PlinyTheMiddleAged
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Warning! Long post follows!
If you haven't seen the LoDO (Low Dissolved Oxygen) thread over in the Brewing Science forum, it is an entertaining read full of some interesting ideas and a bit of drama. Basically, the folks that started that thread advocate the use of practices that limit oxidation of the wort during the mash and boil steps and on through kegging. They are mainly doing so to get a malt flavor in their German-centric beers that is missing in more "traditional" home brewed beers. I brew mainly IPAs, but I thought I'd give the process a try to see if it improves my beers.
I brewed a beer similar to the Focal Banger clone recipe from a recent BYO article on NE IPAs. I use distilled water and Bru'n Water to help set my mineral content and pH. I shoot for a pH of 5.4 for my IPAs and I've settled on about 75:150 sulfate to chloride for NE IPAs. I usually get 75% kettle efficiency pretty easily.
That's the general background. Below I'll describe what I did in an attempt to implement a LoDO process. I will say up front that none of this was difficult, and I did see differences in the wort going in to the fermenter.
Step 1) Pre-boiled the strike water; added salts from Bru'n Water, and added sodium metabisulfite (NaMBS). NaMBS is the magic ingredient that limits oxidation. Pre-boiling reduces the amount of dissolved oxygen in the strike water. I added 50 ppm NaMBS based on strike water volume.
Step 2) I conditioned the grain and milled it directly into my bag. I ran a hose to the bottom of the grain bucket which was holding the bag and trickled in CO2 in an attempt to minimize oxidation of the cracked grains. I'm not sure how much this helped, but it was talked about in the main LoDO thread so I gave it a try.
Step 3) I chilled the strike water down from boiling to strike temp (using a stainless steel IC - copper is frowned upon by the LoDO folks) and mashed in. Mashing in was basically slowly lowering the bag of milled grains into the strike water so dough balls wouldn't form. I then added a mash cap - I just floated a large piece of tin foil on top of the mash. I slapped a lid on the kettle, and wrapped it in sleeping bags for an hour.
Step 4) Pulled the bag and minimized splashing/dripping back into the kettle - I let the bottom inch or so touch the top of the wort while the bag drained. Then brought the wort to a gentle boil for an hour.
Step 5) Cooled using a stainless steel IC.
My observations:
The LoDO wort was definitely different than usual - there was almost no smell at all. There was a very faint musty smell - probably from sulfur compounds.
The wort was very pale and clear. I'm used to having really cloudy wort in the samples I pull for pH checks. The sample I pulled was like tinted glass.
And speaking of pH, Bru'n Water always serves me well getting me pretty close to my desired target. With the addition of NaMBS, I hit 5.25 (shooting for 5.4). I've never been that far off before, so maybe this is caused by NaMBS?
Hot break was different - very "fluffy", like snow. Maybe since the wort was more clear, I could see it better during the boil and that's why I thought it looked different. Maybe it was different.
Hops smelled different - I think this might be because there was almost no grain smell, but the hops really smelled bright and fresh.
Finally, the wort going into the conical looked pretty clear and light - not sure it was more clear than "normal" wort. However, efficiency took a hit. I ended up at around 65% when I usually see close to 75%. Perhaps this was from the lower pH? Maybe not. It's hard to tell from a sample of one.
All in all, the LoDO process was fairly simple - pre-boil the strike water, dose with 50 ppm NaMBS, add a mash cap, and boil gently. I'm not sure I'd go to the trouble of milling in a CO2 flushed bucket again (although it was easy). The only thing I had to buy was the NaMBS.
It's busy doing its thing in the conical - I'll report back as it progresses.
PlinyTheMiddleAged
If you haven't seen the LoDO (Low Dissolved Oxygen) thread over in the Brewing Science forum, it is an entertaining read full of some interesting ideas and a bit of drama. Basically, the folks that started that thread advocate the use of practices that limit oxidation of the wort during the mash and boil steps and on through kegging. They are mainly doing so to get a malt flavor in their German-centric beers that is missing in more "traditional" home brewed beers. I brew mainly IPAs, but I thought I'd give the process a try to see if it improves my beers.
I brewed a beer similar to the Focal Banger clone recipe from a recent BYO article on NE IPAs. I use distilled water and Bru'n Water to help set my mineral content and pH. I shoot for a pH of 5.4 for my IPAs and I've settled on about 75:150 sulfate to chloride for NE IPAs. I usually get 75% kettle efficiency pretty easily.
That's the general background. Below I'll describe what I did in an attempt to implement a LoDO process. I will say up front that none of this was difficult, and I did see differences in the wort going in to the fermenter.
Step 1) Pre-boiled the strike water; added salts from Bru'n Water, and added sodium metabisulfite (NaMBS). NaMBS is the magic ingredient that limits oxidation. Pre-boiling reduces the amount of dissolved oxygen in the strike water. I added 50 ppm NaMBS based on strike water volume.
Step 2) I conditioned the grain and milled it directly into my bag. I ran a hose to the bottom of the grain bucket which was holding the bag and trickled in CO2 in an attempt to minimize oxidation of the cracked grains. I'm not sure how much this helped, but it was talked about in the main LoDO thread so I gave it a try.
Step 3) I chilled the strike water down from boiling to strike temp (using a stainless steel IC - copper is frowned upon by the LoDO folks) and mashed in. Mashing in was basically slowly lowering the bag of milled grains into the strike water so dough balls wouldn't form. I then added a mash cap - I just floated a large piece of tin foil on top of the mash. I slapped a lid on the kettle, and wrapped it in sleeping bags for an hour.
Step 4) Pulled the bag and minimized splashing/dripping back into the kettle - I let the bottom inch or so touch the top of the wort while the bag drained. Then brought the wort to a gentle boil for an hour.
Step 5) Cooled using a stainless steel IC.
My observations:
The LoDO wort was definitely different than usual - there was almost no smell at all. There was a very faint musty smell - probably from sulfur compounds.
The wort was very pale and clear. I'm used to having really cloudy wort in the samples I pull for pH checks. The sample I pulled was like tinted glass.
And speaking of pH, Bru'n Water always serves me well getting me pretty close to my desired target. With the addition of NaMBS, I hit 5.25 (shooting for 5.4). I've never been that far off before, so maybe this is caused by NaMBS?
Hot break was different - very "fluffy", like snow. Maybe since the wort was more clear, I could see it better during the boil and that's why I thought it looked different. Maybe it was different.
Hops smelled different - I think this might be because there was almost no grain smell, but the hops really smelled bright and fresh.
Finally, the wort going into the conical looked pretty clear and light - not sure it was more clear than "normal" wort. However, efficiency took a hit. I ended up at around 65% when I usually see close to 75%. Perhaps this was from the lower pH? Maybe not. It's hard to tell from a sample of one.
All in all, the LoDO process was fairly simple - pre-boil the strike water, dose with 50 ppm NaMBS, add a mash cap, and boil gently. I'm not sure I'd go to the trouble of milling in a CO2 flushed bucket again (although it was easy). The only thing I had to buy was the NaMBS.
It's busy doing its thing in the conical - I'll report back as it progresses.
PlinyTheMiddleAged