Hi Everyone,

The first club meeting of the year will be next week Jan. 21st at the Culver City Homebrew Shop starting at 7:30pm.

Culver City Home Brew Supply
4234 Sepulveda Blvd, Culver City, CA 90230

I really hope you’re all in for a good year! Your new and continuing board members have a lot of great stuff in the works. To start off:

Beer Style of the month we will be splitting into two parts as of now.

• One: the “Commercial Tasting Style” reflecting some of the new 2015 BJCP Style Guidelines. Where we taste Commercial beers of the monthly style.
• Two: the “Best Beer of the Meeting” competition. Where like in the past if you bring beers to the style of the month, the club would vote on the best beer of the night and you would win a $25 gift certificate from the Culver City Homebrew Supply. The difference this year is that the “Best beer of the Meeting” reflects similar or even different styles to the “Commercial Tasting styles”. Just Check out the Style page on the website for the latest monthly style guidelines.

This month in January will be “All Beer Style” for the best beer of the meeting for your chance to win the $25 certificate. Bring any beer you have that you would love to share.
Note: kegs/growlers/and bottles are all welcome to enter, but it helps to have enough for everyone to share and taste.

Next, We are adding some educational aspects to the monthly meeting. Starting off Michael Patterson will be presenting an “Off Flavor Sensory Test” each month until all the samples are gone from the kit. He will demo 1-2 commonly unwanted off flavors found in beer.  Demo will be at the start of the meetings from 7:30-7:45 or later.  Come early and learn!

Yes there will be Raffle at the January meeting!! What will be raffled off…… probably mostly beers and goods purchased from the Culver City Homebrew Supply Shop. The more Tickets you Purchase the more we will raffle off!

As we work out the details of the year and all the new anticipated events, we need your help too!!! Please feel free to volunteer.
Check out the “Commercial Tasting Styles” of the months to come this year. We would love to give anyone the opportunity to have a budget to go buy some amazing commercial beer and Host them at our monthly meeting. This Month your VP Michael Musgrave will be purchasing Januarys styles of English Bitters and Commonwealth beers. Please follow his lead.
We always need Homebrew for the club meeting of course, but for up coming events, like So Cal homebrew festival, Parties, and other pouring events. So Get Brewing!
Finally if you do have any denotable gear, beer, good, or other brewing related stuff for our raffles please bring it to the club meeting or events, or email anyone one of your board members or all of them at board@pacificgravity.com

Sorry I know that got long, but I had a lot to say. Here are the quick built points:

• Club Meeting January 21st start time 7:30pm @ Culver City Homebrew Supply
• New “Commercial Tasting Style” posted
• Return of “Best Beer of the Meeting” comp, bring beer win $25 gift certificate
• New Educational Demos at the beginning of the meetings, 7:30-7:45pm
• Yes, there will be a Raffle!
• We need Volunteers: for “Commercial Tasting Style” of the Month
• We always need more Homebrewed Beer!!
• We would love any Raffle Donations: Gear, Beer, Goods, or other Brewing related items.

Thank you all and hope to see everyone next week!

Special guest, Dallas Byerley of New Belgium Brewing will be joining us to sample their new seasonal release, Hoptober.  Please remember to bring some of your homebrew to share with us.  While you’re at it, bring some of your friends and maybe some new members.  As always we’ll be giving away lots of club swag and beer/brewing related goodies in our monthly raffle.  Your donations to the raffle are always welcome and needed.

With several club events and competitions upcoming, including the Stone Anniversary Road Trip and the Pacific Brewers Cup, we’ll have a number of sign ups and details to finalize. Of course we’ll also have the latest info on all upcoming club events, plan on joining us…

Answer:  A corn-like smell is usually due to a specific chemical compound called dimethylsulfide, or DMS for short.  DMS forms in the malting process and in the boiling process while brewing any beer.  It is the result of a thermal degradation of sulfur-containing amino acid in the grain called s-methylmethionine.   This amino acid is present in all malts.  Hence, all beers have some amount of DMS.

DMS is a highly volatile compound.  This makes it an easily detectable compound in aroma, even in trace quantities.  Fortunately, the volatility makes it fairly easy to scrub out of your beer.

The amount of DMS in your finished beer depends on a number of factors.  First of all is the amount of s-methylmethionine in the grain.  High protein malts such as six-row have higher amounts, hence more DMS.  Some of the DMS is driven off by heat in the kilning process.  Hence, the paler malts kilned at lower temperature have more.  These two factors combined contribute to the fact that pale lagers (made from pale six-row malt), often have high levels of DMS.  Not surprisingly, corn also contains a lot of s-methylmethionine.  These characteristics are a hallmark of lager beers.  A lager without DMS tastes rather bland.

The second factor that affects the amount of DMS is how much is removed from the wort during the boil.  Every bubble of steam that comes out of the kettle will carry some DMS with it.  Hence, longer boiling times and a more vigorous boil tend to reduce DMS levels.  For best results, you want to keep the boil rolling for the whole time.  Don’t simmer your beer!

The third factor that affects DMS levels is the rate at which the beer is cooled.  The decomposition reaction that converts s-methylmethionine to DMS is driven by heat.  Once you shut off the heat and start cooling the wort, scrubbing action of the steam is halted.  However, DMS continues to be formed until the wort is below about 160^oF.  Hence, a long steep will increase DMS.

The final factor (usually) is the amount of DMS that is scrubbed out during fermentation.  Carbon dioxide bubbles will remove some of the DMS.  Since more CO₂ comes off at higher temperatures, more is scrubbed out of ales than lagers.  Well-attenuated beers will be more scrubbed as well.

The plot above illustrates the potential DMS levels in your beer.  Here we assume a 90 minute boil, a 60 minutes whirlpool at flame-out, followed by cooling and fermentation.  The level of s-methylmethionine drops the longer the boil goes.  The amount of DMS can rise potentially to the ending level of s-methylmethionine at flame-out if the wort isn’t chilled.  Conversely, a rapid chill would lead to almost zero DMS.

If you’re not too careful about sanitation, you’ll find that some bacteria also contribute to DMS levels.  Coliform in particular is known to produce DMS.  Generally, though, it will also produce other foul odors such as mercaptan (natural gas smell) and hydrogen sulfide (rotten egg smell), making the DMS level the least of your worries.

Generally, if you keep your boil vigorous and cool rapidly, DMS levels will be appropriate for style.  However, the DMS level may still be too high for your taste.  If you keg your beer, you can artificially scrub out DMS using CO­₂.  This is best done before carbonating.  If you have a lager, allow it to warm to room temperature first.  Then, switch around the ball-lock fittings on your keg so they are backwards.  Hook up the long dip tube (labeled “out”) to the CO₂ tank.  Prop open the pressure relief and let the CO₂ bubble through the beer.  Slow down if it starts to foam out.   Occasionally sniff the gas as it exits the keg valve.  You should be able to smell the DMS at first, and then notice it fading with time.  After the level has dropped, switch the ball locks back to their usual configuration.   Then carbonate as usual.

Got a question for the Brewmaster?  Leave it in the comments section, or drop me a line at brewmaster@picobrewery.com.  Also, an archive of prior questions can be found at the Picobrewery website at http://www.picobrewery.com.