You’re brewing a beer and it tastes just fine after primary fermentation. You move it to secondary, bottle it, and when you go to taste it…butter bomb! This sounds like a problem with diacetyl.

What is Diacetyl?
Diacetyl is a natural byproduct of fermentation. A small amount of diacetyl is acceptable in certain beer styles, most notably in a variety of ales and a handful of lager styles, but most lagers should not present any diacetyl. Excessive diacetyl in any beer can be a defect.

Causes of Diacetyl in Beer
Diacetyl is produced when beer is fermented. Diacetyl can be produced in excess when yeast is stressed, such as when fermentation temperature is too high or wort isn’t sufficiently aerated. Diacetyl can also be caused by bacterial infection.

Determination of Diacetyl in Beer
Diacetyl is detected as a butter taste in the beer’s flavor and aroma.
The challenge is that there may be a diacetyl precursor in a sample of beer that you can’t taste or smell: acetolactate. So how do you test for diacetyl when it isn’t actually present in your beer? How do you catch the diacetyl before it’s too late?

How to Test for Diacetyl in Beer

1. Using cleaned and sanitized equipment, pull two small (~2 oz.) samples of wort from the primary fermenter and cover them with aluminum foil.

2. Place one in the refrigerator and the other in a hot water bath. The heated sample should rest at 140-160˚F for 20 minutes.

3. Place the heated sample in the refrigerator with the other sample (or in an ice bath).

4. When both samples are chilled, take them out for a taste. If you can taste diacetyl in the unheated sample, there is diacetyl in your beer. If you can taste diacetyl in the heated sample but not the unheated sample, your beer has acetolactate, which was converted into diacetyl by the high temperature. In either case, do a diacetyl rest. For an ale, this may just be a couple extra days in the primary fermenter. For a lager, you should increase the temperature of the beer to about 60˚F, which will help the yeast “clean up” the diacetyl in your beer.

Tips for Preventing Diacetyl in Beer

• Clean and sanitize equipment thoroughly to prevent infection.
• Shop for beer yeast depending on diacetyl production – check the manufacturer’s website.
• If brewing with a high amount of adjuncts, consider using supplemental yeast nutrient.
• Aerate wort well, using pure oxygen if possible.
• Pitch an adequate amount of healthy, viable yeast.
• Keep fermentation temperature within the yeast manufacturer’s specifications.
• Perform a diacetyl rest after primary fermentation. In the case of lagers, raise the temperature to 60-68˚F for 2-3 days before transferring to secondary and cold conditioning.

Have you ever had issues with diacetyl or a butter taste in your beer? What have you done to remedy the situation?
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David Ackley is a beer writer, brewer, and self-described “craft beer crusader.” He holds a General Certificate in Brewing from the Institute of Brewing and Distilling and is founder and editor of the Local Beer Blog.

Does it matter which type of beer glass you serve your beer in? Well, often times, no – no one wants to be a snob – but once in a while you want to get the full effect of your brew. This is where the different beer glass types come into play.
Proper beer glassware enhances the positive aspects of your homebrew, with different types of beer glasses highlighting different qualities.
Try this: take a very fragrant beer like an IPA or barrel-aged stout and pour some of it into a regular pint glass and some into a tulip or wine glass. Smell the two and compare the aromas – you’ll probably notice a significant difference. This experiment also works with wine and liquor.
So what are some of the different beer glass types and their uses? Below we’ve put together a somewhat comprehensive list of the glasses you’ll run across when drinking your brews. This is a menagerie of glasses that you may want to consider having on hand when serving you your own homebrews.

Goblet – Ideal for Belgian ales and Berliner weiss, the goblet features a wide mouth for easy access to the beer’s complex flavors and a structure that supports head retention.

Flute – A flute is a narrow beer glass that tapers towards the bottom. The shape gives the viewer a good look at carbonation and helps release the pleasing aromas of gueze, lambic, swarzbier, and Vienna lager.

Pilsner – The pilsner glass is similar to the flute, but it has a wider mouth. The change in shape showcases color, supports head, and encourages aromatics of – not surprisingly – pilsners, but also blonde ales, bocks, and witbier.

Pint Glass – Of all the beer glass types, this is the all-around go-to glass. It is versatile as it is common and is ideal for many of your favorite beers, including amber ale, altbier, English bitter, brown ale, IPA, porter, and pumpkin beer.

Snifter – The snifter, just like what you would use for brandy or cognac, is a smaller version of a goblet with a lip that turns inward, capturing desirable aromatics. Snifters are smaller than most other glasses, making them a good fit when drinking higher gravity beers. Use a snifter when enjoying barley wine, Belgian dark strong ale, double IPAs, imperial stouts, and tripels.

Stange – A stange is a relatively narrow beer glass type with no taper. It concentrates aromas into a narrow channel and gives the drinker a good look at the beer. Stange glasses are appropriate for a number of styles, including altbier, bock, gose, lambic, and rye beer.

Stein – In German, “stein” means stone. For years prior to the widespread use of glass, these large mugs were made of stone. Go to Germany today and ask for a “Mass stein” – they’ll give you a full liter of suds. Steins work great for Oktoberfestbier.

Tulip – The tulip is on of the great all-around beer glass types for evaluating your homebrew, regardless of style. The glass’s shape gives a good sense of color, enhances aromas, and holds a big head. The tulip works especially well for saisons and other Belgian styles.

Weizen Glass – The weizen glass is designed for wheat beers. Its size allows for a large serving of the refreshing beer and a big, wheaty head while also helping to enhance aromas. Use a Weizen glass for all types of wheat beer.

So there you have it, the different beer glass types and their uses! Don’t get too hung up on choosing the appropriate glassware – and definitely don’t shame other people for using the “incorrect” beer glass. The most important thing is to always appreciate the beer!
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David Ackley is a beer writer, brewer, and self-described “craft beer crusader.” He holds a General Certificate in Brewing from the Institute of Brewing and Distilling and is founder and editor of the Local Beer Blog.

Have you ever wondered what was the reason for boiling a wort?
The boil is an aspect of homebrewing that can be taken for granted as a step simply for throwing in the hops, but there are actually several reason for boiling a wort:

• To sterilize the wort
• To stop the enzymatic activity of the mash
• To concentrate the wort
• To boil off unpleasant aroma compounds
• To coagulate proteins so they will drop out
• To extract bitterness from the hops
• To adjust wort color and flavor

All these reasons play a significant part in the final outcome of the beer. It’s color, bitterness, flavor, intensity, over all character are partially a factor of the boil. Let’s briefly cover each reason for boiling a wort.

1. To sterilize the wort
   As homebrewers, we want as much control over our beer as possible. Beer yeast is (usually) the only thing we want growing in our beer. Boiling the wort kills off any microorganisms that may be in the wort or other ingredients. Sterilization requires a minimum of about 20 minutes of boiling.

2. To stop enzymatic activity
   A brewer can control the ratio of fermentable and unfermentable sugars, mouthfeel, and other factors by their command over the mash. Changes in temperature and pH can make a big difference in the enzymatic activity during the mashing process. By heating the wort to a boil, the enzymes in the mash stop their activity and the mix of sugars in the mash is fixed.

3. To concentrate the wort 
   The wort collected after the mash is never the brewer’s intended original gravity. By boiling the wort and knowing one’s boil-off rate, a brewer can execute a precise original gravity for their beer. In many cases a 60-minute boil is sufficient for reaching a desired gravity, but sometimes a longer boil will be required.

4. To boil off unpleasant aroma compounds
   Dimethyl sulfides, commonly referred to as DMS, are compounds produced while boiling a wort and their presence in beer is considered a fault. You might recognize DMS as an aroma similar to cooked vegetables. One of the major reasons for boiling a wort is to get rid of these offensive compounds. A long, vigorous boil will vaporize the DMS. For this reason it’s important to boil the wort uncovered. Aldehydes can also be boiled off.

5. To coagulate proteins
   There are a number of materials in malt, particularly protein, that are suspended in wort. The boil helps these proteins coagulate into larger chunks, which form during the hot break and will settle out during the cold break. Irish moss can aid in this process.

6. To extract bitterness from hops 
   The part of hops that are responsible for bitterness are called alpha acids. In order to contribute bitterness to beer, these alpha acids must be isomerized (a change in chemical structure), which only happens during boiling of the wort.

7. To adjust wort color and flavor
   In some cases, boiling wort can help achieve a darker color and a rich, caramel flavor in the wort. The chemical process responsible for these changes is called the Maillard reaction.

So there they are, 7 reasons for boiling a wort. Can you think of any other reasons we boil wort? Please share them with us!
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David Ackley is a beer writer, brewer, and self-described “craft beer crusader.” He holds a General Certificate in Brewing from the Institute of Brewing and Distilling and is founder and editor of the Local Beer Blog.

Are you feeling restricted by the size of your brew kettle? Do you want to brew 10, 20, or 30 percent more beer without buying any new homebrewing equipment? Fortunately, there’s a way you can by using a process called high gravity brewing.
Many home brewers start out with a five-gallon brew kettle. It works great for brewing extract and partial mash beer recipe kits – and it’s easy on the budget. But if you’re trying to advance to all-grain brewing – whether with brew-in-a-bag or with a mash tun cooler – it can be hard to brew a full five-gallon batch of beer with the five-gallon kettle. Luckily, there’s a way to “cheat”: brew a higher gravity beer and dilute it down with water after the fermentation.
Just like we do with extract and partial mash brewing, it’s perfectly acceptable to dilute your wort or beer with water to make it go further. Alternatively, you can use this high gravity brewing process to take your five-gallon batch of beer (or any size batch for that matter) and dilute it to make more.

Here or some basic high gravity brewing tips:

• Water should be pre-boiled to sterilize and de-aerate it, and then chilled to match the temperature of the wort or beer.

• Keep your dilution rates to a reasonable level. Around 20% is okay, and up to 40% would be fine with certain beer styles, doubling the batch size is not realistic.

• Blending down your wort pre-fermentation may lead to higher ester production. Depending on your beer recipe, you may prefer to blend after fermentation.

• When diluting your beer after fermentation, avoid splashing. Splashing can introduce air back into your beer, which negatively impacts shelf life.

The high gravity brewing process couldn’t be easier. To amp up your five gallon recipe to a six gallon recipe, simply increase your ingredients by 20%. (If desired, use a brewing calculator to calculate hop changes to account for the change in hop utilization.) Depending on your beer recipe, you may need to tweak your yeast pitch rate, but in most situations you won’t need to worry about it. After fermentation, add your gallon of pre-boiled, pre-chilled water to either the secondary fermenter or the bottling bucket, taking care not to splash. Siphon the beer into the water to mix it together.
If you’d like to experiment, you can even bottle part of your batch at the original strength and the rest at the diluted rate. It takes a little extra time to figure out the blending ratios, but luckily there’s an easy formula!

Blending Formula For High Gravity Brewing

Use this formula to calculate how blending or diluting the wort or beer will change your gravity, IBUs, alcohol content – even beer color:
A₁ * B₁ = A₂ * B₂

A₁ = gravity, IBUs, ABV, or color (SRM) of the first beer
B₁ = volume of the first beer
A₂ = gravity, IBUs, ABV, or color (SRM) of the second beer
B₂ = volume of the second beer

It doesn’t matter which recipe is the “first” or “second” beer, as long as you don’t mix up your stats between the two.
So, for example, the beer you want to make has an expected ABV of 5% (A₁). You want to end up with six gallons of the beer (B₁). At what ABV (A₂) should you brew your five-gallon batch (B₂) in order to add one gallon of water and end up at 5% ABV?

5 * 6 = x * 5

x = 6% ABV

The calculation also works for gravity. You want your wort to have an OG of 1.040, but you have five gallons of wort at 1.050. How much water should you add to reach 1.040? (Use gravity points: 1.040 becomes 40.)
40 * B₁ = 50 * 5
Answer? Your target volume of wort should be 6.25 gallons, so you should add 1.25 gallons of water.
The advantages of high gravity brewing are many: less equipment, less space, more variety… But beyond this, it’s easy to do and doesn’t require any significant, additional effort on your part.  So I say, why not give the high gravity brewing process a shot and see what you come up with!
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David Ackley is a beer writer, brewer, and self-described “craft beer crusader.” He holds a General Certificate in Brewing from the Institute of Brewing and Distilling and is founder and editor of the Local Beer Blog.