Brew Batch 5: M-80 IPA – July 26, 2018

This batch was selected from as an all-grain recipe kit. It was a a value selection as the kit was priced at only $29. And of course. my favorite, an IPA.

I have added a few items to my brewing equipment since the last batch.

  • 100,000 BTU burner. The old setup was maybe 15,000 BTU. This should reduce the time to bring water and wort to boil.
  • Reverse flow wort chiller and pump. This should greatly speed up the boil cool-down.
  • 2 Liter Erlenmeyer Flask for yeast starter. Formerly using a 1 liter flask

Yeast Starter

A two liter yeast starter was prepared using American Pale yeast and DME. Perhaps a bit two much starter was added to the flask as it spilled over the first night on the spin plate.

Milling the Grain

The recipe specified 12 lbs of American Pale Malt and 1.5 lbs of Crystal 15L

But since I use brew in a bag (BIAB), 3 extra lbs of Munich Malt (That is what I had extra on hand) were also used. The extra grain was intended to make up for the BIAB inefficiencies. Tony just acquired a new 2 roller mill, which was used to crack the whole grains. It was set on the tightest opening (0.025 inches) with only 1 pass needed to get a decently opened grain texture.


About 6 gallons of water was initially heated to 170F for the Mash strike temperature (no temperature was specified in the recipe. The 15 gallon kettle flame was then turned off with the grain blend transferred to the mash bag and dropped into the kettle. It was stirred every 5 or 10 minutes during the 60 minute boil. Since an insulated mash tun was not used, the temperature dropped during the mash. With about 20 minutes remaining, the temperature read 148F. At that time, two to three additional gallons of separately boiled water was added to the mash to bring the temperature back up.


After the mash hour, sparging, consisting of gravity transfer of about 4 gallons from the kettle to a smaller, 5 gallon kettle and slowly pouring it over the grain bag. This was done 4 times and took about 25 minutes to complete. After the sparge, the grain bag was squeezed to extract as much of the wort as possible before removing it from the kettle. Yikes, very hot! There were 8 gallons of wort in the kettle at the start of the boil.


Flame on! Lighting the kettle again and cranking up the kettle with my new 100,000 BTU burner brought the wort to a boil in less than 15 minutes. The thermometer read 218F and had to be significantly reduced after a partial boil-over. Yet still the boil continued. The boil hop schedule:

  • 2 oz. Columbus hops for 60 minutes
  • 1 oz. Simcoe hops for 30 minutes
  • 2 oz. Columbus and 1 oz Simcoe hops for last 4 minutes of boil

Chilling the Wort

The reverse flow wort chilling hose worked great. The chilled wort was recirculated back to the kettle using a small pump. After about 25 minutes, the wort was down from 218F to about 80F. But that is when things slowed down significantly. The brew location was Ventura, California. What we found was that the garden hose water was not that cool, measuring 73F. This made it clear that we could not reach the 68F target yeast pitching temperature with this setup. After about 45 minutes, the wort was only 2F lower, to 78F. At this point, the wort was transferred to the fermenter and set to rest a while to cool down with the ambient air temperature (68 to 70F at the Ventura beach brewing location).

A sample of the wort was taken to measure the original gravity. OG measured 1.06. Target was specified in the range 1.058 – 1.062. OG was spot on the middle of the target range!

Pitching the yeast

The fermenter volume was measured to be 6.8 gallons. A two liter yeast starter was pitched at a temperature of about 73F.


Little action was observed after two days into fermentation. A closer look at the airlock revealed insufficient water present to float the lock. This was corrected with, hopefully, no contamination. After two days, four medium Valencia Oranges were added to the fermenter as called for in the recipe.

Dry Hopping

After 12 days, the wort was transferred to sanitary buckets so the fermenter could be cleared of trub and re-sanitized. The wort was then returned to the fermenter.

Final Gravity and ABV

At that time, the final gravity was measured to be 1.016. As result, the ABV is 5.8%. There was considerable pulp in the beer from the oranges, giving it a “hef” appearance. 

After a bit of research, I found that the added oranges during fermentation increase the FG reading:

from the article:

“The sugars from fruits will raise the specific gravity of your beer. For large additions of fruits, you may want to calculate how much the specific gravity will increase.

You can calculate how much a fruit addition will affect its specific gravity by using the following formula:

SG = [Wfruit X (Psugar/100) X 45]/Vbeer

In the equation, SG is the specific gravity increase due to fruits. It is given in “gravity points,” or the decimal portion of a specific gravity number. Wfruit is the weight of the fruit in pounds. Psugar is the percentage of sugar in the fruit. The number 45 is the extract potential — in gravity points per pound per gallon — of simple sugars (such as fructose, glucose and sucrose). Vbeer is the volume of beer in gallons. For example, if you use 10 pounds of cherries in your five-gallon batch of cherry wheat, you would calculate the specific gravity addition like this: SG = [10 (14/100) 45]/5 = 12.6, or about 13 gravity points. If your wheat beer weighed in at 1.048 before the cherries were added, it would now have a specific gravity of 1.061.”

So the actual ABV is higher than the calculated 5.8%. The expected value is 6.5%, so this beer might actually be closer to the expected value. 

Final Gravity and ABV Adjustment

Having said that, after doing a bit of research, here is my assessment of the impact of the added oranges on the FG and calculated ABV value…

From the above formula, you need to know how much the oranges weighed and the percent sugar in the oranges. And since we extract the oranges after fermentation, the weight is just the weight of the pulp. So it is very subjective.
Here is my rough estimate:
SG = [Wfruit X (Psugar/100) X 45]/Vbeer
Wfruit = 4 ounce(pulp) = .25 lbs
Psugar = 0.678
Vbeer  = 6.5 gallons
SG     = ( (0.25 * 0.678) * 45)/6.5 = 1.17
FG     = 1.016
FGadj  = 1.016 – 0.00117 = 1.014
ABV    = 5.8%
ABVadj = 6.0%  (IF  4 oz pulp in 6.5 gallons)
ABVadj = 6.2%  (IF  8 oz pulp in 6.5 gallons)
ABVadj = 6.4%  (IF 12 oz pulp in 6.5 gallons)
ABVadj = 6.6%  (IF 16 oz pulp in 6.5 gallons)
From wikipedia:
“One medium-sized navel orange contains 17.56 grams of total carbohydrates, which includes 11.9 grams of natural sugar.”
Psugar = 11.9/17.56 * 100 = 67.8%
If the beer is filtered, the filter weight could be measured before & after to get an idea of what the pulp weighed.
My guess is that we are in the range 4 – 8 oz. (ABV 6.0 – 6.2 %)

Post Fermentation Beer Assessment

After measuring the FG, the sample used was taste tested. It had a tangy orange taste. Dry, bitter finish. After tang on tongue. This is pre-dry hop.

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