew around 45 batches per year and buy my water at 35 cents/gallon at Safeway, that comes out to $126 per year. I also need to buy and store a big plastic jug to carry that water in (two, technically, since they only hold 5 gallons each).

You can also install your own RO system in your kitchen. These are generally expensive, require a lot of setup, and a lot of space for the system itself and the water tank. This is probably cheaper in the long run than bottled water, and is worth it over a carbon filter if your tap water has too many minerals in it or tastes disgusting. I'm not 100% sure if RO removes chloramine.

TLDR: Remove chlorine and chloramine from any water that touches your beer or brewing equipment - that includes sanitation water, just to be safe. Dont' sanitize with bleach. Remove chloramine with 1 campden tablet per 20 gallons or (preferably) an activated carbon filter at a very slow flow rate. I use the MoreBeer filter and a tablet in every batch now. Remove chlorine by letting it sit out a day or two, or any way that works to remove chloramine.

If I can beat this chloramine problem, that's one foe down. All that will be left is temperature control, evaporation rate consistency and fermentation temperature control.

Water: Evaporation Rate Again

I've been having a really tough time getting a consistent post-boil volume on my all-grain batches. My evaporation rate is inconsistent batch to batch despite using the exact same boil time, process and equipment.

For example:

Evaporation test with water: 5.9 quarts in 90 minutes.
Batch #13: 4.1 - 4.2 quarts in 90 minutes, so I ended up with 13.75 quarts instead of 12.
Batch #14: 0.6 quarts in 15 minutes, which is about 3.6 quarts in 90 minutes.
Batch #15: 5.8 - 5.9 quarts in 97 minutes, which is 5.4 - 5.5 quarts in 90 minutes.

All done with the same Winware 5 gallon pot on the same burner of my electric stove, and even adjusted to the same location on the burner within a millimeter of error. Humidity is generally about 55% here, and the temp has been around 72 on every brew day.

The only thing I can think of that is different is boil volume. More water in the pot takes more energy to maintain a vigorous boil. Given the anemic BTUs generated by my stove, the more water there is the less vigorous the boil will be, and thus less evaporation. Let's follow this line of reasoning:

Evaporation test: 18 boil volume, 5.9 loss in 90 minutes (maybe longer, I didn't get a warning when the water hit boiling since my stupid thermometer has an auto-shutoff 'feature'). This also may have included cooling loss, though. Plugging into BeerSmith actually gives 20%/hour, 5.4 quart loss, 0.5 qt cooling loss. Doh! Real result is 18 to 5.4.

Batch #13: 18.5 boil volume, 4.15 loss in 90 minutes. This is an anomaly; it is way too low.

Batch #14: 8.2 boil volume, 3.6 loss in 90 minutes. You'd expect this to be higher, rather than lower, if the 'vigorous boil' hypothesis is correct.

Batch #15: 16.9 boil volume, 5.4 loss in 90 minutes. Consistent with the original evaporation test, but with a lower boil volume.

I'll keep taking samples until I get something that actually works. For my next batch, I'll try 17.5 quart boil volume and an assumption of 5 quarts evaporation in 90 minutes.

edit:
Batch #16: 17.75 boil volume (higher than expected due to less loss to grain than predicted by BeerSmith), 5.64 loss in 90 minutes. Will try 17.9 boil volume next time.

edit:
Batch #17: 17.88 boil volume, 5.85 loss in 90 minutes. Will try 18.2 boil volume next time.

All Grain Brewing: Boil Trub and Boil Volume

Recipe size used to be simple. If I wanted to make 2.5 gallons of beer, I designed a recipe for that amount, boiled however much water I wanted, and topped off to 10 quarts with distilled water. I hit my OG every time and ended up with exactly 10 quarts in the keg. I'm learning more and more that it isn't so simple.

First off, when doing a full boil, there is no top-off. Sure, if you end up with less than intended you can top off a little, but you can't go the other way - if you have too much water, you can't just make it disappear. You'll end up with beer of a lower gravity.

Which brings me to number two, evaporation rate. This is tough. Evaporation rate differs based on how long you boil, the temperature, humidity and pressure of the room you're in, the pot you're using and what you're boiling. I suggested in an earlier post that you test the evaporation rate of your pot with water, but that is only an approximation. Beer wort will evaporate at a lower rate in practice than what you measured from your water test.

Let's say you have your evaporation rate down. After your boil, you have exactly 10 quarts of wort. Are you really going to dump all of that in? Hell no. You've got hops in there, absorbing up all your water. That isn't coming out. If you're doing all grain, you have *tons* of break material (reminder: cold break is the gray-ish material that separates from your wort when it cools). That break material should mostly stay in the pot if you can help it.

All in all, you'll be lucky to get 8.5-9 quarts of your boil. Sure, you could dump in all 10 quarts, but then you'll end up with more fermenter trub, which brings me to number four...

Fermenter trub. Stuff is going to fall out of your beer and settle during fermentation. When you rack to secondary or a bottling bucket, that material won't come with it, and your total volume of usable beer will be less. At this point, if you're doing a 10 quart all grain batch, you will probably have about 8 quarts, or 2 gallons.

The solution is usually to just make more beer. Design your recipe for 12 quarts (3 gallons). After your wort has cooled, remove as much boil trub as you can. You can either strain it out somehow or let it settle and only rack the clear wort into your fermenter. This means leaving 1-1.5 quarts in the kettle, and 10.5 quarts in the fermenter.

The method I use is to first create a whirlpool in the kettle while it is still hot by stirring the wort immediately after the boil and adding the aroma hops. Once the wort cools, break material and hops will tend to settle in the center in a cone. Then I transfer from the edge of the kettle, since most of the trub is in the center. I siphon from the kettle into a sanitized bucket. Then I allow the trub to settle out for an hour or two, or until I have at least 10-11 quarts of clear wort. With most beers, the difference between the trub and the clear beer will be very obvious. Tilt the bucket back to get the trub away from the spigot (make sure the spigot is sanitized!) and rack from the bucket to the fermenter with some tubing. Make sure, using the markings on your bucket, that you get at least 10 - 10.5 quarts in the fermenter. I generally end up with 2.5 gallons during bottling when I use this method.

Water: Evaporation Rate

Let's talk a little about evaporation rate. I'm going to define evaporation rate (or 'boil-off') as the volume of water that evaporates during a vigorous boil in a 1-hour period. This can be written as an absolute volume ('3 quarts') or as a percentage ('15%').

Why does this matter? If you are doing partial boils, it doesn't. You are going to top off your partial boil to the desired final volume anyway, so it really only affects how much you need to add. As long as you prepare more than you think you'll need (by adding gypsum, campden, pre-boiling, whatever) you'll be fine.

It matters a lot when you're doing full boils and all grain, though. If you want consistency and peace of mind, you need to figure out exactly how much water you'll be using, start to finish. BeerSmith has great tools that let you do this, but you need to give it accurate numbers first. Once you've configured BeerSmith, it will calculate exactly how much water you need to prepare, how much to mash and sparge with, how much will go into your boil kettle, and how much will come out.

The biggest problem with BeerSmith is that it treats evaporation rate as a percentage of total volume. Evaporation doesn't work that way. Evaporation depends on the heat (and thus, vigor) of the boil, atmospheric pressure and temperature, and the surface area of the water exposed to air. It does NOT depend on how much water you started with. If you boil 1 gallon of water in an hour when you start with 4 gallons, you will still boil off 1 gallon of water if you only have 1 gallon the pot to begin with.

I've made this mistake before, twice. First, I used a reasonable default of 15%, and ended up boiling much more than that. It turns out, the 15% value was for full boils of 5 gallon batches (7-8 gallon boil volume). Since my boils were actually half that, the 'percentage' was also half. This is a big clue that using a percentage makes no sense.

The second time, I calculated the evaporation rate of 3 gallons of water boiling for an hour, using my 6 gallon pot, to be about 0.9 gallons. This is 30% of the original 3 gallons. I plugged this into BeerSmith and it had me boil over 4 gallons. Unfortunately, 30% of 4-odd gallons is more than 30% of 3 gallons. I ended up still only boiling off 0.9-1 gallon, and had about a quart of extra water that never boiled off.

The best solution would be if BeerSmith stopped using percents for evaporation rate and allowed you to put in quarts/hour or gallons/hour. Until they fix that, here's what you do:

• Fill a pot with approximately what your typical boil volume will be. It doesn't have to be exact. For example, 4 gallons for a half batch full boil.
• Boil for an hour. Use the same heat level as you would during a real wort boil.
• Immediately remove from heat and place the cover on the pot. Let it cool.
• Carefully measure the remaining volume. Subtract the remaining volume from your starting volume. Call this your boil-off volume. For example, let's say you started with 4 gallons and ended up with 3 at the end. The boil off would be 1 gallon (4 quarts).
• Open up the equipment configuration screen in BeerSmith. Find the two boxes labeled Evaporation Rate and Boil Off. You can change Evaporation Rate, but not Boil Off. 
• Make sure you have configured your other values properly - top up water (0 for me), Final Volume (11 quarts for me) and Lost to Trub and Chiller (0 for me).
• Type 30 into the Evaporation Rate box. Notice that the Boil Off value changes automatically, and is probably way too high. For me, it reads 4.91 quarts.
• Keep adjusting the value in the Evaporation Rate box until it reaches exactly how much boil off you measured in your experiment. I tweaked the number down until the Evaporation Rate box read 25.86% and the Boil Off box read 4 quarts. Do this *every* time you change your final volume.
• The Boil Volume should now read the amount of water you need at the beginning of a one-hour boil, if you have checked Calculate Boil Volume Automatically. For me, it now reads 15.46 quarts.
• BeerSmith will now accurately tell you how much to sparge with and how much boil volume to use! Double check this volume on brew day - you may lose more or less water due to your own process, the time of year or the phases of the moon. Tweak this value up and down until you get consistent results every time. 

If you're curious, my Winco 20 quart stock pot has an evaporation rate of about 2.75 quarts in an hour or 4.14 quarts in 90 minutes.