Watch: The Rough side of the Smoothie
Updated: Jun 22
Watch an insightful conversation between Rabbi Yitzchok Hisiger and Rabbi Sholom
Tendler, Kashrus Administrator of the Star-k. Enjoy the Q&A session discussing the various kashrus concerns related to smoothies.
There are few things as synonymous with summer as a fresh, cold fruit smoothie, a classic hot weather staple for many. During the summer months, the STAR-K hotline gets inundated with calls from consumers requesting guidance to ensure their smoothies are as kosher as they are delicious. While plain fruits and vegetables are often inherently kosher, several of them do have a major kashrus nemesis: bugs! Those perfect looking strawberries, raspberries, blackberries, and blueberries frequently host several common insects, like thrips, aphids and mites.
Another item that has been gaining popularity are juiced vegetables. Kale, cilantro and spinach are among the more popular vegetables that are juiced and then enjoyed as a drink. These, too, can present a significant challenge to ensure that they are insect free.
The following is a short guide to assist you in preparing your favorite kosher juiced or blended beverage.
No Checking Required
There are many delicious fruits and vegetables that do not present any issue of infestation and need no special preparation to be eaten whole or used in smoothies. These include apples, bananas, carrots, cherries, eggplants, grapefruits, lemons, limes, mangos, melons, nectarines, oranges, papayas, passion fruit, peaches, pineapples, plums, squashes and tomatoes.
For a complete list of fruits and vegetables that require checking, along with instructions for checking different types of produce, go to checkforinsects.com
Then there are berries. According to statista.com, strawberry is either the first or second most popular smoothie flavor in the United States (the other being banana). The insect issue with strawberries is well known and the process needed to clean them well documented. The question that rabbonim receive constantly is, “what if I am using frozen strawberries and blending them?” The answer to that question depends on a few factors. But first, the halachic background.
The Torah prohibitionof eating insects is severe. Depending upon the type of insect eaten, a person can violate as many as six Biblical prohibitions for each insect ingested. Furthermore, the negative spiritual effect that eating shratzim (insects) has on a person is particularly detrimental.
There are three categories defined by Halacha regarding the specific items that need to be checked:
Category 1: rov/muchzuk – something that is infested a majority of the time (over 50%)
Category 2: miyut hamatzui –something that contains a significant percentage of infestation, although less than a rov
Category 3: miyut sh’eino matzui –something that is infested rarely or infrequently
We all know that there is a concept in Halacha known as bitul (nullification). If a prohibited substance is present in a very small amount, typically 1:60, in many cases it is considered nullified and no longer prohibited. However, there are a couple of exceptions and caveats to this leniency.
First, there is a halachic concept of ein mevatlin issur l’chatchila (i.e., one may not perform the nullification process with specific intention to nullify the prohibited item). For example, if milk would fall into one’s cholent, but there is not enough to be 1:60, one is not allowed to add more cholent to the mixture in order to reach 1:60. Furthermore, if one would intentionally add more cholent for the purpose of achieving 1:60, it would not even help and the cholent would remain prohibited.
Secondly, if the prohibited substance is a complete entity (berya) like a whole insect, it is not able to be nullified at all, even if 1:60 is achieved.
When making a blended smoothie from fruits that have infestation concerns, the final product would likely have insect particles mixed inside. While distressing and unappetizing, the blended mixture meets the 1:60 threshold and avoids any concern of a berya so long as the mixture is of a smooth and fine consistency. The question then becomes: is this permissible to do?
If the items you are using are from Category #1 (rov/muchzuk, most of the time infested), it becomes difficult to justify making a smoothie from them. Items that fit this category would include raspberries, blackberries, curly kale (both conventional and organic) and pretty much all organic infestation-prone fruits or veggies. It would also include infestation-prone items that are pick-your-own. Since these farms need to allow people to roam their fields and orchards, fewer chemical pesticides are used, and the produce is considered for these purposes in the same category as organic. Making smoothies from items in category #1 is not permissible. Even to have it made for you by a non-Jew is not allowed. The fact that you are asking or ordering it to be made for you is considered the same as if you were making it yourself.
However, if the items you are using are in Category #2 (miyut hamatzui/sometimes infested), it is permitted to make a smoothie without needing to check the fruit first. Since your intention is to make a smoothie, not to specifically destroy the insects, there is no issue of ein mevatlin issur l’chatchila. This is known in Halacha as ein kavanaso l’vatel – your intention is not specifically to nullify the prohibited substance. In cases where the prohibited item (in this case, fruit) is only prohibited d’rabanan, (i.e. due the issur of berya), this is permissible.
This would mean that any conventional (non-organic) frozen strawberries or blueberries can be blended without the need to check first. If you are using conventional (non-organic) fresh fruit or veggie greens, they must be washed well prior to being juiced, but no actual checking is required. Unwashed fresh fruit or veggies even from this category cannot be used, as before they are washed they contain more insects and could possibly be considered rov/muchzuk (Category #1).
One important point to keep in mind is that the items need to be purchased or acquired with the intention to make smoothies. If they were purchased with the intent to use whole and later you realized that it isn’t permitted, a rav should be consulted to determine if you can still blend them. An evaluation needs to be made if this scenario would be considered mevatlin issur l’chatchila.
It should be noted though that longstanding STAR-K policy is to only allow our certified establishments to use fruits and vegetables that have been actually checked prior to use.
Juicing presents a slightly more complicated scenario since the vegetables are usually just squeezed or pressed, not blended. Squeezing does not necessarily destroy insects. Most juicers, however, have a filter which allows the water or juice to pass through and holds back the actual pieces of vegetable. If the filter is at least 200 mesh/70 microns, it would then effectively filter out any insects.
Smoothie Bars and Stores
Smoothie stores that prepare drinks to order may also present kashrus issues unless they are properly certified. Many times, organic fruits and vegetables are used. In addition, there are often grape juices added to some blends as a sweetener. ‘Fruit juice added’ can often refer to the addition of grape juice or a mix of juices that can possibly contain grape juice as well.
Furthermore, many smoothie establishments offer additives of whey, vitamin, and protein powders, all of which need reliable kosher certification.
Lastly, collagen powders have become very popular as an additive to healthy drinks and these are certainly not kosher. Therefore, we would recommend that consumers purchase smoothies only from stores or stands with reliable kosher certification.
For those who like to skip the article and get to the ‘bottom line,’ here are the key points to keep in mind:
Fruits/vegetables that have no insect concerns may be blended/juiced whether they are conventional or organic.
Fruits/vegetables that have some insect concerns and are conventional (with a few exceptions; see #3 below) can be blended into a smoothie so long as you purchased them with the intention to make smoothies.
Fruits/vegetables that have major insect concerns (e.g., raspberries, blackberries, and curly kale) and are either organic or conventional; all organic greens; and unwashed conventional fruits or leafy greens, may not be used in smoothies.
Smoothie bars/stores have a number of potential kashrus concerns and should be avoided unless they have proper kosher certification.
If you want to know the reasoning for any of the above, please read the article!
Feel free to call the STAR-K hotline with any kashrus or other Halacha questions. For more resources and guides to vegetable checking, go to www.checkforinsects.com.
Have a great, safe and gezunte summer!
 Many citrus fruits may have scales on the exterior peel, but the fruit is clean.
 Once properly peeled. IQF (Individual Quick Frozen) fruits are usually peeled adequately.
 The fact that any item is frozen does nothing to change its kashrus status vis-a-vis infestation. Insects actually are preserved perfectly well when frozen.
 There are three types of sheratzim: sheretz hamayim which is four lavin; sheretz ha’aretz which is five lavin; sheretz ha’of which is six lavin. The איסורים are listed in ויקרא פרק י”א and דברים פרק י”ד.
 ע’ שו”ת ודברת בם (פסקי הגר”ד פיינשטיין זצ”ל) סימן ר”י. וכן יעוין בספר בדיקת המזון כהלכה מאת הרב משה ויא שליט”א שער ראשון פרק א’ שמאריך בזה
 As we know, the Torah was not “given to angels,” and we are not expected to be able to avoid eating something which we can’t see. In truth, the insects we are discussing are all considered by Halacha to be visible to the naked eye, nir’eh l’einayim. This means that they can be seen without the aid of any special magnification or tools. A jeweler’s loupe or light box may be used to make checking easier, quicker, and more efficient, but they are not used to find insects that otherwise would not be visible due to their size ע’ אגרות משה יו”ד ח”ד סימן ב’. The fact that bugs can hide in the crevices of a strawberry or raspberry or in the folds of kale does not make them invisible to the naked eye (ע’ חכמת אדם כלל ל”ח סי’ ח’, ערוה”ש סי’ פ”ד סעיף ל”ו).
יו”ד צ”ט סעיף ה’ 
יו”ד ס’ ק’ סעיף א’ 
 As opposed to baby kale or Tuscan kale, which have much flatter leaves.
 This does not include organic fruits that are not known to harbor infestation, such as mangoes, cherries, etc.
 See דרכי תשובה ק”ח ס”ק כ’ However, buying pre-made blended items (i.e., not custom blended for you), like commercial raspberry juice, is permitted.
יו”ד סי’ פ”ד ש”ך ס”ק ל”ח וט”ז ס”ק כ’ 
 ‘Washing well’ means soaking in a detergent-based solution and rinsing thoroughly.
 Having an ‘intention’ does not require an actual verbal or non-verbal confirmation; so long as one has in mind when they are purchasing or acquiring a frozen item (e.g., strawberries) that its purpose is for smoothies, that is sufficient.
 This restriction does not apply to flat or baby kale.