BS"D
Eating Pachos M'kshiur on Yom Kippur
The Five-Minute Clock
If your Rav and your doctor have ruled that you may not fast a full day, you eat and drink pachos m'kshiur — less than the amount halacha counts as “eating.” Two rules make it work:
- Food: up to one small schnapps cup (about 1 oz / 25–30 cc) each time. Wait 9 minutes between eating.
- Drink: less than a cheekful (under 40 cc — half a mouthful is certainly less). Wait 5 minutes between drinking.
- Together: at one sitting you may eat the allowed food and drink the allowed drink.
Start on the hour. Then alternate: every ten minutes eat and drink; in between, drink only.
Red minuteseat the allowed amount and drink the allowed amount
Green minutesdrink the allowed amount only
- 10:00Eat and drink
- 10:05Drink
- 10:10Eat and drink
- 10:15Drink
- 10:20Eat and drink
- 10:25Drink
- 10:30Eat and drink
…and so on, every five minutes.
- Before the fast: measure the cup you will use — some “one-ounce” cups hold more. Prepare portions in advance.
- If you are low: a sweet drink is the preferred choice. If sugar and ketones are high, there is no shiur for drinking.
- If it is urgent: the waiting times can be shortened — ask your Rav beforehand what applies to you.
- A picture guide: The Halachos of K'zayis by Rabbi Yisroel Pinchos Bodner (Feldheim) has full-size photos of a k'zayis of common foods. A k'zayis is less than the Yom Kippur shiur (ככותבות), so any amount pictured there is permissible. English and Hebrew editions; in seforim stores and on Amazon.
Download the one-page PDF to print and carry.