In the evening kitchen, the kettle begins to hum. On a settled day, a toasty cup of tea can feel like exactly the thing. Turn the bag over, though, and it says nothing about caffeine. The answer lies in sources outside the bag.

Below: the amount in one cup, the guidance for pregnancy and for breastfeeding, and how the day adds up.

A cup of toasty steam

Cup the teacup in both hands and the scent of roasted leaf rises softly. Hojicha carries about as much caffeine as sencha.

In Japan's national food composition tables, the hojicha infusion carries the same figure as the sencha infusion. Roasting is sometimes said to remove caffeine, but a prefectural trial found even a dark roast lost only around a tenth. Being roasted does not make hojicha nearly caffeine-free.

Brew it stronger and the cup holds more. The figure on record is for a cup brewed under set conditions. How those conditions line up is taken further in Hojicha caffeine content vs sencha, bancha and black tea. Then there is pregnancy itself.

Setting the cup into the day's tally

On the wall calendar, check-up days are circled. In pregnancy, the guidance is set as a total for the day, not per cup.

The European body says that up to its daily figure, caffeine poses no health risk to the unborn child. The World Health Organization advises pregnant women with high intakes to cut back. In pregnancy, caffeine is described as clearing from the blood more slowly.

A cup of hojicha comes to roughly a seventh of the European daily figure [calculated].

Japan's national sleep guide says no clear effect on the fetus has been shown, yet several countries and societies advise keeping caffeine as low as possible. The sources go no further than the figures and how far apart they sit. Breastfeeding has guidance of its own.

A cup between feeds

After a night feed, only the small kitchen light is on. For breastfeeding, the guidance presented matches the figure for pregnancy.

The European body is presented as using the same figure for breastfeeding women, both for a single sitting and for the day. The Canadian body groups pregnant and breastfeeding women together, at a somewhat higher figure.

Since the figures differ by body, it is safer to read them as a range than to memorise one number. The day's tally also takes in drinks other than tea.

Coffee and black tea in the same ledger

A jar of coffee and a tin of black tea stand on the shelf too. The guidance figures cover everything eaten and drunk in a day.

Besides tea and coffee, soft drinks, chocolate and some over-the-counter medicines count in the same day. Japan's food safety commission notes that sensitivity varies widely, so no acceptable daily intake has been set. How many cups of hojicha to have comes down to subtracting what else was drunk.

Health and the course of pregnancy differ from person to person, so when in doubt, your doctor is the one to ask. What the sources offer is the material for the sum. Caffeine across drinks is laid out in one table in Hojicha caffeine: when, and for whom?. The figures and sources follow below.

The numbers in detail

One cup
In the Standard Tables of Food Composition in Japan (8th revised edition, 2023 supplement), hojicha infusion holds 0.02 g (20 mg) of caffeine per 100 mL. The conditions are 15 g of leaf, 650 mL of water at 90°C and 0.5 minutes. A 150 mL cup holds about 30 mg [calculated].
Roasting
In a Kochi Agricultural Research Center Tea Experiment Station trial (2014 data), a dark roast held 6–13% less caffeine than the unroasted tea, and a light roast hardly any less.
EFSA
Its 2015 scientific opinion finds that habitual intakes up to 200 mg a day in pregnancy raise no safety concern for the fetus. For breastfeeding women, up to 200 mg at once and 200 mg a day raise no health risk, as presented in the Food Safety Commission of Japan's fact sheet.
WHO
This is a recommendation from its 2016 antenatal care guideline. For pregnant women with high intakes above 300 mg a day, it advises lowering intake to reduce the risk of pregnancy loss and low birth weight. It lists tea, coffee, soft drinks, chocolate, energy drinks and some over-the-counter medicines as sources.
Clearance
The point that caffeine clears markedly more slowly from the mother's blood in pregnancy comes from the WHO recommendation as presented in the Food Safety Commission fact sheet.
Other bodies
In 2008 the UK Food Standards Agency lowered its pregnancy limit from 300 mg to 200 mg. Health Canada sets up to 300 mg a day for pregnant women, breastfeeding women and women planning a pregnancy. Both come from the Food Safety Commission fact sheet.
Japanese guidance
The MHLW Sleep Guide for Health Promotion 2023 says no clear research shows caffeine in pregnancy affecting the fetus. It adds that several countries and societies advise keeping caffeine as low as possible.
Share of the day
30 mg in a 150 mL cup is 15% of 200 mg [calculated]. None of the sources cited here gives separate public figures for early and late pregnancy.