Got an email from a reader with a question about aeration and yeast. Any further reader input would be welcome…

Hey Scott,
Just found your blog,  while searching for the origins of the dark IPA.  I’m going to attribute it  to Greg Noonan just like every Vermonter should.  I’ve been trying to get  better with homebrewing and have been a little concerned with aeration of the  wort going into primary.  I’m a PhD student in biobehavioral neuroscience  so I get a bit anal about things, bear with me.  As a scientist I want a  specific value for dissolved oxygen necessary for a good fermentation, I find  that nowhere.  Some suggest a vigorous shaking of the wort, I’ve read of  aeration systems (access to medical 95%02, 5%CO2 so I’m tempted), and I’ve also  read many that like you suggested transferring the wort so that it is a bit  splashy and aerates “enough” (the scariest option for me as a scientist, I need  control!).  Is a good pour typically enough to provide enough oxygen for a  healthy ferment?

Enjoying the reading material you provide.  Thanks!
Brendan

Hey Brendan, thanks for checking out the blog! Glad you’re enjoying it.

As you probably can figure out from my posts, I am NOT much of a scientist – I have no idea what kind of dissolved oxygen ratio would be ideal for optimum start-up. I have, for my entire brewing career (20 years) observed that pouring the wort into the fermenter and allowing it to splash well has been more than adequate. For a short while I used a counterflow wort chiller, siphoning the wort through copper into the bucket, and I am absolutely certain that there was not enough aeration occurring then – I had several batches that took days to start, and ultimately had off-flavors that one would associate with lag spoilage bacteria… Using the “pour and splash method” I usually get active fermentation within 4 – 6 hours, even quicker if I have built up a starter slurry…I don’t have my copy handy right now but I’d bet if anyone has quantified the oxygen content question it would be found in Greg’s “New Brewing Lager Beers“…
best of luck,
Scott

Recently got an email from a reader, with a recipe request.

I noted that you had an article on Belgian beers and thought I would write to you on the off chance you could direct me to a beer recipe. I was a Peace Corps Volunteer in Zaire from 1981-83 in the Bandundu region. The preferred beer by my crowd was Primus. I always assumed it was brewed based on a Belgian or German beer adapted to the conditions of Africa but but never knew for sure. I do know that it provided me and my fellow PCVs with many hours of enjoyment when we would come in from the bush every 3 months or so. Now that I brew my own beer I would love to locate someone with a recipe for Primus so that I could work on perfecting it in time for a reunion that we are hoping to hold in the next year or so. Any ideas on where I might find someone with a recipe?
-David

HI David – what little info I could find out indicates that Primus is brewed by Heineken-owned breweries in the Congo, the DRC, Rwanda and Burundi – looks to be pretty much a standard Dutch/Belgian lager (in the tradition of Heineken, Stella Artois, etc.) light gold in color, 5% abv… I can find no one that has a recipe on line, and I highly doubt it is imported into the US (if it were and if I could get a taste, I could come up with an approximate recipe….) – I think your best bet will be to track down a recipe for Stella Artois or Heineken and start there – if you have time to brew it a couple of times you might play with the hops from batch to batch, use a little maize or rice as an adjunct to lighten it some… White Labs has just introduced a yeast strain called “Belgian Lager” which would probably give you a really good approximation of what they are using in western and central African breweries… Let me know if you can’t find a starting place among the Dutch an Belgian lager recipes, I may be able to help there. Good luck!
-Scott

Thanks for the great advice. I’ll begin with something along the lines of Stella with some maize or rice and see where it takes me, I’m sure the brewshop I use up in Columbia, MD will be able to get me the Belgian lager yeast. I’ll let you know how it turns out. Primus wasn’t the best beer in Zaire, that accolade probably went to Simba or Tembo brewed out in Kasai/Shaba area, but the memories it helped create certainly rivaled anything else brewed on the continent
Feel free to use the question for your on-line article and include my email. In the strange world of brewers I suspect there has to be at least one other person out there who has had a longing for Primus.
Again, thanks for helping head me in the right direction, or at least a direction. David

SO, readers, any insights out there? Anyone else want to take a shot at a recipe for this obscure African brew?

Got an email from a reader and would like to address it publicly here. Brandon writes:
“I have read (Greg) Noonan’s book on Scottish ales, but I am not clear on the procedure for caramelizing the wort. I thought you might be able to answer some of my questions.
In the book, he says to lightly caramelize some of the wort. How much wort did he typically use? I have read of homebrewers boiling a gallon of first runnings and reducing it to a quart. Is this too much caramelization or is this similar to what Noonan did?
I have also read that longer boil times do not necessarily increase caramelization but instead increase Maillard reactions, which are two different things. So when making a Scottish ale, am I going for caramelization or Maillard reactions?
Any information you could offer would be greatly appreciated.”

Good question, Brandon – and potentially confusing! As I understand it, Maillard reactions do in fact produce pretty much the same results as caramelization, but due to amino acids rather than actual “burning” of the sugars. Maple syrup, bread crusts, milk caramels, etc. are darkened by Maillard reactions, true sugar caramel and the like are by “pyrolisis”, or burning. In terms of a Scotch Ale, I think we’d be hard pressed to differentiate – true caramelization should be easy to do, although if a Maillard reaction occurred we might not know the difference among all the other complex flavors in the brew…
What I usually do (and I have a recipe, inspired by Greg Noonan’s work, that comes awfully close to a Traquair House clone) is take the first 2 or 3 quarts of runoff (from a 5-gallon all-grain mash with a target OG of around 1080 at least) and boil it in a cast iron pot until it thickens to a syrup-consistency, and almost burns… takes some watching, especially if you are also still monitoring the runoff and sparging the rest of the mash… I will then dilute the caramelized wort with a few cups of ordinary wort and add it into the brew kettle….

I would love to hear from readers with more of a chemistry background, explaining, in layman’s terms, the difference between these two processes, and between their results…