pH measurement in food & beverages
Yoghurt, mash, ham: food is viscous, fatty, chunky - and sets pH measurement very particular tasks.
Why measurement happens here
In food production, the pH value decides safety, shelf life and taste at once. It steers the fermentation of yoghurt, cheese and sourdough, determines meat maturation (and with it tenderness and water binding), controls the preservation of pickled goods, and is a documented control point in many HACCP concepts. Measurement here is not curiosity - batches are released or rejected on its basis.
The peculiarity: it is rarely a clear liquid
A standard electrode with a spherical membrane is built for liquids. But food is often semi-solid or chunky - and that is exactly what the spear-tip electrode with its conical membrane is for, plunging directly into meat, a cheese wheel or dough. Even more rugged: ISFET sensors entirely without glass. In many plants they are the first choice, because a broken glass membrane in the product is not just a dead electrode but a foreign-body recall.
Proteins and fats: the electrode's enemies
Proteins deposit on the junction and clog it; fats coat the membrane with an insulating film. Both make the measurement sluggish and drifting. The remedies: a sleeve junction (mechanically cleanable), regular cleaning with pepsin-HCl solution against protein deposits and mild surfactant against fat - and consistent rinsing right after the measurement, before anything dries on.
Typical applications
- Meat: Spear measurement for maturation control (PSE/DFD detection) directly in the muscle.
- Dairy: Fermentation progress for yoghurt and cheese, curd-cutting timing.
- Brewing & beverages: Mash pH (target range around 5.2-5.6) for enzyme activity, wort and juice control.
- Baked goods: Sourdough management and dough acidification.
Matching products: Spear-tip electrodes and food measuring equipment are available in our shop aquaundco.com (German-language).