January 22, 2011

Brewing of an Oud Bruin Part 4 -- Completing the Pale Ale

This is a little delayed because I have been caught up with trying to get in gear for the new semester and some other stuff around the house but the pale ale portion is complete and working away.

The final recipe was fairly straightforward:

1 gallon
5.88 ABV
4.2 SRM
33 IBU
1.061 OG
Est. FG 1.016

2 lbs. pilsner
4 oz. carahell

Mash schedule:
Mashed half once for an hour at 150 and sour mashed for two days with grains for lactobacillus growth
Mashed other half at 155 for an hour

Combined two mashes together and boiled for 90 minutes

Hop additions:
.40 oz Fuggles at 90 min.

Post-boil additions:
1 oz oak chips (repeatedly boiled and left to soak in water for over a month)
Stepped up culture of Brett B from orval dregs
1 tbsp white vinegar

The recipe is basically the same as I posted before. I dropped the hops a little. I added some oak, partially for flavor but mostly as an additional source of sugar for the brett and to use as a source to transfer bugs to a future batch. You may also note that I added one tablespoon of white vinegar. I did this for two reasons: one it would help lower the pH and encourage brett fermentation; and two as a slight flavor addition for complexity.

Although I aerated the wort before pitching, I still experienced a delay in seeing signs of fermentation. It took about a day for fermentation to start up. Although some people say brett fermentations are very explosive, I find that mine was not. I'm not sure whether I ended up getting a lot of fermentation from the saccharomyces in the Orval culture or what but the fermentation looked fairly similar to a saccharomyces fermentation. Krausen fell after about five days. A week later the beer is very turbid for having finished fermentation, which leads me to believe that there is still a lot of activity going on in there. So far, there is no pellicle or unusual activity beyond the turbidity, but since there is probably a lot of CO2 sitting on the beer it is unlikely that a pellicle would form. Nonetheless, I plan on keeping the beer in the fermenter for at minimum three months but depending on how it looks (and possibly tastes) I may leave it for up to six months.
January 14, 2011

Brewing of an Oud Bruin Part 3 -- So It Begins

Making the Starter

A week and a half ago I added a small amount of Orval dregs to a small amount of starter wort as is normally the case when one bottle harvests yeast. I waited...and waited. Nothing. A few days in I realized that brett usually functions in an acidic environment and I needed to drive down the acidity to give it a hand. The only food grade acid I have in the house is vinegar, which contains small amounts of acerbic acid. Then I waited some more. Nothing. I added yeast nutrient and yeast energizer in small quantities each day. Nothing. Then I added some more vinegar. The only thing I could get to grow were strange white blobs on the sides of the flask where my aeration-swirling had left grain bits and residue on the walls. Very disheartening.

God may have rested on the seventh day but brett decided to start working on the seventh day. I came home from school to find the starter full of saccharomyces-like krausen. It smelled fruity, somewhere in between a saison yeast and a Belgian abbey strain. It was a start, for sure. After several days the krausen died down. I decanted the liquid and added more wort. This was followed by about a day of inactivity before a new krausen formed. This krausen was different. It was filmy and full of balloon-like bubbles. The smell is best described as musty dates. Sounds gross, I imagine, but it actually smells quite good.

Looking in the bottom of the flask, I have a very thick layer of yeast. I hope most of that is brett, rather than sacc. The only thing that half-concerns me is that the white spots seemed to have moved over to the top of the pellicle-like krausen. I suspect it is lacto or brett being funky. It reminds me a lot of what got into the cherry beer I made last year. I'm only half concerned because getting some lacto in an oud bruin is more a positive than a negative since oud bruins are typically dosed with both lacto and brett.

Sour Mashing

I decided to sour mash half of the total pale ale volume. The reason I chose to do so much is because the brett starter would only function in a very acidic environment and that is exactly what the sour mash creates. I would rather the pale ale come out way too sour and make the brown ale sweeter than risk brett being a secondary player. I want the brett to take hold before saccharomyces can.

I sour mashed the half gallon in a half gallon growler with some foil over the lid. Ultimately that will make the sour mash slightly less than half because I will need to compensate for boil off in the other half, but it's close enough. I forgot how much of a pain in the ass sour mashing can be. Brewers don't normally mash in glass because it has zero insulation so you lose heat very quickly. During the day I have had to keep it in a sink and add small amounts of boiling water to keep the temperature up so the bacteria will work quickly. I don't have a heating blanket or an aquarium heater; both would make it a lot easier. Without heat, who knows what bacteria would take hold and what kinds of nonsense it could do.

The strain of lacto generally found on plants is L. brevis, which is like the badass of lacto strains. It is hop resistant, it doesn't fear alcohol and it is heterofermative so it can ferment both aerobically and anaerobically. I believe (and I may be remembering incorrectly) when it ferments anaerobically it produces a small amount of ethanol. Since this is the strain generally found on plants it is also the strain that normally makes its way into sour mashes by way of the grain. Commercial versions of lacto are typically L. delbruckii, which is a more gentle strain that is homofermative (so it only ferments aerobically) that tends to produce more desired flavors in beer. I haven't seen my sour mashes form a pellicle, which is often the hallmark of L.debruckii. Instead, the sour mash gets foamy and pushes out a thick brown goop. Rather than tart it smells very much like creamed corn, which is probably a sign of DMS. The brown goop is like krausen but without any bubbles.

I will most likely let the sour mash go two days, possibly three. I really want to get this as sour as realistically possible without it tasting like total piss. Once the sour mash is done I will mash the other half, add the sour mash to the boil kettle and finish it all up. I will post that section as soon as the sour mash is complete.
January 8, 2011

Lambic Solera Update #1

The lambic is a few days shy of being a month old. It fermented predictably normal the first couple of weeks. Krausen, airlock bubbling, etc. It has slightly cleared up in the way you would expect a month old wheat beer to be. At this time there is no pellicle; I was not expecting any signs of one yet but I am keeping my eye out. I did remove the cap on the carboy and took a couple of whiffs. It is clear that the bugs are souring away. It has a very tart aroma to it, much like the Lindeman's gueuze -- which is no surprise since I added dregs from a bottle of it -- but it still has some sweetness to the smell like a normal beer.

Nothing too exciting to report yet but hopefully in a few months I will get some pellicle formation and I'll have some good pictures to show.