HCA dosing bench

Batch and context

Volume

litres

Start date

Day 0

Context

Sampling cadence

weeks; 4 at 24–25 °C

Stock strength

HCA stocks

Targets or additions

Mode

4-EP

µg/L

4-EG

µg/L

4-EC

µg/L

Caffeic source

Capsule: ~110 mg chlorogenic acid, bound; esterase liberates it over weeks. Stock: free acid, 10 mg/mL.

Wort baseline and efficiency

p-Coumaric

mg/L, 1–3

Ferulic

mg/L, 2–8; the model treats it as free

Caffeic

mg/L, < 0.5

Ferulic rest

The rest lifts ferulic to 8–15 mg/L; the baseline field is set to 8 when chosen.

Efficiency, free acids: p-coumaric 50 % ferulic 45 % caffeic 40 % bound (chlorogenic) 4 %

50 % free / 3–5 % bound are the wiki's working figures (Med). The per-acid split is a working assumption (Low); the range shown uses ±10 points.

Per compound

Pathway	From baseline	Precursor to add	Stock	Expected product	Against targets

Schedule

Date	Event	p-Coumaric	Ferulic	Caffeic	Note

HCA stock

Compound

Concentration

40 fails to dissolve

Volume

5 mL batches preferred

Made

Storage

°C

Green coffee slurry

Capsules

Warm vodka

mL

Zinc

Vessel

litres

Dose

mg Zn/L, 0.1–0.2

Make-up

Weigh

–

mg, ±1 mg

Ethanol ~98 %

–

mL, dissolve first, ≤ 40 °C bath

Distilled water

–

mL, then swirl

1.0 mL delivers

–

mg

Use by

–

6 months at 4 °C

At the storage temperature

–

months, Q10 = 2 rule of thumb (Low)

50 % ethanol is deliberate: neat-ethanol stock shock-precipitates on dosing. Amber or foil-wrapped, fridge, never frozen, septum vial and syringe; never return a used syringe. Fresh stock is near-colourless pale yellow; deep yellow, brown or cloudy means remake.

Label

–

Green coffee and zinc

Chlorogenic per mL slurry

–

mg/mL

Half capsule

–

mL of slurry

Expected 4-EC per capsule

–

µg/L per 5 L, 3–5 %

Zinc dose

–

mg elemental Zn, once

Zinc stock volume

–

mL of 1 mg/mL

Zinc timing

–

single dose; repeats pointless, more inhibitory

Zinc stock: one 15 mg zinc sulfate tablet crushed into 15 mL boiled-cooled water gives 1 mg/mL; excipient sediment is expected, dose from the liquid. Slurry: refrigerate, use within weeks. Distinct bottle and cap colours for zinc and HCA stocks; the volumes and syringes are identical.

Largest single dose

Taken from the schedule on the Dose tab; override to test a bolus.

p-Coumaric

mg

Ferulic

mg

Caffeic

mg free acid

Substrate toxicity margin (Harris et al. 2015)

Acid	Dose	mg/L	mM	Lag at ~4 mM	MIC (lowest)	Margin

A 25 mg spike into 25 L is 1 mg/L ≈ 0.006 mM, three orders of magnitude below the growth lag and four below MIC. Toxicity is not a reason to micro-dose; flux matching, residence-time losses and overshoot control are (§12.2).

Airlock budget

Dosing events

–

in the schedule

At sampling points

–

co-located, no extra O₂

Extra openings

–

not on the cadence

Programme length

–

weeks, Day 0 to last dose

Stock use-by

–

6 months from make-up

Smallest dose

–

mg; floor 2 mg per 5 L

The 4–6 week sampling lift is already the calibrated oxygen dose. Dose events must sit on sampling events, never on top of them; the floor is about 4–6 doses across six months. A 10 mg/mL stock with a 1 mL syringe resolves ~0.5 mg, so below ~2 mg per 5 L measurement error dominates.