“Dada, help me find my pink-pong ball!” my two-year-old son mispronounces his request between hacking coughs. He’s a mess; sick and miserable.

Meanwhile, my normally bubbly five-year-old is walking around with bags under her eyes that would make Jim Lehrer jealous. She’s exhausted, coughing, feverish, yet surprisingly delightful. She’s even interested in tasting the dust at the bottom of my specialty grain bag. Such a trooper.

So, I’m looking under furniture for a ping-pong ball while trying to get additional ingredients up from the basement. I’m stepping over a box filled with Matchbox cars and busted trucks while steeping grains in 150°F water for 30 minutes.

Later, I’m standing at the stove attending to a steaming pot. A pendulous and sagging grain bag dangles above the pot as I try to move it to the compost bin. Just then my son comes wheeling over and slams into the back of my legs, shouting, “let’s dooooo something.” Somehow the massive muslin manages to stay together and my son avoids the burn unit. As much as I’d love to play with my little man, the pot is approaching boil and I’ve got to get going on this brew. I only have a brief brewing window before I need to go to work this afternoon.

Lucky for me and this Black IPA, my wife is home today and swoops in just in time and, magically, gets the kids down for a nap and I quickly set to work.

Before I was nearly knocked over by my kid, I was tripped up slightly by the recipe, which calls for 7.5 lbs of extract. Since the LME I usually use comes in 3.3lb sizes, two canisters only give me 6.6 pounds. So I supplemented with a pound of Briess Golden Light DME.

Also, the recipe calls for yeast nutrient at fifteen minutes. “And yeast nutrient is …?” I asked Joe at Princeton Home Brew when I bought the stuff. He stared impassively and said, “diammonium phosphate.” And I burst into tears. Well, not really, but why is there always something more to learn? I’ve been brewing for nearly a decade and have never even heard of yeast nutrient, never mind the toxic chemical-sounding “diammonium phosphate.” Isn’t that the stuff an evil genius would use to try to kill a super hero? “I’ve suspended Batman over a vat of diammonium phosphate,” the Joker says in a bit burst of exposition. “I’ll lower him into it and it will eat away his flesh and Gotham will be rid of the Caped Crusader forever – HA! HA! HA!”

I googled it and the first hit I found read, “yeast nutrient gives nourishment to your yeast,” which is about as circular a definition as you’re going to find. Wikipedia was only slightly more helpful. According to the site, diammonium phosphate has numerous uses including as a “fire retardant” and a “nicotine enhancer in cigarettes,” and, of course as yeast nutrient. Clearly, I’m not getting any useful answers. I understand that the goal of including it in my beer is to create healthy yeast for an active fermentation but why do I need this chemical powder to do it? And why in this brew?

On a site about viticulture, I learn that yeast nutrient provides nitrogen for the yeast. This is necessary when making wine because grapes lack sufficient nitrogen, which encourages yeast reproduction.

So diammonium phosphate is like Barry White to yeast?

The real answer eludes me.

Having failed in my research, I moved the pot to the ice bath and hoped the temperature would drop precipitously. The children's naps were over faster than I could say “diammonium phosphate” and they were clamoring to get outside.  After several hours on ice, the temp was around 78-76°F. Not quite the 75°F recommended by the label on the San Diego Super Strain but I pitched anyway. These are the tough decision Dad-Brewers must make for their babies: beer and otherwise. Yeast pitched, I headed to the park a hopeful Dad with happy children.

Last modified on Monday, 11 February 2013