Exp.3: “NEIPA – When to dry hop if using Vitality starter (Sound vs. Inferred detection?)

In the 3rd experiment I will try hold the sound Bubble Logger up against the inferred version. As stated a bit in “Theory behind the project” I have so far tested one sound sensor and 2 different inferred sensor (of same type), and hence, the sensors is ofcouse very important for this project to work. Sometime down the patch I will try test more sensors of both types, but it this brew I attached both the inferred and the sound sensors to see how the 2 working sensors compares to each other and how the code (99% is this same) play into this for one sensor being digital and the other analogue.

Fermenter with the 2 Bubble Loggers attached standing on heating plate.

Besides the “inferred vs. sound” testing, we also gonna look at the time of dry hopping a NEIPA (my favorite) as most recipes tells to dry hop at high kreuzen on day 3 to get most biotransfrimation. From my experience using vitality starter ( = high amounts of yeast cells) this is likely to late. But let us come to that when we look at the data!

Just for info I brew all my NEIPAs raw and just get it up till 80´C where I keep it for 30-60min hopstand, hence, I only add hosptand hops and one time dry hopping.

Recipe and data: https://share.brewfather.app/dLN1oUW2cRv9gW

(PIF = “put in pot” of various hops from freezer).
Specialty IPA – New England IPA

CheapFather (21L pot/max 22L fermet@ration 3L/kg)
58% efficiency ????
Batch Volume: 19.5 L
Boil Time: 0 min

Mash Water: 17.88 L
Sparge Water: 7.27 L @ 70 °C

Original Gravity: 1.052
Final Gravity: 1.010
IBU (Tinseth): 27
Color: 8.9 EBC 

Strike Temp — 70.8 °C
Temperature — 65 °C — 90 min
Mash Out — 72 °C — 20 min

Malts (5.725 kg)
2 kg (34.5%) — Thomas Fawcett Pale Malt, Golden Promise — Grain — 5.9 EBC
2 kg (34.5%) — Viking Malt Pilsner — Grain — 4.5 EBC
900 g (15.5%) — Avangard Wheat Malt — Grain — 3.9 EBC
825 g (14.2%) — Oats, Flaked — Grain — 2 EBC

Other (68 g)
117 g (1.2%) — Bottling Sugar Cubes — Sugar — 3.9 EBC — Bottling
1 g (0%) — Briess Rice Hulls — Adjunct — 0 EBC

Hops (468 g)
60 g (12 IBU) — Cascade 6.6% — Aroma — 30 min hopstand @ 87 °C
30 g (7 IBU) — Amarillo 7.6% — Aroma — 30 min hopstand @ 87 °C
20 g (8 IBU) — Ekuanot 13.6% — Aroma — 30 min hopstand @ 87 °C
131 g — Citra 12.7% — Dry Hop — 6 days
81 g — Ekuanot 15% — Dry Hop — 6 days
75 g — Azacca 15% — Dry Hop — 6 days
71 g — Amarillo 8.2% — Dry Hop — 6 days

Hopstand at 87 °C

10 g — Calcium Chloride (CaCl2) – 33% — Mash
2 g — Epsom Salt (MgSO4) — Mash
2 g — Gypsum (CaSO4) — Mash
4 ml — Lactic Acid 80% — Mash

0.7 pkg — Fermentis S-04 SafAle English Ale

Primary — 18 °C — 14 days

Carbonation: 2 CO2-vol

Water Profile
Ca+2  128 Mg+2  8 Na+ 8 Cl 196 SO4-2 76 HCO3 16


Besides test the Sound sensor (green line) vs. the inferred sensor (blue line) the scope of this test was to look a bit on the statement often fund in various NEIPA recipes regarding “when to dry hop”? Many recipes states to dry hop at high kreuzen at day 3, and if we look at the BPM figure 1, we see the high kreuzen is happening after 19-20 hours if having a high number of yeast cells as we ofcouse do when making a very virile Vitality starter .

Figure 1: Blops pr. min (BPM), Sound sensor vs. Inferred senor in a NEIPA starting out at 16´C.

In this brew we made use of 11.5 gram dry yeast vitality started over 24 hours in 1 Liter wort of 1030 (e.g. original wort with some water thereby reducing the OG till 1030). Hence, this is a simple starter and even in this case we see high kreuzen after 19-20 hours giving day 1.

If we look when day 3 happen there is not much activity left and question would be if we are in a prosuit of biotransformation of the hops, then in my mind, day 3 seems rather late. I chooses to dry hop day 2 after 48 hours and at the time the hydrometer showed 1.012 and that might even also be to late for a real biotrasnormation.

The other part of the experiment shows that the Sound sensor and inferred sensor follows each rather fine.

Figure 2: The “Sum BPM/L” over time. After 4-5 day of brewing the increase in BPM is getting low ~indcating the fermentation is comming to the end.

From Figure 2, we can see the expentional increase is flatten after 4-5 days and after 9 days it is time for me to consider bottling. I let it cool crash over night before bottling just to settle a a bit of yeast, but I do bottle very fast for my NEIPAs to avoid any oxygen. I also bottle directly from tank and use sugar cubes in bottles to limited any oxygen exposure.

Figure 3: Temperature.

The temperature curve, Figure 3, shows the 2 loggers are showing the same temperature.

Last, but not least, then Figure 4 shows the SG over time. As the logger reports the rG (reduction in gravity) we can calculate the SG over time by subtract the OG with rG and hence get Ubidots to do this calculation.

Figure 4: The SG over time as calculated by OG – rG in ubidots as a function.

Putting the data into table-form we see there no big differency between sound vs. inferred detection, and both follow the gravity reduction:

Figure 5: Final data in regards of rG, SG and “Sum BPM/L

Hydrometer pictures:


Seen from my chair I can conclude the Bubble-Logger agian seem to work good, and the 2 verified sensors I got now, seem to predict the rG and hence SG rather good.

In regards of NEIPA and when to dry hop: If making normal starters or a 24 hours vitality starter one should really consider when high Kreuzen is happening, coz above data clearly states it happens way faster than day 3 witch many recipes states as time for dry hopping. So use common sense and observe your fermentation. In this light I find the Bubble-logger as being helpful and form the former time I used the Bubble-Logger for NEIPAs (Raw NEIPA) I come to the conclusion one maybe have to dry hop already day 1 or no later than day 2 (or even added in at the time of pitching if being a bit lazzy).

Last picture (how data looks in brewfather):

Figure 6: Data in Brewfather. Gravity line is above hydrometers reading entered manually.

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