You’ve got brewing questions. We’ve got answers.
How and why do I make a yeast starter?
You’re planning a big barleywine or lager, and want to make sure you have plenty of yeast to pitch. The ability to make a simple one-quart starter will go a long way to ensuring you get full attenuation, so let’s go over the basics.
We can go about it two ways:
We can time the starter so that when it’s time to pitch our yeast is through the lag phase and ready to start fermenting, which means making the starter ~18-30 hours before pitching.
Alternately we can propagate the yeast some days before, let it complete it’s life-cycle all the way through glycogen and trehalose uptake – important energy reserves it will need later. This can take anywhere from three to five days before the “beer” drops bright and the yeast is ready to go dormant, after which we can throw it into the fridge for 7 – 10 days. Then on brewday, we’ll bring it slowly up to room temperature, decant the starter beer and pitch the slurry.
The gravity can be anywhere from 1.035-55, but an easy number is 5oz extra-light or pilsner LME (4oz DME) in one quart of water. Add a few extra ounces of water to account for boil-off, simmer for 15 minutes and chill to below 70° before pouring into a 1/2g growler and adding your yeast. A rubber stopper and airlock are great, but a good-sized piece of (sanitized!) aluminum foil work fine. Lager and ale yeast will grow well at room temperature, but if you are making a very large starter to go into a lager, consider decanting the beer so as not to affect the profile of the finished beer.
Once your starter is working, you can just let it do its thing, but if you keep it handy and give it a gentle stir every hour or more, you’ll end up with more yeast. Lagers always can use a starter, and ales over 1.060 really need a starter to give you enough yeast to fully attenuate. As either of these get bigger in gravity so should the starter. A bock for instance at 1.065 OG can easily make use of a gallon-sized starter, though at that point you really will want to decant the starter beer unless the starter wort is basically the same recipe.
The standard rule is somewhere between .75 to 1 million cells per millimeter per degree Plato (~SG/4) for ales, twice that for lagers, and 75-100% more for lagers or ales over 1.065, but we will leave the math to the less-relaxed, less-notworried, less-havingahomebrew sorts.
So grab a bag of extract, mix up a starter of your favorite yeast and tackle that lager or big ale you’ve been dreaming about.
How can increase my mash efficiency?
Getting good efficiency in the mash is something we all-grain brewers strive for, but there are a few things to consider before discussing how to increase yours.
First of all, let’s look numbers and dollars: an average grain bill of 10# might get you an original gravity of about 1.055 with a 75% mash efficiency – a good number to shoot for. If you were to increase that to 80%, you’d save yourself a half-pound of grain. Conversely, 70% efficiency would cost about a half-pound of grain. We’re talking ~ 75¢ one way or the other. Now if you consistently hit 65% efficiency, you’re going to be forking over for another pound and a half to reach that 1.055 OG. An extra $2 per brew may or may not make you break a sweat, but at least now you have an idea of what you’re fighting for.
Second, we need to distinguish between brewery efficiency and extract efficiency. The former is the overall output versus amount of possible extract, but the latter is simply a measure of how well you get your sweet wort out of the mashtun. If you spill a cup of grain doughing in, have a half-gallon of deadspace in the bottom of your mashtun, and your kettle’s pickup tube leaves a quart of wort… none of these things can be helped by increasing mash efficiency. Similarly, poor mash efficiency can be mitigated with an otherwise very efficient system.
One last thing to get clear: accuracy of measurement. If you want to measure your efficiency, you need very accurate hydrometer and volume readings. Let’s take that 75%, 1.055 wort for example. If in fact you did not make 5 gallons, but 5.25 gallons (it’s not that easy to see a quart’s difference by eyeballing) then your gravity will be 1.052 and you’re wondering why you got 72% efficiency. If it’s 5.33 gallons, it’ll look like 70% efficiency. (It certainly works in the other direction, and when your buddy claims he consistently gets 85% efficiency, this is very possibly the culprit.)
So then, if you’ve determined that indeed you do have a low mash efficiency and want to bring it up a bit, here’s a few tips:
1) Sparge slower!
A common culprit of poor mash efficiency is what’s known as “channeling,” where the sparge liquor finds a few easy paths through the mash and into the manifold/pickup, bypassing much of the grain you’re trying to rinse. There are many designs out there for constructing a lauter; you may consider changing your setup if a very slow sparge (45 minutes for 5 gallons) does not help. Keeping the grain bed between 150 and 168° makes the sugars more soluable without getting so hot as to extract excess tannins. Sparge until your gravity hits around 1.012, even if it means boiling for a little longer. [If you’re a “batch sparger” this is not an issue, but for the same reasons it may be worthwhile to experiment with different sized sparge batches. Most brewers find that batching equal second- and third- runnings is a good compromise in time and efficiency.]
2) Stir during the mash.
If the mash has “cold spots” where the temperature or dilution of starches and enzymes are unequal, your conversion will not be as complete. Stirring the mash every 15 minutes can help this simple problem.
3) Hydrate your mash before doughing in.
By lightly moistening your mash (using as little as a half-cup to a pint per pound of grain) for 30 minutes before doughing-in proper, the starches are more readily accessible, allowing for more complete conversion during the window of time the enzymes are active. You’ll need to slightly adjust your strike temperature to compensate for the now-lower strike liquor volume.
4) Check your crush.
In general, the finer the grist is crushed, the better your extraction. There’s a point of diminishing returns however, since pulverized huskes will force you to also extract unpleasant polyphenols into the wort, and possibly give you a stuck mash. A “good” crush leaves the husks intact as much as possible while breaking up the starchy endosperm. Three-roller mills like the one at Hops and Berries will actually crack and then crush the grain in two steps with excellent results.
5) “Cut” the grainbed.
Once your vorlauft is finished and you’ve set your grainbed with a clear runoff, you really don’t want to muck around with that filter on the bottom. However many times, especially if you’re running off faster than optimum, the pull from the bottom will create “channeling” in the mash, where the hot liquor on top finds a few easy paths to the bottom, keeping the rest of the grains from getting rinsed well. It is possible to carfully reach down with the handle of your spoon, probe end of the thermometer, whatever you have, and cut a few lines forward and back, side to side, making sure to stay a couple of inches above the bottom of the grainbed, to decrease any channeling that may be happening.
6) Monitor your mash pH.
Amylase, the enzyme responsible for converting the starches in malt into sugars, need to be at around 5.2-5.6 to be most effective. The science of mash chemistry can be quite involved, so if you suspect this is where you need to improve, get ready to do some reasearch. There is a product from Five Star that when added to the mash maintains the pH at around 5.2, making short work of all of the calculations.
Hopefully armed with these few tricks you can squeak out at least a few more efficiency points, and get a better bang for your barley buck. Regardless, do not forget to RDWHAHB!
Why is my beer OVERcarbonated?
Every once in a while you may find a batch of beer that pours super-foamy and over-carbonated. You did everything the same as last time, but the bubbles are out of control. Here’s some possible answers:
1) fermentation wasn’t done, and the amount of “priming” you had in the bottle was effectively higher than you thought.
Solution: take gravity readings at the end of fermentation, make sure you have the same reading for three consecutive days before bottling.
2) you made less than a full five-gallon batch, making the ratio of priming sugar higher than the normal 1oz/g.
Solution: calibrate – at least roughly – where 5g is in your fermenter, adjust priming accordingly.
3) you have an infection in the bottle, of a microorganism that can ferment more than sacch cervisae. (Should be noticeable in the flavor of the finished beer, especially after a few months.)
Solution: replace all of your soft parts – tubing, gaskets, stoppers, etc., and thoroughly clean everything, soak in a mild bleach solution and air-dry completely, dry-dry-dry. (Don’t forget the spring in your bottle filler!)
If the beer tastes fine otherwise, you can get around the problem by chilling the bottles very well for a number of days (say, three days at 35°) and then carefully opening and recapping. This will relieve some of the excess pressure and let you pour the beer without filling the glass with foam.
Why didn't my beer carbonate?
Every once in a while we hear from someone who’s bottled beer doesn’t carbonate. I’m sure it’s very frustrating after all of the hard work and care put into it. Here’s a troubleshooting guide that might help.
As a general rule, an ounce of dextrose per gallon of beer at 70° will give you about 2.7 volumes of CO2, which is plenty. Minor adjustments will alter the carbonation level, but not to the point where you’d call it “flat.”
[E.g., 5oz in 5.5g at 75° will still give you almost 2.5 volumes.]
That bottle of beer sitting at 70° has most of it’s CO2 sitting in the headspace, so you really must get it cold for a day to let that gas go into solution, or else you’ll get a very satisfying “pffft!” when you open it, but the beer carbonation level will be low.
If you’re beer has been sitting for two weeks and seems undercarbonated, check the temperature and try to hold it between 70-75° for another week before chilling and trying a few bottles. It may be worth gently swirling each bottle sideways to resuspend the yeast that may have settled out.
If it is still flat, and you did indeed remember the priming sugar at bottling, then you should taste a definite saccharine sweetness to the beer, especially if you remember what it tasted like before priming and bottling. If it doesn’t seem to taste like it has priming sugar, but you know you put it in there, it could be a problem with your capper, caps or bottles. (Twist-off’s and used caps won’t work!) Otherwise it could be worthwhile carefully dosing another round of priming sugar into each bottle, using an eyedropper for instance.
A very strong beer may need fresh yeast at bottling time. If your undercarbonated beer is above 8% abv for instance, it may be worthwhile to grab a packet of dry yeast, hydrate a couple of teaspoons worth, and dose each bottle, carefully uncapping and recapping without introducing unnecessary oxygen into the beer.
Another reason you might want to pitch new yeast is if your beer has been in an extended secondary, say three months or more. At that point the yeast in there may simply have had enough, regardless of the alcohol content.
Either of the above repairs (more priming or more yeast) can be done either in each bottle, or by pouring the batch back into a bottling bucket. The oxygen introduced by pouring back into the bucket will certainly shorten the shelf-life, but it’s up to you which is easier or worth your trouble.
If none of this helps, and the thought of flat beer just doesn’t do it for you, there’s always the possibility of rebrewing a similar beer, dividing it between two carboys and carefully adding half of the uncarbonated beer to the fermenters just as fermentation is peaking. This will mitigate oxidization, and give you a second chance at fermented beer.
The final option, which ain’t the cheapest, is to get a kegging setup! One of the really nice things about kegging is that if your carbonation/conditioning doesn’t work out, you can simply force-carbonate and enjoy.
Hopefully this is useful to some of you.
How do I balance my draft system?
You’ve finally stepped up to kegging, so excited to pour your first homebrewed draft beer, but when you hit the faucet… you get a pint of foam. Or the beer pours so excruciatingly slow that you actually find yourself contoring your head, mouth underneath the faucet, hoping no one walks in. You need to balance your draft system.
In broad terms, the four things you need to work out are:
1) the beer’s carbonation level,
2) the beer’s temperature,
3) the amount of applied pressure and
4) the resistance between the keg and the end of the faucet.
That last factor is subdivided in two: static and dynamic, the first being how far above or below the keg your faucet is mounted – with each foot above the keg’s center being 1/2# of resistance, the latter being a function of your beer line – how thick, how elastic, how long. The vinyl tubing H&B sells for beer line has a restriction of about 3# per foot.
You will have to decide which of these four factors are inflexible. For most of us, the carbonation level is key, as is the beer’s temperature. However, unless you’re truly starting from scratch, your static resistance will be determined for you by where your faucets are mounted. Once you’ve decided upon the numbers you’re stuck with, the other numbers are simply a matter of math, reducing the pressure coming out of the keg down to near-zero at the faucet.
If for example you want to serve a 42° English Bitter at 2.2 volumes of carbonation, then a quick look at a carbonation chart (Google is your friend) will show that you must apply 9.9 psi at sea level to achieve that carbonation level at that temperature.
—For the math wizz, here’s the formula:
Pressure = F(Temperature, Volume)P = -16.6999 – 0.010105
Here in Ft Collins, at 5k’ we need to add about 2.5psi to this formula, giving us a total of 12.4 applied pressure. If our faucet is mounted at 4’ then we have all of our numbers except for (4b) – dynamic pressure. If we start with enough beer line to equal the pressure remaining then we can slowly shorten it until we arrive at an acceptable flow rate (which for most of us is somewhere around 8-10 seconds for a pint.) In this example, if the keg’s center is about 18” high, and our faucet it 4’, then we have 2.5’ of static resistance, or 1.25#. When we subtract that from our 12.4, we still have 11.15# to “soak up” in the tubing. At 3#/ft that’s about 3.9” of tubing.
For a second example, let’s consider a Belgian Dubbel that we want served at 3.0 volumes of carbonation. That’s quite a bit. We know that carbonation stays in solution better at colder temperatures, so in order to avoid long beer lines, we’ve decided to store this at 38°. Using this same draft system, we already know our carbonation, temperature and static resistance. The applied pressure to maintain that level of carbonation happens to be 16.7# at sea level, 19.2# in Fort Collins. Subtract our 1.25# of static resistance and we’re left to reckon with 17.95# of pressure. Using our same 3/16” ID tubing we’ll need right at 6’ to bring it under control. If we actually want to serve at 40°, we’ll need 17.9psi or 20.4 at altitude which, minus our 1.25 equals 19.15, requiring 6’5” of tubing.
One more example: Bavarian Hefe, 38° and a whopping 3.4 volumes. We need about 21# of applied pressure at sea level or 22.5# at altitude, which with our 2.5′ lift brings us down to 20psi. 6’10” of beer line should get us in the ballpark.
If this all makes sense, you’re ready to pull out a thermometer, calculator and tape measure, and get that perfect pour you’ve worked so hard for. Understand there may be slight differences in carbonation charts, but we’re only looking to get a few inches past where we need to be, and then adjust back to “perfect.” Equipped with this info, the homebrewer with a double regulator can easily carbonate lagers to one level, ales to another, simply by adjusting the length of the serving line. If the temperature restriction is too much for you, go for ale temps and keep frosted glasses handy for the lagers.
Want an easy(ish) way to save $7-8 bucks on your next batch? Wash and reuse your yeast.
[Note that there are many ways to skin this cat, and most of them will work as long as you keep it clean. Here is one method:]
Before racking your beer out of primary, prepare three cups of boiled and cooled (but not re-aerated) water, and both a quart- and pint- mason jar with lids and rings, all sanitized. Rack the beer, then immediately swirl and pour the yeast sediment into the quart jar, aiming for mostly clean slurry and beer, leaving hops and trub (aka “goop”) behind. If you can get 1.5 cups of thick slurry, great. Next, pour two cups of your clean water in with it, put the lid and ring on and gently swirl to mix. LOOSEN THE RING!!! Allow the mixture to settle for about twenty minutes, then carefully decant the liquid and the top quarter of the slurry into the pint jar. MAKE SURE THE RING IS NOT TIGHT! Dangerous pressure buildup could at least make a big mess, and at worst injure someone.
Keep in mind that even accounting for loss of yeast viability and remaining trub in the slurry, you’ll only need about 2.5 oz (or 5 Tablespoons) for a normal-sized beer. If you can get two or three times that much into the pint you’re golden. Use the rest of your clean water (or small beer – one of the few good uses for a cheap can of Bud Light!) to top up the jar, leaving as little oxygen as you can.
Conventional wisdom would say to use the yeast within a week, but two weeks seems to be a good cutoff, after which you really should feed the yeast with a small bit of starter replacing the water/beer in the jar. On brewday, carefully decant the liquid and discard, then pitch the top 2-3 oz of yeast into your chilled and aerated wort. You’ve just saved yourself 50% on yeast. Commercial breweries will do a similar procedure repitching 7, 10 or more times before starting a new culture, but this requires near-perfect sanitation, care and timing on your part.
How come my beer carbonated but has little or no head?
Head foam is basically made up of polypetides and water-soluble proteins (hence the common suggestion to add a bit of wheat for head-retention.) Some strains of yeast at higher fermentation temps will produce enough fusel alcohol to break down the head as soon as it can form. Also, detergent residue on your glass will inhibit foam, as will any oils from your hands, etc.
Stressed yeast (from not pitching enough into a big beer for instance) will secrete more protease than a healthy, happy yeast. This can break down the proteins in the beer and thwart attempts at a frothy head.
You can think of it like this: Beer has pro-head elements and anti-head elements. You need more of the former than the latter. If you pour a bottle of your problem brew into a glass, and then pour it into a second glass from about a foot high, you should either see a no foam (like a Sprite might do) or a large head that quickly dissipates. If it’s the former, you need more foam-positive constituents in your beer (e.g., raw flaked grains or wheat malt) and if it’s the latter make sure you have happy yeast, and the temperature range is within reason for that particular strain.
Also if you happen to mix up your bag of dextrose (fine, white, sweet powder) with your bag of lactose (fine, white, sweet powder) you most definitely will end up with flat beer! It has happened.