Email us at info@jasperyeast.com or contact us at 205.790.2544. A friendly conversation via email or phone allows us to better understand the goals and expectations of each brew. We are currently working on our online ordering system.
All orders are shipped overnight with ice packs to keep the yeast cool until it reaches you. Upon arrival, yeast should be kept in a cold refrigerator until use. Local pickup for area brewers is available.
All of our propagations are tested for microbial contamination using well-known established ASBC/MBAA methods, and will only be released if no contamination is detected. All pitches are counted and validated for accurate cell number.
We use a number of plating and testing methods to validate the purity of a yeast pitch.The list below details several tests we perform in our QC/QA process.
Microbial Media
LCSM (Lin's Cupric Sulfate Medium)
LCSM is used for the detection of wild yeast populations in brewers yeast. It is designed to encourage the growth of non-Saccharomyces yeast. Some Saccharomyces, like many S. cerevisiae var. diastaticus, also grow on this media. We slightly adjusted commercial LCSM to be somewhat more promiscuous for diastaticus yeast.
LMDA (Lee's Multi-differential agar)
LMDA is used for the detection of bacteria often found in breweries.
LWYM (Lin's Wild Yeast Medium)
For the detection of wild yeast populations in brewers yeast. LWYM will encourage the growth of Saccharomyces wild yeasts primarily, but a number of non-Saccharomyces yeast may also be able to grow on this medium.
UBA (Universal Beer Agar)
We use UBA supplemented with cycloheximide to detect bacteria.
HLP (Hsu's Lactobacillus/Pediococcus)
We use HLP to detect anaerobic bacteria.
Lysine Medium
Lysine medium is a good third medium to catch contaminant yeast populations.
Bromophenol Blue Starch Plates
Only organisms that display diastatic activity can grow on this medium.
PCR Testing
For the rapid detection of beer spoilage organisms, specifically Saccharomyces var. diastaticus. The presence of the sta1 gene is a strong indication for the ability of this yeast to metabolize dextrins, that can potentially result in over-carbonation issues downstream.
