Cold Brew experiment results.

brew.md

Cold brew

Initial test on 10/17/16. Grounds were 20 days old, all Stumptown Hair Bender.

Ratio	Water	Grounds	Ground Size	Extraction Time	Quality
5/1	500ml	100	21	15:15	A
10/1	500ml	50	21	15:15	B
15/1	500ml	33.3	21	15:15	D

Test #2

10/18/16. Grounds were 21 days old, all Stumptown Hair Bender.

Ratio	Water	Grounds	Ground Size	Extraction Time	Quality
5/1	1000ml	200g	21	16:30	A

Test #3

10/20/16. Grounds were 33 days old, all generic Winco beans. This test is to demonstrate starting temp differences. Next attempt will use boiling water to start, and freezing water.

Ratio	Water	Grounds	Ground Size	Steep Time	Quality	Water Temperature (F)
5/1	250ml	50g	21	24	C	120
5/1	250ml	50g	21	24	C	70

edit:
result there was no noticeable difference in flavor for tap water temperatures.

for boiling vs. freezing-temp water, the boiling water was far more acidic

The quality is rated fairly low as I used flavored beans (chocolate and macadamia nut, if I remember correctly) which didn't lend itself well.

Test #4

7/20/17 - let the experimenting re(begin)! Used the two kitchen French presses for this. Going to suss out the effect steeping time and water temp have on this. Note that I went for a little less coffee grounds than the 5/1 ratio.

Ratio	Water	Grounds	Ground Size	Initial Water Temp (F)	Steep Time	Cooling Time	Quality
8.35/1	~1420ml (48oz)	170g	30	176	~22hrs @ room temp	all weekend (48+ hrs)	A (my opinion)

@dylanschultz what was the take-away from your water temp test last Ocotober?

Ratio	Water	Grounds	Ground Size	Initial Water Temp (F)	Steep Time	Cooling Time	Quality
5/1	1000 ml	200 ml	21	176	14 hrs @ in fridge	redundant	B+

The purpose of this test variation is to find a methodology that will support the best balance of strength/taste but also allows me to start at the end of a work day and drink at beginning of following work day. I have carried over the 5/1 ratio and 21 grind size measurement from previous tests. I am hoping by starting at a hotter temp, as was done in test #4 but leaving the conditions from the highly rated test #2, I can achieve the desired balance. Volume measurements done using side of mason jar.

This test is the result of a failed test from yesterday (undocumented) that used less exact measurements and very cold water.

Update: Edited quality after taste test. Smooth, did not need to be cut flavor wise. I found it to be too strong though and needed to be diluted. This is what contributed to me not giving it an A. Also, took a long time to filter but that may just be how it goes.

@mikewilburn ooo I forgot about this. Edited in the results.

tl;dr the colder the better starting water temp imo

I had a plan for ratio's but the brewer ended up not having the room for it all. I'll set up a new batch over the weekend