Ledger / Semi-hard / 2026-09-12
Raclette: A Hot Scald, a Brine Wash, and a Three-Month Window
Raclette melts because it was scalded to 42 C, which drives out enough moisture to make the paste hold together when it liquefies. Under-scalded raclette turns to oil on the machine. The rind wash is light and the aging short, and both of those are deliberate.
Each segment is as wide as its share of the 110 minutes in the vat; the set segment carries the set temperature, the cut segment carries the cut size.
Salt and press drawer
Press ladder
- 6 kg0.5 h
- 12 kg2.5 h
- 18 kg7 h
2-3% brine wiped over the surface every 2-3 days. Selects for Brevibacterium linens and the orange, oniony rind.
A mixed culture and a scald that actually scalds
0.5% mixed mesophilic and thermophilic culture at 33 C, thirty-five minutes of ripening, 24 IMCU of animal rennet per litre, thirty-five minute set. Cut to 10 mm and raise to 42 C over thirty-five minutes.
Forty-two degrees is not negotiable. It is what gives raclette its 40% moisture and its ability to melt into a sheet rather than a puddle. A 38 C scald tastes fine raw and behaves badly on the machine.
Press hard, then brine at 22%
Press at 6 kg for thirty minutes, 12 kg for two and a half hours, 18 kg for seven hours. Then brine at 22% and 12 C for five hours per kilo, so a 4 kg wheel gets twenty hours.
Twenty-two percent is strong and the time is long, because raclette is salted for its melting behaviour, not only for flavour. Under-salted raclette separates into fat and protein when it melts.
Wash with 3% brine once a week, for four weeks
Dry at 14 C for two days, then age at 12 C and 90% RH. Wipe with 3% brine once a week for the first four weeks, then stop. The rind should end up a damp, even orange-brown, not thick.
Raclette rinds are thin by design. If you keep washing past four weeks the rind firms into a shell, and a shelled raclette will not melt evenly at the edge.
Three months, and the half-wheel trick
Age three months at 12 C, turning twice a week. At three months the paste is supple and the flavour is mild and milky with a slight nuttiness. At five months it is firmer and sharper, which is fine to eat but no longer melts as well.
Cut the wheel in half and keep one half wrapped at 6 C for eating raw. Half a raclette eaten as a table cheese is one of the better arguments for making your own: the raw version is sweeter and more herbal than the melted one, and it never appears in shops.
Aging parameters
| Milk | Raw cow milk 3.9% fat |
|---|---|
| Culture | Mixed meso/thermo 30–42 °C |
| Rennet | Calf rennet (animal) 24 IMCU/L |
| pH at drain | 6.4 target 6.1–6.5 |
| Target moisture | 40 % |
| Cave temperature | 12 °C |
| Cave humidity | 90 % |
| Aging days | 90 days |
| Rind treatment | Brine wash |
| Yield | 4.0 kg |
Raw cow milk Semi-hard 90 days
Defect diagnosis
Flagged on this make: Bitterness、Misread surface mould
Bitterness seen this make
Signal — A harsh, lingering bitter note at the back of the palate, strongest in the first three weeks and often fading after six.
Cause — Too much rennet for the set time, or a microbial coagulant with high protease activity, or a scald that never got past 38 C.
Fix — Cut the dose by 20% next make and hold the scald 2 C higher for 10 minutes longer. Bitter peptides are water-soluble, so a 12% brine for 24 hours pulls some out.
Rancidity not seen
Signal — Soapy, paint-like smell that hits before the cheese reaches the mouth. Sharp and unpleasant rather than merely strong.
Cause — Free fatty acids released by lipase, usually from raw milk that sat warm too long, or from rennet paste, or from a knife or cloth that carried old milk residue.
Fix — Chill milk to 4 C within two hours of milking and pasteurise anything older than 24 hours. Retire the cloth: boil it, do not just rinse it.
Faulty eye formation not seen
Signal — Either no eyes where the style demands them, or a scatter of irregular slits and cracks instead of round, evenly spaced holes.
Cause — Coliform or yeast contamination from unsanitary brine, or a press that was too cold (below 18 C) so the propionic culture never woke up, or too much salt killing it outright.
Fix — Boil and re-salt the brine to 18-20% between batches, press at 20-22 C for the first six hours, and keep the salt under 1.6% for eye-forming styles.
Misread surface mould seen this make
Signal — A grey-green or black fuzzy patch on a rind that was supposed to be white or orange, or blue speckling on a hard cheese.
Cause — Wild Penicillium and Cladosporium from a cave with moving air and standing humidity. Also from brushing a good rind with a damp, dirty brush.
Fix — Distinguish before you discard: white felt and orange smear are wanted, green fuzz on a hard rind is surface only and rubs off with 3% brine. Black patches that pit the paste mean the wheel is lost.
Four things to carry forward
- Mixed culture, scald all the way to 42 C for a proper melt
- Press 18 kg for seven hours, brine at 22% for five hours per kilo
- Wash with 3% brine weekly, but only for four weeks
- Age three months; eat half of it raw