Five Tips for Making Better Homebrew

2. One should try to cool the wort down to pitching temperature (< 80° F for ales and ~60° F for lagers) as quickly as possible. The reason for this is that once the wort temperature drops below 120° F it is susceptible to contamination; the longer the wort spends cooling to pitching temperature the greater the risk is of such contamination. It is, therefore, very important to cool the wort as quickly as possible. Although there still is some risk of contamination after the yeast have been pitched the yeast themselves take an active role in preventing this. After pitching the yeast set about increasing their numbers and making the environment unsuitable for most competitors (oxygen is quickly depleted, the pH is lowered, sugars are consumed, and alcohol which is toxic to most microbes is produced as a byproduct of yeast metabolism).

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3. In general, I would not recommend using just any dry yeast for pitching your wort if you are just starting out in homebrewing. My reason for saying this is two fold. There are a number of brands of dry yeast available to the homebrewer but, unfortunately, many of these brands are not of the highest quality. Secondly, there are relatively few varieties of dry yeast compared to the plethora of different varieties of yeast available in liquid form.

Although the quality of dry yeast available to the homebrewer has vastly improved over the past few years there are still a number of brands on the market which are of low quality with respect to viability and/or purity. From a technical point of view, it is not all the difficult to produce and package dry yeast which is why there are so many brands on the market. It is, however, much more difficult to produce a product that is pure and consistently of high quality. As a result, there are relatively few brands of high quality dry yeast in a market flooded with mediocrity. In contrast, there are relatively few manufacturers of liquid yeast. The overall quality of liquid yeast is quite high in terms of both viability and purity. One could pick a liquid yeast at random and have a very good chance of having selected a yeast that is of the highest quality. In general, one could not be assured of the same thing from the multitude of dry yeast brands on the market. Unless one has it on good authority that a particular brand of dry yeast is consistently of high quality then one is better off pitching with liquid yeast or perhaps one of the newer ready-to-pitch tubes of yeast paste.

The yeast strains available to the homebrewer in the form of dry yeast are somewhat limited and not nearly as varied as is the case with liquid yeast. To be available in dry form a strain of yeast must be able to stand up to the rigors of the drying process and yet still maintain a high degree of viability. This criterion greatly reduces the number of yeast strains that can be packaged in dry form, thus resulting in fewer varieties of dry yeast on the market. Often the manufacturer of dry yeast will have only a single ale yeast and and may or may not even have a lager yeast; there are very few genuine lager yeast available in dry form. The dry yeast that are available to the homebrewer are general all-purpose yeast. These yeast are will produce fine bitters and pale ales but most lack the character to produce some of the more "exotic" beer-styles. This is changing but still the number of dry yeast avaiable to produce lagers, weizens or Belgian-style beers is quite limited. Also considering the great impact yeast can have on the flavor profile of finished beer having only a few ale yeasst to produce bitters is rather limiting when you consider that most brands of liquid yeast have at least a half a dozen strains suitable for bitters and pale ales. Because of the relatively large number of low quality brands of dry yeast on the market and the lack of much variety in even the best of dry yeast brands I would recommend one use the more reliable and diverse liquid yeast for pitching.

I am, of course, not saying that all dry yeast are of poor quality. There are some very good dry yeast on the market but, unfortunately, they are the exception rather than the norm. I have heard some very good things about DCL yeast (i.e. Safale. Safbrew and Saflager) , Danstar yeast (especially their Nottingham Ale yeast) and Muntons Premium Gold Ale Yeast . Dry yeast do have an important place in my brewery. It is good to have a few packets of dry yeast around in case of emergencies. For example, you may accidentally kill off the yeast by pitching it into wort that is too hot. In cases like this dry yeast can come to the rescue. The ease of storage makes dry yeast ideal for serving as insurance policies against brewing mishaps.

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4. If a recipe calls for a substantial amount (> 10% of the total) of sugar one should substitute light Dry Malt Extract (DME) for the sugar. One wishes to use light extract for this purpose so as to minimize its color contribution to the finished beer. The predicted extract for DME is about 1.045 which means that one pound of DME in one gallon of water will produce a solution having a specific gravity of 1.045. The predicted extracts for cane and corn sugar are 1.046 and 1.037 respectively. Therefore, if a recipe calls for cane sugar making a simple one to one substitution of DME for cane sugar will produce the desired results. Should a recipe call for corn sugar making a simple one to one substitution would result in a wort with too high an original gravity. One should use 17.8% less DME than corn sugar. For example, if a recipe calls for 1 lb. of corn sugar then only 13 oz of DME would be required to achieve the same gravity.

One could, of course, also substitute the sugar in a recipe with light Liquid Malt Extract (LME). Since the predicted extract for LME is 1.038, one should be able to simply make a one to one substitution of LME for corn sugar. On the other hand, if one substitutes for cane sugar then one would need 21% more LME than cane sugar (i.e. 1 lb. of cane sugar corresponds to 19.4 oz. or 1 lb. 3.4 oz. of LME).

Note, however, that unless an entire package of LME is required, storage of the remaining extract can be problematic. DME is generally preferred over LME for making extract substitutions because of the ease at which DME may stored and the fact that light DME tends have less color contribution than light LME.

•••When substituting DME for LME one should use 15.6% less DME than LME (i.e. 1 lb. of LME would be equivalent to 0.84 lb. or 13.5 oz. of DME). Alternatively, when substituting LME for DME one should use 18.4% more LME than DME (i.e. 1 lb. of DME would be equivalent to 19.0 oz. or 1 lb. 3.0 oz. of LME).

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5. Pitch a large enough quantity of healthy, viable yeast. The metabolic activity of yeast will create an environment that is ill-suited to most other microorganisms; the oxygen is quickly depleted , the pH is lowered and there is a build up of a toxin known as ethanol. However, to actually suppress the growth of competing microbes the yeast must be present in the wort at a concentration of at least two-million yeast cells per milliliter of wort or a total of 40-billion cells for five gallons (Farnsworth, 1989a).

Unless you are using one of the pitchable yeast packs/tubes or reusing yeast from a previous brewing (see below) you will need to make one or more yeast starters to obtain the appropriate yeast concentration. Although dry yeast do not technically require yeast starters, they do, however, require some preparation prior to pitching; dry yeast should NOT be pitched directly into the wort. During rehydration the dry yeast are fairly vulnerable and the antiseptic quality hops impart to the wort can actually reduce the viability of the yeast at this stage. Fortunately, once the yeast are hydrated this is no longer a problem. Therefore, the dry yeast should be rehydrated prior to pitching. For five gallons of wort about 10-15 g of dry yeast should be rehydrated and pitched. For high gravity beers and lagers one should double the amount of yeast used. To rehydrate dry yeast you should first sanitize about two cups of water by boiling it for about 15-20 minutes. Cool this water to ~100° F and add the dry yeast. After 10-15 minutes the yeast will be rehydrated and are therefore, ready for pitching (Farnsworth, 1989a).

If you are using liquid yeast in standard "smack-packs" or tubes, the concentration of yeast should be increased substantially prior to pitching. Admittedly simply pitching the liquid yeast once the smack-pack has swollen to its maximum extent can ferment five gallons of wort reasonably well. However, when doing so there tends to be an extended lag time before fermentation starts in earnest; during which time the wort is quite susceptible to contamination. For five gallons of typical gravity wort one should pitch the yeast from about 1-2 quarts of starter wort. In the case of high gravity beers or lagers you should use the double this amount (i.e. 1/2 to 1 gallon of wort).

When using liquid yeast you should increase the quantity of yeast through a series of small increments rather than making a single dramatic increase in wort volume. It is generally recommended that at each step the volume of the wort should not increased by more than a factor of 10. For example, the volume of a Wyeast smack-pack is 50 ml so you should not increase the wort volume in a single step to more than about 500 ml or 16.9 oz.

To make a ~16 oz. starter one should added eight rounded tablespoons (1/2 cup) of DME or 10 tablespoons (~2/3 cup) of LME to about 2 1/2 cups of boiling water, stirring constantly as you do so (Farnsworth, 1989b). Add a few hop pellets to the wort boil for ~20 minutes and stir frequently. Use of low alpha acid hops is recommended for making starters so as to make use of the antiseptic quality of the hops while not contributing much additional bitterness. After the starter wort has cooled down it should be added to a sanitized fermentation vessel and the liquid yeast pitched.

For this size of starter 22 oz beer bottles or 1000 ml Erlenmeyer flasks make very good fermenters for starters. In both cases drilled bungs and be used to fit airlocks onto the bottles or flasks. I have also found that simply placing a sanitized balloon piece of over the mouth of the fermenter (bottle or flask) also works quite well. Note you should swirl and/or shake the starter to ensure proper aeration before placing it in a warm place and allowing fermentation to proceed.

Since you should pitch the yeast from at least one quart of starter wort for a typical five gallon batch of beer you will need to make an additional starter to obtain the proper yeast concentration. In the example above the initial starter would have a volume of about 16 oz. so one should be able safely increase the starter volume up to as much as 160 oz. or five quarts. For typical five gallon batches, I generally pitch the yeast from a 2 quart starter. To make such a starter you would mix 2 cups of DME or 2 2/3 cups of LME in about 80 oz. (five pints) of boiling water and prepare in the manner described above for the 16 oz. starters.

One gallon glass jugs make very good fermentation vessels for fairly large yeast starters. Of course, one may also use one or more large (> 1000 ml) Erlenmeyer flasks this purpose. In both cases bungs fitted with airlocks or large sanitized balloons (or lacking that sanitized pieces of aluminum foil) should be placed over the fermenter openings.

There has been considerable debate regarding exactly when one should pitch a starter. There are two conflicting views on this. One opinion is that one should wait until starter fermentation has gone its course and then one would decant most of the liquid and pitch the yeast sediment. The idea behind this is that by waiting for fermentation to run to completion one is maximizing the yeast population in the starter. The other camp suggests pitching the entire starter when it is at high kraeusen. Although the population of yeast would be lower the relative lag time from pitching to active fermentation should be reduced since the yeast are already actively fermenting. I tend to favor the latter method though it does require timing things correctly.

For convenience one can make starter wort in advance for later use simply by canning some wort. For this purpose using a pressure cooker to sterilize the canning jars, rings, lids as well as the wort is essential. Although there are no known pathogens that can survive in beer the same is not true of canned wort. The sweet wort is an ideal growth medium for most microbes including those that can produce botulism and other illnesses. Employing proper canning techniques, including the use of a pressure cooker, can greatly reduce the possible risk of illness.

Another quite simple way to be assured of having sufficient yeast is to work out your schedule such that brewing and beer transfers coincide with each other. Basically, one wishes to transfer beer from the primary to the secondary fermenter and then rack the freshly brewed wort, after proper cooling, of course, onto the sediment left behind in the primary fermenter. A typical five gallon batch will usually yield about a quart of sediment in the primary. This sediment is comprised of mostly yeast though trub is also present as well as the remains of any hop pellets that may have been used during the brewing. One quart of this sediment should provide more than enough yeast to ensure rapid and vigorous fermentation of five gallons of wort. It is generally recommended that one should not repitch yeast in this way more than about seven times.

One could also repitch the yeast sediment from the secondary fermenter. This sediment would generally lack trub and hop remains present in sediment taken from primary fermenters. However, there would likewise be fewer viable yeast present in this sediment. Also, since these yeast would be harvested fairly late in the fermentation they may not be nearly as strong and healthy as those yeast taken from the primary fermenter; their food reserves (i.e. glycogen) most likely would have been, at least partially, depleted which could result in greater lag times and therefore, a greater likelihood of contamination. For these reasons, it is generally considered better to use the yeast sediment taken from primary fermenters rather than using that taken from secondary fermenters.

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Farnsworth, P., 1989a, Healthy Homebrew Starter Cultures: Zymurgy, v. 12, n. 4, p. 10-13.

Farnsworth, P., 1989b, Yeast Stock Maintenance and Starter Culture Production: Zymurgy, v. 12, n. 4, p. 32-35.

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