Bacillus subtilis BSCU1 Starter Culture — 3 × 500mg sachets 50 billion CFU per sachet | Home fermentation culture for cultured dairy

Bacillus subtilis BSCU1 Starter Culture — 3 × 500mg sachets 50 billion CFU per sachet | Home fermentation culture for cultured dairy

A high-potency single-strain starter culture for crafting cultured dairy at home. Each 500mg sachet contains a guaranteed minimum of 50 billion colony-forming units per gram of Bacillus subtilis strain BSCU1 — a robust, spore-forming culture selected for its consistent fermentation performance across a range of milk types and incubation conditions.

About the culture Bacillus subtilis BSCU1 is a heat-tolerant, naturally occurring food-grade microorganism with a long history of use in traditional fermented foods. The strain has been selected for its vigorous activity, predictable culture times, and stable performance in domestic yoghurt-maker conditions. Supplied as a freeze-dried powder for easy measuring and direct inoculation.

What it produces A smooth, mildly tangy cultured dairy ferment with a soft-set body. Texture, firmness, and flavour can be adjusted by varying milk fat content, incubation time, and temperature. Suitable for use with whole, low-fat, or non-homogenised cow's milk, and compatible with goat and sheep milk. 

Format 3 × 500mg sachets (1.5g total). Each sachet inoculates approximately 1–2 litres of milk.

A suitable replacement for HU58 in SIBO yoghurt.

SHIPPING INFORMATION:

Choose express shipping to ensure your fresh kefir grains arrive quickly and maintains their quality for the best results! Refrigerate on Arrival.

IMPORTANT: We only ship our yoghurt cultures on a Monday, Tuesday and Wednesday (as item is stored refrigerated) so that they do not remain in transit via Australia Post over the weekend

Best Before can be extended to 2 years by storing frozen

Frequently Asked Questions

What is Bacillus subtilis BSCU1? BSCU1 is a single-strain, food-grade culture of Bacillus subtilis — a spore-forming microorganism with a long history of use in traditional fermented foods. The BSCU1 designation refers to the specific strain selected for this product.

How is this different from a standard yoghurt culture? Conventional yoghurt cultures contain Lactobacillus bulgaricus and Streptococcus thermophilus, which produce the classic sharp, lactic flavour and firm set characteristic of yoghurt. BSCU1 is a different microorganism that produces a milder, smoother ferment with its own distinct flavour profile. The finished product is correctly labelled as cultured or fermented dairy rather than yoghurt.

How many batches can I make per sachet? Each 500mg sachet is formulated to inoculate 1–2 litres of milk. However you can reserve 2 tablespoons of prepared product to use as a starter for the next batch. This can be repeated up to 6 times before using a new sachet.

What milk works best? Fresh, pasteurised whole cow's milk gives the most consistent results. Low-fat, goat, and sheep milk also work well. UHT milk can be used without pre-heating. Plant-based milks are not recommended — the culture relies on dairy components for proper fermentation. However the culture can be combined with L reuteri and L gasseri for non dairy ferments.

Can I use raw milk? We recommend pasteurising milk by heating to 80 °C and holding for 10 minutes, then cooling to room temperature before inoculation. This deactivates competing wild microorganisms and gives the culture the cleanest environment to work in.

My ferment hasn't set after 36 hours — what went wrong? The most common causes are incubation temperature drift (below 38 °C slows the culture significantly), residual cleaning agents on jars, milk that was too hot when the culture was added (above 45 °C can damage the culture), or an expired sachet. Check your yoghurt maker's temperature with a thermometer and try a fresh sachet.

Can I reuse a spoonful of the finished batch as a starter for the next? Back-slopping (using a portion of the previous batch) can work for up to generations but results become inconsistent over time as the culture ratio shifts. For reliable, high-CFU results, start each batch with a fresh sachet.

How should I store unopened sachets? Sealed sachets are stable below 25 °C in a cool, dry place. For longest shelf life and maximum CFU retention, refrigerate or freeze. Once opened, use immediately — the culture is moisture-sensitive.

How long does the finished ferment keep? Refrigerate the finished product at or below 4 °C and consume within 7 days. Always use clean utensils when serving and discard if the product develops off-odours, discolouration, or unexpected texture.

What does it taste like? Mild, slightly tangy, and creamy — softer in flavour than traditional yoghurt. The taste develops with longer incubation; shorter ferments are gentler, longer ferments are more pronounced.

Is the culture suitable for vegetarians? Yes. The culture itself contains milk

Can I use this culture for anything other than dairy? This product has been formulated and tested for cultured dairy applications using a domestic yoghurt maker. It can be combined with L reuteri and L gasseri for non dairy products.