FAQ

This FAQ will be used to assist brewers in getting past first timer questions and over initial hurdles of brewing with bacteria and alternative yeast cultures. Please review this from time-to-time because it will be updated as often as necessary.

Quick Q&A

I have a question

Q. I am new. I want to learn more or have a question.

A: This wiki is a good place to search for answers, but you should also try to look up the answer to your question in the book "American Sour Beers" by Michael Tonsmeire. Many answers can be found in these two resources. If it is not, post your question in Milk The Funk!

My beer looks infected

Q: My beer looks infected. What contaminated it and what do I do?

A: Usually contaminated beers do not give favorable results. Exceptions occur rarely from wild contamination. If the contamination was from a cultured Brettanomyces that originated from equipment that was used for purposeful mixed fermentations, then the contaminated beer might turn out well. Otherwise, the chances of a wild contamination turning out good are very low. The best advice is to smell a sample of the beer, and if it does not smell good then dump the batch and brew a sour/funky beer on purpose (if the fermentation produces a fair amount of alcohol, it can be safely tasted after a month. See Safety for more information). If you have the space and time, and want to simply learn what will happen with accidentally contaminated beer, then feel free to keep the beer and see what happens. However, in the experience of most experienced sour beer brewers, this is not an efficient use of fermentation space. We recommend not wasting your time/fermentation space with accidental infections that show signs of off-flavors. Instead, use that space to brew an intentionally sour/funky beer and increase your chances of success. As far as knowing what infected the beer based on what a pellicle looks like, the short answer is that you cannot identify contaminating microbes based on what a pellicle looks like.

Is this mold

Q: Is this mold or a pellicle?

A: Mold is generally "fuzzy" or "hairy". Mold can also have color (green, red, black). See examples on our mold page to see the differences between pellicles and mold. Although many molds are not toxic, we recommend that beer that has been exposed to mold growth be dumped out because you can't be sure based only on what the mold looks like. Definitely dump any beer that has red or black mold growing in it.

I need a recipe

Q: I need a recipe for X style of beer.

A: The book "American Sour Beers" by Michael Tonsmeire has a great section on recipes. Also, we maintain a member-driven recipe database on Brewtoad: https://www.brewtoad.com/groups/milk-the-funk. We have a few recipes here as well.

Do I need separate equipment

Q: Do I need separate equipment for Brett/Pedio/Lacto beers?

A: There are many different opinions on this, but we will state here the best balance between practical and cautious advise. Brettanomyces can be cleaned and sanitized just like regular yeast. Bacteria such as Pediococcus can be a little more hardy, but they also still die from intense cleaning and sanitizing. Maintain a very good cleaning and sanitizing regiment, and you shouldn't need different fermenting vessels if they are glass or stainless steel, or kegging equipment. Plastic is prone to microscopic scratches, which can help bacteria survive cleaning/sanitizing regiments, so separate plastic fermenters for beers that have bacteria (Lactobacillus or Pediococcus) in them should be considered, but may not be necessary. Since cold side plastic equipment such as auto siphons and hosing are cheap, it is recommended to go ahead and get separate plastic racking equipment, airlocks, bungs, keg tap tubing lines, etc. Equipment that can be boiled can be re-used for clean and sour beers.

I have a question about pellicles

-See our pellicle page! Many questions can be answered there.

Q: I don't see a pellicle, is my beer OK?

A: The presence or lack of presence of a pellicle are not direct indicators of a good beer. A Pellicle forms when beer comes in contact with oxygen. Limit oxygen by taking samples only occasionally and if you have access to CO2, inject your fermentation vessel after pulling a sample. See pellicle for more information.

Q: How long does a pellicle take to form?

A: There are many variables and there is no one answer. It's all about the yeast and bacteria involved, O2 exposure, and time. Depending on all this, you may also never see a pellicle form. In the end, a pellicle only means there has been some exposure to an unknown amount of oxygen. Otherwise, pellicles have little meaning. See pellicle for more information.

Q: Do I need to wait for the pellicle to drop out before I package my beer?

A: The pellicle dropping out has no bearing on the readiness of the beer for packaging, nor the quality of the beer. Don't worry so much about pellicles! Instead, wait for a stabilized gravity for at least two months before packaging. See pellicle for more information.

Q: Is breaking the pellicle bad?

A: Although we recommend trying not to disturb the pellicle too much during sampling or moving the fermentation vessel, doing so isn't the end of the world. It will reform if oxygen is still present. If it happens, don't worry about it.

Q: I bottled a beer and now it has a pellicle. Is the beer ok?

A: Yes (assuming your beer intentionally had pellicle forming microbes). Pellicle formation is not uncommon in bottled beer. It is possible that the beer was exposed to some O2 during transfer/bottling, prompting pellicle formation. It is only an aesthetic issue and will go away over time, and you can induce this by disturbing it (gently shaking/inverting the bottle).

Can I use dregs from _____

Q: Can I use dregs from brewery X?

A: If the beer is not pasteurized, you can. Check The Mad Fermentationist's dregs list.

Q: What about if the brewery uses killer wine strains at bottling time?

A: First off, killer wine strains only kill susceptible S. cerevisiae. They do not kill Brettanomyces. Secondly, if the commercial beer is sour then the chances of the wine yeast still being alive are slim. Anecdotally, brewers have had great success with dregs from breweries who bottle wine yeast (for example dregs from Hill Farmstead). See the Packaging and Re-yeasting page for more details on killer wine yeast strains.

Why did my Lacto beer not sour

Q: My Lactobacillus based beer did not turn out sour or even the least bit tart. Why?

A: The biggest factor leading to lack of souring while using lacto is due to the amount of hops in your recipe. Even as much as 2-3 ibu's will inhibit lactic acid production. Try brewing or kettle souring with no hops. See Sour Worting for more information.

Why did my Roeselare beer not sour

Q: I used Roeselare (or some other commercial mixed culture) and it did not sour yet. What do I do?

A: Sometimes Roeselare and other mixed cultures don't get the acidity that you might want. If it hasn't been a year yet, waiting longer may help, but sometimes it doesn't. If after a year the acidity is not high enough for you, try adding fruit such as cherries or raspberries (or even fresh wort). The fruit has various acids in it, and the sugar content will partially be turned into lactic acid by the surviving bacteria (the brewer's yeast will be dead after a year). Brewing with no hops and a very high mash temperature (158°F-160°F) is highly recommended for next time. For more information, see Roeselare and Mixed Fermentation.

Can I use extract

Q: I am not am not an all grain brewer, can I brew sour beer with extract?

A: Absolutely! Many of our members have made excellent sour beer with unhopped extract. We recommend trying the MTF Gose recipe, MTF Berliner Weisse recipe, or AmandaK's lambic-style extract recipe.

How much fruit do I add and when

Q: How much fruit do I add to a sour beer, and what methods do I use?

A: Generally it is best practice to add the fruit after the beer has finished aging, and allow the beer to age on the fruit for ~2 months for beers that contain Brettanomyces (2 weeks aging time is fine for kettle sours without living Brettanomyces). See the Sour Fruited Beer wiki page for amount suggestions and specific applications.

What happened to my head retention

Q: How can I improve head retention in sours?

A: Contrary to the belief that acid is the cause of poor head retention, it is actually probably more due to the degradation of head formation proteins by Lacto. See the Lacto Foam Degradation page to see what you can do about it.

Will Brett clean up off-flavors

Q: My beer has off-flavour _____; will it go away if I pitch Brettanomyces?

A: It depends on the off-flavor. Typical yeast character such as moderate amounts of diacetyl, banana, clove, and other esters will often be changed by Brett. However, many other flavors from things like fusel alcohols will not. As the old saying goes, garbage in, garbage out. It's better to brew a clean beer and then add Brett, rather than try to recover a badly brewed beer by adding Brett.

Can I add Brett at bottling time

Q: Can I add Brett at bottling time to my beer fermented with only brewer's yeast?

A: Some people have gotten away with this, but unless you have experience with this, we don't recommend it. Brett will continue to ferment the residual sugars that Saccharomyces left behind in the bottle, and this could result in gushing or bottle bombs. One thing you could do is to take a sample of the beer, and add it to a jug with an airlock and pitch an overly large pitch of the Brett you are going to use into this sample. If possible, holding it at a warmer temperature and keeping it on a stirplate should speed up the process (a forced fermentation test). After two months (or sooner if held on a stirplate and held warm), measure the gravity change. Each gravity point gives you about 0.5 volumes of CO2. Adjust the priming sugar for the rest of the batch that you are going to bottle with Brett accordingly. Use bottles that are rated for higher pressures, such as Belgian bottles or sparkling wine bottles. Alternatively, you can rack to the beer into a fermentation vessel that you are comfortable exposing Brett to, add the Brett, and wait a few months for the gravity to stabilize.

Where did the mouse taint/Cherrios®/corn chip taste come from

Q: Q: Where did that Cheerios®/Cap'n Crunch®/Toasted cereal/corn chip flavor come from?

A: It can come from Brettanomyces or Lactobacillus. It generally appears after force carbonating in a keg and ages out in 2-3 months. See Tetrahydropyridine for details.

I used regular yeast and Brett, but my beer isn't sour

Q: I made a beer with Saccharomyces and Brettanomyces, but the beer isn't sour. What do I do?

A: Brett only makes a beer "funky" and fruity. It does not produce a lot of acidity. You need to brew a beer using a lactic acid bacteria such as Lactobacillus or Pediococcus. Check out the Sour Worting and Mixed Fermentation pages.

Alternative Bacteria sources (yogurt, probiotics, etc.)

Q: Will this bacteria source work? Has anyone tried souring a beer with this? What temperature do I use?

A: Check out Alternative Bacteria Sources for a list of what some members have tried so far and their experiences.

Q. How many GoodBelly shots do I need, and do I need a starter?

A: Use only fresh GoodBelly that has been stored cold, and don't bother making a starter. 1-2 shots (or 8 ounces from a 32 oz carton) is enough for ~5 gallons of wort (~20 billion cells for 5 gallons). The mango is generally preferred as it contributes very little flavor, but others can be used as well.

What temperature do I kettle sour at

Q: I am making a kettle sour beer. What temperature do I hold at for my bacteria?

A: It depends on your species of Lactobacillus. For example, L. plantarum (both the Omega Labs OYL-605 Lacto blend and plantarum probiotics) tends to prefer 70-95°F, and temperatures of 110°F+ can kill it. Check out our recommendations on the Lacto Culture Chart, Alternative Bacteria Sources, and the Sour Worting pages.

What pitching rate do I use for Lacto or Brett

Q: What pitching rate do I use for Lacto or Brett?

A: For Lacto, use around 500 mL to 1 liter starter volume for 5 gallons of wort. See the Lacto Starter Guide for more info. For Brett, it depends on if you are using Brett in secondary or primary. For secondary, no starter is necessary, although you may choose to make a starter anyway. For 100% Brettanomyces Fermentation lager pitching rates have been used with success. See the Brett Starter Guide for more information.

How do I maintain a culture

Q: How to I maintain a blend/a culture of ____?

A: The best way of storing your culture will vary depending on the organisms it contains and the resources you have available. See the pages for the relevant organisms for more information: Brettanomyces, Lactobacillus, and Pediococcus.

Can I repitch my sour yeast cake

Q: Can I repitch my sour yeast cake?

A: It is difficult to preserve the exact character of a blend, as the ratio of organisms will vary over time. Try repitching and see how you like the results. Pitching a fresh pitch of Saccharomyces yeast is a good idea.

Should I make a starter for commercial blend ____

Q: Should I make a starter for commercial blend ____?

A: You might want to if your commercial blend is nearing it's expiration date or wasn't handled properly, but making a starter may alter the proportions of the various organisms included in the blend, which may or may not effect the flavor profile of the resulting beer. Changing proportions is less likely with blends consisting of a single type of organism. See advice from Yeast Bay as an example of how to make a starter for a commercial blend.

When can I bottle/blend

Q: My beer is at 1.XXX---can I bottle it? Can I blend it?

A: The best guide is long term stability: if your gravity has remained stable between several readings, then your beer may be ready for packaging. However since the different organisms involved in sour beer production grow at different rates, a beer that was stable over a short period may begin fermenting again. Ideally you should look for stable gravity readings over a period of two months. When blending (especially with a non-sour beer such as a clean Saison), it is best to rest the blend in a fermenter for two months to make sure the gravity is stable. Don't assume that a low gravity clean beer such as a very dry Saison won't further attenuate once blended with a sour beer with Brett in it. See the Packaging page for details on how to package your beer.

I want to buy a ph meter

Q: I want to buy a pH meter. What is a good one to buy?

A: We recommend two tried and true models, the Hach Pocket Pro+ and the Milwaukee MW102. See PH Meter for more information.

I am traveling to _____, and want to visit some good breweries

Q: I am traveling to another state in the US. Any good recommendations on sour/funky breweries that I should visit?

A: Matt Miller maintains a map for just this purpose! Click here to check it out. Contact Matt on Facebook or on the map page to have a place added!

Plastic tubs as coolships

Q: I saw this rectangular plastic tub. It has a similar shape to a coolship. Can/should I use it as a coolship?

A: We recommend against using shallow plastic tubs as coolships. Most plastics are not food grade. And those that are may not be food grade at boiling temperatures. Also, boil kettles provide suffficient cooling rates as long as outdoor temperatures are cold enough. If you are looking to mimic commercial processes, then a homebrew-sized boil kettle has a surface area:volume ratio more similar to commercial coolships and will have a cooling rate more comparable to commercial producers. See the coolship page for more info.

Only pitched Lacto and it produced a krausen or fermented more than expected

We have two great pages that help you brew your first kettle sour. See the Sour Worting page, and the Lacto Culture Charts!

Q: My Lacto-only pitch has a krausen, or the gravity dropped more than a few points. Is this a yeast infection?

A: Yes. Yeast contamination is the cause of a krausen or drop of more than .005 gravity points. Even heterofermentative bacteria do not produce more than a little bit of CO2 blow off. The yeast contamination could have come from not enough cleaning/sanitation. There have also been numerous reports of yeast contamination problems from popular yeast companies. We recommend buying Lacto cultures from one of the smaller yeast labs. See this page for details.

Gose

So, you're looking to brew a Gose (Gose-uh)? A Gose has become a favorite first time tart beer to brew. The dominant flavors in Gose include a lemon tartness, a herbal characteristic from coriander, and saltiness (the result of either local water sources or added salt). Gose beers typically do not have prominent hop bitterness, flavors, or aroma. The beers typically have a moderate alcohol content of 4 to 5% ABV. Our Milk The Funk Gose is a great place to start.

Sour Brown Ale or Lambic

There are many approaches to these styles of beer. They can be difficult styles to make with traditional processes. We recommend reading this wiki page and deciding on a method to use.

Berliner Weissbier

Berliner Weissbier, or Berliner Weisse, is a light, tart, low ABV, and refreshing beer that originated in Germany. It has a simple grain bill consisting of mostly pilsner and wheat (although other adjuncts such as chit malt are sometimes used). It's a great style to choose as a first sour beer, but it's also a great style to have on hand for any brewer (especially in the summer time), and is typically soured with Lactobacillus. Check out the Milk The Funk Berliner Weisse page for an easy recipe.