Analyzing 1,570 IPAs from Tree House, Trillium, Other Half and Monkish

Note: The raw data from December 14, 2020 can be downloaded here.

Rikunert and Koen Van den Heuvel both previously demonstrated there is a correlation between alcohol by volume (ABV) and average rating/score (on Untappd and/or BeerAdvocate). Curious to see if this was true for New England IPA (NEIPA), I transcribed every Tree House, Trillium, Other Half, and Monkish IPA on BeerAdvocate into Excel. After removing incomplete samples, I analyzed the remaining 1,570 IPAs using Excel:

%Combined
(1,570)
Tree House
(259)
Trillium
(224)
Other Half
(719)
Monkish
(368)
Mean8.047.768.098.018.28
Standard Deviation1.160.661.191.301.06
Mean – Standard Deviation6.897.106.906.717.22
Mean + Standard Deviation9.208.429.289.329.33
First Quartile (Q1)7.307.257.207.208.00
Second Quartile (Q2)8.107.908.008.008.30
Third Quartile (Q3)8.508.208.608.508.60
Fourth Quartile (Q4)13.009.8013.0013.0012.00
Interquartile Range (IQR)1.200.951.401.300.60
Lower Limit5.505.835.105.257.10
Upper Limit10.309.6310.7010.459.50
Lowest3.304.103.304.005.00
Highest13.009.8013.0013.0012.00

Using the combined data set, I calculated the normal distribution and graphed the data (see the figure above). Note:

  • Solid blue line = normal distribution of ABV %
  • Solid dark green line = mean
  • Dashed dark green lines = standard deviations
  • Solid red lines = lower/upper range limit
  • Solid red area = outliers
  • Dashed light green lines = Brewers Association (BA) Style Guideline ABV % for Juicy/Hazy India Pale Ale and Juicy/Hazy Imperial/Double India Pale Ale
  • Solid light green lines = mean for beers within Brewers Association Style Guidelines

Furthermore, I fitted the data sets to a linear regression analysis and calculated the coefficient of determination (R2) to determine how closely the model fits the data. The R2 results were:

  • Combined = 0.0718
  • Tree House= 0.0047
  • Trillium = 0.00007
  • Other Half = 0.0005
  • Monish = 0.0004

Based on the low R2 values, there is a very weak correlation between ABV and average rating/score for these 1,570 IPAs. In other words, higher NEIPA ABV does not produce higher rating/scores.

But the analyses above do suggest a good target for NEIPA ABV is between 6.89 and 9.20%. This range includes the overall mean (8.04%), BA NEIPA mean (6.94%) and BA NEDIPA mean (8.57%) and is bound by one standard deviation above and below the overall mean.

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