Why Two Jars

In Dr. Davis's 2025 update, B. subtilis HU58 replaces B. coagulans — but it can't share a jar with the others. HU58 reproduces about 50% faster than L. reuteri and L. gasseri, so fermented together it would dominate the blend before the other two hit their stride. It also prefers a cooler temperature. So you ferment two jars separately and combine them only at serving.

Jar 1: L. reuteri + L. gasseri

Crush 10 BioGaia Gastrus tablets and open one L. gasseri BNR17 capsule. Whisk them with 2 tablespoons of inulin and 2 tablespoons of the milk into a smooth slurry, then stir in the rest of the quart. Jar it with plastic lids and ferment at 100–106°F for 36 hours in your precision cooker. Keep the water below the lid line, or leave lids loose, so the small amount of gas can vent.

Jar 2: B. subtilis HU58

Empty one Microbiome Labs HU58 capsule into a second jar with 2 tablespoons of inulin and 2 tablespoons of milk. Whisk smooth, then stir in the rest of the quart. Ferment this jar cooler and shorter — 90–100°F for 24 hours. HU58 produces no CO2, so there's nothing to vent; just keep the bath water out of the jar.

Chill Both Jars

Refrigerate both jars once fermented. They thicken further as they cool — overnight is ideal.

Combine at Serving

Don't mix the whole batches. For each serving, stir about 1/2 cup of the reuteri–gasseri yogurt together with 2–3 tablespoons of the HU58 yogurt. This keeps each culture fermenting under its own ideal conditions while still giving you all three in the bowl.

Recultation and Troubleshooting

Reseed each jar from itself: 2–3 tablespoons of the reuteri blend, or 2 tablespoons of the HU58, into fresh milk and prebiotic. A weak batch usually shows up as a thinner texture or an odd (or absent) tanginess — reculture from a strong previous jar and double-check your temperatures with an independent thermometer.