Before I start, be warned that nothing in this post should be misconstrued as science. There are numerous flaws with the methodology. Variables are unaccounted for, errors were made, and measurements were imprecise; however, like all real science, it was fun and I got some pretty pictures out of it.

I’ve talked with several people on homebrewtalk, reddit, etc. in the past year about making a pale stout (or white stout) and the appropriate ways to add coffee to a beer. Generally, people recommend whole bean, cracked bean, or adding cold brew. I decided to test these three approaches to see what would happen. I didn’t want to ruin good beer, so fortunately, I discovered some cans of coors lite that had been sitting at room temperature for the past year to use as my base beer. Given how light in color the beer is, it was great for the color portion of the experiment.

I grabbed a few pint glasses and measured 6 oz of beer for each glass, then I calculated out how much various amounts of coffee would be if I was to scale it up to 5 gallons instead of 6 oz. It works out that about 4.25 grams of coffee beans in 6 oz of beer is about the same as 1 lb of beans in 5 gallons of beer (6 oz (beer)/(5 gallons * 128 oz (beer)) * 16 oz (coffee) * 28.35 grams per oz). My scale is not very precise (and fails miserably at trying to measure 1 gram), so I did 2 grams and 4 grams for each of the 3 types of addition. The whole bean and the cracked bean worked out well and I somewhat screwed up the cold brew, because I really had no clue how much water to add to the grounds. For the cold brew, I set my coffee grinder on the coarsest setting. If I were to do this in the future I think I would just do normal strength cold brew and then just add varying amounts of the cold brew. The coffee beans were a light-medium roast.

I used the flat side of a meat tenderizer to poorly crack some coffee beans. The top picture is 2 grams, the bottom is 4 grams.

The first picture after adding the beans. On a side note, I wrote “Crushed” on the labels, but in reality, the beans are cracked.

These two pictures are the beers after 4 hours. I’ve added a control beer that is just straight coors lite; however, it is cold and still fully carbonated, unlike the beers that have been sitting out for 4 hours with coffee in them. For reference, from left to right is 4 grams whole, 4 grams cracked, 2 grams whole, 2 grams cracked, and the control beer. As you can see, the 4 grams cracked has definitely changed colors and the 2 grams cracked is slightly darker than the whole beans and control. 4 grams cracked definitely had the most intense aroma. 2 grams cracked and 4 grams whole were approximately the same. 2 grams whole was barely perceptible over the Coors Lite smell.

The next set of pictures is after 8 hours. The whole bean has barely deviated in color from the control whereas both the cracked versions are noticeably darker. 4 grams cracked kind of smelled like smoky dive bar (likely because of the smell of stale coors lite). 2 grams cracked and 4 grams whole had similar intensity, but I got a little smell I can best describe as astringency from 2 grams cracked. 2 grams whole was still barely perceptible over the coors lite smell.

The final set of pictures now includes the cold brew coffee that was added. These took place at 22 hours. As you can tell the cold brews (beers #3 and #6 starting from the left side) have more liquid than the rest because I added the cold brew directly into 6 ounces. They are also hazy because of the sediment in the cold brew.

The aromas were pretty much the same at 22 hours. 2 grams cracked smelled more like a smoky bar. The cold press smells less strongly than the rest. Whole bean was definitely smoothest smelling throughout the entire experiment.

I’ve included some side by side comparisons. These took place at 27 hours.

Finally, I leave you with this —

Coors lite does not improve when you let it sit at room temperature for a year then open it and leave it in pint glasses for a day, even if you do add coffee. Tasting the samples was a horrible mistake, even if it was for science.