フリーズドライと乾燥野菜の違いとは？味・ロット・コストで選ぶ乾燥製法ガイド

"Dried vegetables," drawing attention against the backdrop of rising health consciousness and stockpiling needs. Among them, the ones whose properties differ greatly by production method areFreeze-dried(freeze-drying) andhot-air drying(air-drying). Even if they look similar, their inner nature is surprisingly little known. Understanding the differences and the pros and cons of the two, and selecting by use, reduces failure.

This article thoroughly compares the two in manufacturing method, taste and texture, and differences in cost and shelf stability. It further explains drying methods other than freeze-drying and hot-air drying, points for selecting a manufacturer when adopting them for commercial use, and use cases.

What is the difference between freeze-drying and hot-air drying?

First, let's nail down the principle and differences of each drying method. The processing temperature and technique produce large differences in the result and cost.

表のとおり、フリーズドライは戻りの速さと再現性で優れ、温風乾燥はコストと小ロット対応で優れます。どちらが上位というわけではなく、作りたい商品と発注ロットによって最適解が変わります。

ここでいちばん見落とされやすいのが、最下段のLotの行です。フリーズドライは装置が大きく、受託メーカーが示す量産ロットは乾燥前の原料換算でおおむね300〜1,000kg程度になります。「まず少量だけ試したい」という段階では、そもそもフリーズドライという選択肢が取りにくいという点は、商品企画の初期に知っておきたいところです。

身近な例が即席麺のかやくです。業界団体の解説では、乾燥方法のうち生産量がもっとも多いのは熱風乾燥で、主に野菜類に使われます。フリーズドライはたんぱく質を多く含む素材や香味野菜に採用されます。価格で選び分けているというより、素材の性質に合わせて製法を変えているわけです。

What is freeze-drying?

凍らせた食品を真空状態で乾燥させる「フリーズドライ」は、加熱せずに水分を抜いて保存性を高める手法です。もともと宇宙食や非常食の技術として発展してきましたが、現在では味噌汁やスナックなど日常の食品にも幅広く使われています。どんな素材がフリーズドライに向いているかはthe ranking of popular freeze-dry materials.

仕組みの中心にあるのが「昇華」です。凍らせた食品を真空に近い状態に置くと、内部の氷が液体の水を経由せず、直接水蒸気になって抜けていきます。加熱して水分を飛ばすわけではないため、香りや色の変化が起きにくいのが特徴です。

この方法を使うと、野菜の細胞構造がほぼそのまま残るため、形や食感を保ったまま保存できます。例えば、フリーズドライのSpinach,miso soup rehydrates in seconds just by pouring hot water, letting you enjoy a fresh-like taste. It also enables long-term storage of over a year, making it suited as emergency food too.

Pros and cons of freeze-drying

While highly functional and high-quality, caution is needed on cost and other aspects. Here we organize the representative strengths and weaknesses of freeze-drying.

Aspect	Evaluation	Details
色・香り・形	◎ Pro	凍結したまま乾かすため、加熱による変化が起きにくい
Speed of rehydration	◎ Pro	Rehydrates fluffy in an instant just by pouring hot water or water
Storage / transport	◎ Pro	Light and highly shelf-stable, strong for emergency-food and export uses too
Cost	△ Con	Because dedicated equipment and processing time are needed, cost tends to be high (for details, seethe benchmark and reduction methods for freeze-dry processing costs）
Flavor / dashi	△ Con	Dashi doesn't come out easily, making it somewhat unsuited for flavoring a whole dish (conversely, this is also the advantage that the material's taste doesn't transfer to others)

Summary of pros：戻りの速さと軽量性が最大の強み。非常食・輸出・高付加価値商品に向いています。

Summary of cons: High cost and unsuited to dashi-type dishes. It's a production method that comes into its own in high-unit-price products for BtoC.

What is hot-air drying (dried vegetables)?

Hot-air drying (air-drying) is a method that dries food by evaporating moisture with hot air of around 40–70°C. Because processing cost is relatively low and aroma and taste are concentrated, it is adopted widely—from miso soup ingredients and snacks to commercial vegetable materials.

食品業界では、果物や野菜をはじめ、肉、魚、穀物など幅広い食材の保存性向上や手軽な調理のために活用されています。温度帯は用途によって前後し、低温でじっくり乾かす場合もあれば、仕上げに高めの温度を使う場合もあります。Agritureではおよそ45℃を目安にした低温帯で乾燥させ、素材そのものの味が残る仕上がりを狙っています。

熱風乾燥が「料理向き」といわれる理由

熱風乾燥の持ち味は、煮出したときに味が出て、料理になじむことです。象徴的なのが切り干し大根で、煮汁を吸って味が染み、噛んだときの食感もしっかり残ります。日本には食材を干して使う調理の下地があり、和食の素材とは相性のよい製法です。

• 煮物・汁物で味が染みる。だしを取る素材にも向く
• 戻したあとも歯ごたえが残り、料理の具材として使いやすい
• 装置の大小が幅広く、生鮮1kg程度の少量からでも回せる

反対に、熱風乾燥が苦手なのが糖度の高い果物です。糖分が多いと水分が抜けにくく、しっかり乾かしたつもりでもセミドライの状態で止まることがあります。甘みが濃縮されて味そのものはおいしく仕上がる一方、水分が残るぶん保存性の設計が難しくなり、賞味期限を長く取りたい輸出向けでは扱いにくくなります。こうした素材はフリーズドライのほうが向きます。

Concrete example: hot-air-driedDried tomato
Hot-air-driedTomatois characterized by sweetness overflowing the more you chew and a firm texture. Used as dried tomato in salads, pasta, and the like, its distinctive flavor adds an accent to dishes.

Pros and cons of dried vegetables

Thanks to their flexibility in manufacturing and ease of handling, they are an ingredient easy for restaurants and processed-food businesses to use. Let's confirm the benefits, including price advantage, and the cautions.

Aspect	Evaluation	Details
Equipment cost	◎ Pro	Equipment cost is kept down, and small-lot support is possible
Texture	◎ Pro	The bite tends to remain, making it ideal for texture-focused dishes
How the flavor comes out	◎ Pro	煮出したときに味が出て、料理になじみやすい
色・香り	△ Con	熱がかかるため、色や香りは変化しやすい
Storage period	△ Con	Prone to moisture, with a shorter storage period than freeze-drying

Summary of pros: Low cost, small-lot support, and texture retention are the three reasons it's ideal for BtoB commercial use.

Summary of cons：色や香りが変化しやすい点と保存期間の短さが弱点。保存環境の管理と賞味期限設計が求められます。

There are 5 kinds of food-drying methods | Features, cost, and suited foods

Freeze-drying and hot-air drying are the two representative methods, but there are several other ways to dry food. Because the result, cost, minimum lot supported, and suited foods change by method, in product planning, deciding "which method to make it with" first makes manufacturer selection smooth.

Production method	Principle	Cost	Minimum lot	Suited foods
Freeze-drying	Freeze → sublimate in vacuum	High	300〜1,000kg〜	Miso soup, soup, rice porridge, fruit, baby food
Hot-air drying (air-drying)	Evaporate with hot air of 40–70°C	Cheap	100g〜	Vegetables, green onion, mushrooms, dashi materials
Spray drying	Spray liquid into a mist and dry it instantly	Medium	From tens of kg	Powdered soup, seasonings, powder
Turbo-drying	Dry in a short time with high-speed hot air	Medium	From a few kg	野菜パウダー・色や香りを残したい原料
Superheated-steam drying	Dry with steam over 100°C	Medium to high	From a few kg	Vegetables and aromatic materials that need sterilization

"Freeze-drying," suited to soups and fruits

湯戻しの速さを活かせるのがフリーズドライです。味噌汁・スープ・雑炊のような汁物、strawberryなど糖度の高いフルーツ、やわらかく戻したい離乳食に向きます。設備が大がかりなぶんコストは高く、量産ロットも乾燥前原料で300〜1,000kg程度になるため、ごく少量の試作には不向きです。ある程度の数量が見込める商品で選ばれます。

"Hot-air drying (air-drying)," suited to vegetable materials

The most versatile is hot-air drying. It suits vegetable materials such as green onion, mushrooms, and leafy greens, and materials boiled to take dashi, and its strength is that it's easy to support small-lot prototyping in units of 100g. At Agriture too, with hot-air and low-temperature air-drying of Kyoto vegetables and off-spec vegetables as our axis, we accept prototyping from small quantities (from Agriture's experience).

"Spray-drying, turbo-drying, and superheated steam," suited to powdering

When you want to process into "powder," such as powder or powdered soup, spray-drying and turbo-drying become candidates. At Agriture too we support powder processing of Kyoto vegetables and off-spec vegetables, and you can choose the method to suit the use. For aromatic vegetables where sterilization is emphasized, superheated-steam drying is sometimes used.

なお、お菓子への練り込みや飲料に溶かす用途では、私たちは熱風乾燥のパウダーを選ぶことが多いです。フリーズドライは素材の状態をそのまま保つぶん、配合したときに風味が立ちにくいと感じています。加工現場での実感ではありますが、パウダーの使いどころを決めるときの判断材料にしています。

Why dried vegetables are convenient for commercial use

Dried vegetables are a convenient ingredient used across diverse industries. Especially at restaurants and food manufacturers, adoption is advancing at many companies thanks to their shelf stability, convenience, and cost reduction. For small-lot ordering conditions, please also checkthe basics of freeze-dry minimum lots.

1. Long-term storage is possible and inventory management is easy

Dried vegetables have a longer storage period than raw vegetables and easy inventory management—a major benefit. Because they reduce food loss and achieve stable supply, they are economical for restaurants and food manufacturers.

2. Reduce cooking effort and make up for labor shortages

Because washing, cutting, and pre-processing are unnecessary, cooking effort can be greatly reduced. In the restaurant industry, where labor shortages are a challenge, and the food-processing industry, which seeks efficiency, they contribute to easing the operational burden.

3. Can supply at stable quality

Raw vegetables tend to fluctuate in quality and price with weather and season, but with dried vegetables, supply at stable quality is possible. Especially for companies that use large amounts of ingredients, uniformity of quality becomes a major advantage.

4. Reduce transport and storage costs

Because dried vegetables have their moisture removed and are lightweight, transport costs can be kept down. And because refrigerated or frozen storage is unnecessary, it also leads to reduced storage costs. This is a point food manufacturers and distributors want to nail down.

5. Can be used across a wide range of industries

Not limited to restaurants and food manufacturers, they can be used in diverse fields—nursing-care food, school lunches, disaster stockpiling, outdoor food, and more. Because you can choose a suited method such as freeze-drying or hot-air drying according to the use, they can flexibly meet the needs of each industry.

By use case | How to choose a drying method

Precisely because both processing methods are excellent, a choice suited to the use and purpose is required. We have summarized the optimal drying method by scene. As a representative example of fruit materials,the complete guide to choosing commercial freeze-dried strawberriesis also a helpful reference.

About Agriture's dried vegetable OEM service

At Agriture, centered on Kyoto-grown heirloom vegetables, we manufacture and roll out for OEM dried vegetables that are additive-free and use no glucose. Use cases by cut form, such as freeze-dried strawberry slices, are inhow to use freeze-dried strawberry slices.

Rather than comparing and searching for manufacturers, Agriture's strength is that you can consult directly about the product you want to make. Centered on Kyoto-grown vegetables, we support everything from prototyping to mass production, cut and powder processing, and packaging in an integrated way.

Item	Agriture's support
Supported production methods	Hot-air drying, low-temperature air-drying, powder processing
Minimum lot	Existing materials from 100g (drying processing of client-supplied materials is also possible)
Cut shape	Slice, julienne, powder, and other specifications possible
Main raw materials	Kyoto vegetables, heirloom vegetables, off-spec vegetables (additive-free, no glucose)
Supported industries	Restaurants, food processing, pet-food raw-material wholesale
Efforts	Sustainable manufacturing through agriculture-welfare collaboration and sixth-industrialization support

▶ For details, see the "Agriture's OEM Service" page.

FAQ

Choose the optimal drying method according to your purpose of use

フリーズドライと温風乾燥（乾燥野菜）は、それぞれ異なるメリットと制限を持ちます。戻りの速さや手軽さを求めるならフリーズドライ、コストや調理性、原料調達を重視するなら温風乾燥が適しています。スプレードライやターボドライまで含めて、作りたい商品に合う製法から逆算するとメーカー選びがスムーズです。

Choose the optimal drying method according to your purpose, and achieve both operational efficiency and quality.

規格外野菜・自社野菜での商品開発をお考えの方へ：企画から加工・資材・パッケージ印刷・ノベルティまで、窓口ひとつでご相談いただけます。→ 商品開発ワンストップの詳細はこちら