vaahtoihin

Vaahtoihin is the illative plural form of the Finnish noun vaahto, meaning foam or froth. It is used to express movement or direction into multiple foams, or into foams considered collectively. The form appears in instructional, culinary, and descriptive prose where the action targets more than one foam mass or a foam that can be divided into several portions.

Morphology and related forms: The illative plural suffix -iin attaches to the stem vaahto-, giving vaahtoihin. Other common forms of the word include the illative singular vaahtoon (into the foam), the partitive vaahtoa (some foam), and the genitive vaahtojen (of the foams). Finnish noun inflection follows regular patterns, so vaahto behaves like a standard third-declension noun with -o ending when declined in cases.

Usage and context: Vaahtoihin is commonly found in recipes and cooking instructions where an ingredient or mixture is added to whipped foam or into foams in multiple batches. For example, "Lisää sokeri vaahtoihin, vatkaa tasaiseksi" translates to “Add the sugar to the foams, whisk until smooth.” The plural illative is particularly natural when referring to several foam masses or to foam produced in more than one container, as opposed to vaahtoon, which would refer to a single foam mass.

See also: vaahto (foam), vaahdota/vaahtoa (to foam/whip), vaahdotus (foaming process).