Equipment
Laboratory measurement versus practical measurement
Which measurements can I do myself and which need a laboratory?
In short
The distinction is not really about difficulty. It is about whether the measurement has a legal or safety consequence, and about whether the method available at home is specific enough to be trusted.
A hydrometer, a thermometer, a calibrated pH meter and a titration kit answer nearly every question a maker needs answered to make good cider.
Anything that will be printed on a label, declared to a revenue authority, or used to decide that a product is safe belongs with an accredited laboratory using a reference method.
What the bench can do honestly
The alcohol row is the one that trips people most often. Gravity arithmetic gives an estimate that is generally close enough to know whether a cider is around five per cent or around nine, and it is not a measurement in the sense a label requires. Reference determination is by distillation and density, or by an instrumental method, in a laboratory that can demonstrate its accuracy. Where a figure is declared, tolerances are set in law and the producer is accountable for them.
| Measurement | Practical method | Good enough for | Needs a laboratory when |
|---|---|---|---|
| Specific gravity | Hydrometer and trial jar | Tracking fermentation, estimating alcohol, deciding when to rack or bottle | A declared alcohol figure is required |
| Soluble solids in juice | Refractometer | Ripeness, lot selection, juice blending | A sugar profile is needed |
| Temperature | Probe or thermowell | Everything | Never, if the probe is checked |
| pH | Calibrated meter with two-point calibration | Sulphite decisions, spoilage risk, acid adjustment | A dispute or a specification demands a certified result |
| Total acidity | Titration to a pH 8.2 endpoint | Blending and acid adjustment | A specification or export requirement applies |
| Free and total sulphur dioxide | Ripper titration, with reservations | A rough relative indication only | Almost always — declarations and limits need aeration-oxidation or an equivalent |
| Alcohol by volume | Gravity arithmetic | A working estimate | Any label, duty return or legal statement |
| Patulin | None available | Nothing | Always — this is a food safety limit |
| Microbiological counts | A microscope tells you very little without training | Spotting gross problems | Any decision that depends on the count |
Getting more out of modest equipment
Precision and accuracy are different things, and a bench instrument can be usefully precise even when it is not accurate. A hydrometer that reads consistently two points high is perfectly good for measuring the change in gravity, which is what fermentation monitoring needs. What it cannot do is give an absolute number to compare with someone else’s.
That suggests the discipline that makes a small operation’s data worth having: use the same instrument, the same method, the same temperature and the same person, and record everything with a date. A run of internally consistent readings over three seasons is genuinely informative about a cider house. A scatter of readings from different instruments and different methods is not.
Sending occasional samples to a laboratory is what anchors that internal scale to the outside world. A single panel of analyses on a finished cider each year tells a producer how far their bench numbers sit from reference values and in which direction, which makes every bench reading afterwards more useful.
The measurements nobody should improvise
Patulin is a mycotoxin produced by moulds on damaged fruit, chiefly Penicillium expansum, and it is subject to regulatory limits in apple products. It cannot be tasted, cannot be smelled, and cannot be measured without chromatography. The control is not measurement but process: keeping rotten fruit out of the mill, since the toxin is concentrated in and around the rot.
Methanol is present naturally in cider at low levels from pectin breakdown, and is not a hazard in fermented cider at the levels involved. It becomes a real hazard in distillation, which is a different activity with its own licensing regime, and no measurement made in a cider house has anything useful to say about it.
Microbiological identification matters when a spoilage problem needs a name. Plating, microscopy and molecular identification are laboratory work, and a producer with a recurring fault is better served by one professional identification than by a season of guessing.
Numbers on labels
Also answered on this page
Questions this page covers, so you can tell at a glance whether it is the one you want.
- Do I need a cider laboratory?
- How do I know the alcohol content of my cider?
- Can I test for patulin at home?
Related
What people ask next
Questions readers ask about the things this page mentions. Each one goes to the section that answers it rather than to a page written to receive the question.
- Do i need a ph meter for cider, and how do i keep it accurate — A pH meter consists of a glass electrode that develops a small voltage proportional to hydrogen ion activity, a reference electrode, and a meter that converts that voltage into a pH reading.
- How do i know when my cider has finished fermenting — Take two hydrometer readings several days apart: if the gravity has not moved, the ferment is over. Airlock activity is not a reliable test, because a slow ferment can produce gas too slowly to see.
- How do i use a hydrometer to measure cider — A hydrometer floats at a depth determined by the density of the liquid it is in. Sugary juice is denser than water, so the hydrometer floats high; as fermentation converts sugar to alcohol the density falls and it sinks.
- How long does cider take to ferment — A warm ferment with cultured yeast can finish in one to two weeks; a cool wild ferment in a cellar may take three months or more. Slow is not the same as stuck — the test is whether gravity is still falling.
- How many calories are in cider — Roughly 40 to 60 kcal per 100 ml for most ciders, so a UK pint falls somewhere around 200 to 250 kcal. Alcohol contributes about 7 kcal per gram and residual sugar about 4, so both strength and sweetness matter.
- How do cider makers keep patulin out — By sorting rotten fruit out before milling, because patulin comes from moulds growing on damaged apples. Fermentation reduces what gets through, so fermented cider carries no limit where juice does.
Sources
What this page rests on. Where a source is marked as registered rather than read, CiderHQ is recording that the body is authoritative on the subject without claiming to have worked through the document itself. See our evidence policy for what each state means.
Cider and perry production technical training material
Peter Mitchell / Cider and Perry Academy · reference work · registered as competent for this subject
Searched again on 2026-08-25 and it remains the one printed source here that a bibliographic check cannot fix, because it is not a published work with an edition. It is course material issued to participants of a training programme, so there is no catalogue record to verify, no ISBN, and no lawful public copy. Its state stays `registered` for that reason rather than through inattention.
The Science of Cidermaking and associated technical writing
Andrew Lea · reference work · passage verified 2026-08-24
Written by a food chemist who worked at Long Ashton on apple phenolics. Unusual among specialist cider writing in that it is primary-research-adjacent: the author is describing work he did, and cites the literature. This is why it is registered at tier 1 for chemistry while a general cider book is not.
National Association of Cider Makers
NACM · specialist organisation · retrieved 2026-08-24
The UK trade association. Useful for industry-agreed definitions and for the voluntary labelling standards its members work to. A trade body has an interest in how its product is described, so CiderHQ cites it for what the industry says about itself rather than for neutral scientific claims.
Where to go next
- Cider making equipment — The rest of the equipment material, grouped by what each piece is for.
- How cider is made — The methods this equipment exists to carry out.
- Troubleshooting — The faults that are traced back to equipment and to cleaning.